Steve Hinder

Dr Steven Hinder


Experimental Officer, Manager of the Surface Analysis Laboratory
+44 (0)1483 689624
23 AB 03

Academic and research departments

Department of Mechanical Engineering Sciences.

My publications

Publications

Hinder SJ, Lowe C, Maxted JT, Watts JF (2005) The morphology and topography of polymer surfaces and interfaces exposed by ultra-low-angle microtomy, JOURNAL OF MATERIALS SCIENCE 40 (2) pp. 285-293 SPRINGER
The ultra-low-angle microtomy (ULAM) technique has been developed to impart a cross-sectional, ultra-low-angle taper through polymeric materials such as coatings and paints. ULAM employs a conventional rotary microtome in combination with high-precision, angled sectioning blocks to fabricate the ultra-low-angle tapers. Subsequent investigation of the tapers produced by ULAM may be used in conjunction with X-ray photoelectron spectroscopy (XPS) or time-of-flight secondary ion mass spectrometry (ToF-SIMS), for compositional depth profiling or ?buried? interface analysis. Variation in the selection of the ULAM taper angle and/or the analysis interval size employed enables depth resolution at the nanometre or micrometre scales to be achieved.

In the work described here scanning electron microscopy (SEM) and atomic force microscopy (AFM) have been employed to investigate the morphology and topography of the surfaces resulting from the ULAM tapering process. It is demonstrated that a correctly mounted polymeric sample, sectioned with a sharp microtome knife, displays little perturbation of the resulting polymeric surface after ULAM processing. Additionally, SEM analysis of the interface region between a poly(vinylidene fluoride) (PVdF) topcoat and polyurethane (PU) primer exposed by ULAM processing reveals that the interface region between the two coatings possesses a well-defined boundary. No evidence of polymeric smearing across the interface is observed. XPS compositional depth profiling across a ?buried? PVdF/PU interface, exposed by ULAM processing, is employed to demonstrate the utility of the ULAM technique.

Jenkins PG, Yang L, Thomason JL, Liggat JJ, Hinder SJ, Watts JF (2014) Regeneration of thermally recycled glass fibre for cost-effective composite recycling: Fundamental study of strength loss of thermally conditioned glass fibre, 16th European Conference on Composite Materials, ECCM 2014
Data produced using both unsized and aminopropyltriethoxysilane (APS) coated fibre will be shown and discussed. By applying a novel method of single fibre thermal conditioning (sf-TC) it was found that retained fibre strength is, in some cases, underestimated and that the temperature range 400-500 °C is the most critical for thermally induced strength loss. This is not related to degradation of the APS surface coating, but rather is likely linked to fundamental changes occurring in the glass network or at the fibre surface. X-ray Photoelectron Spectroscopy (XPS) analysis of treated fibres was performed, but it was not possible to measure any significant changes in surface chemical state. Analysis of water volatilized from unsized fibre was performed using a furnace connected to quadropole mass spectrometer. An asymptotic minimum in volatilized water is reached between 400-500 °C.
Danesh A, Davies MC, Hinder SJ, Roberts CJ, Tendler SJB, Williams PM, Wilkins MJ (2000) Surface characterization of aspirin crystal planes by dynamic chemical force microscopy, ANALYTICAL CHEMISTRY 72 (15) pp. 3419-3422 AMER CHEMICAL SOC
Lei C-H, Ouzineb K, Dupont O, Routh AF, Gundabala VR, Hinder SJ, Keddie JL (2007) Lateral distribution of surfactants in waterborne pressure sensitive adhesive films: Theory and experiment, ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY 233 AMER CHEMICAL SOC
Etacheri V, Michlits G, Seery MK, Hinder SJ, Pillai SC (2013) A highly efficient TiO2-xCx nano-heterojunction photocatalyst for visible light induced antibacterial applications., ACS Appl Mater Interfaces
Visible-light-induced antibacterial activity of carbon-doped anatase-brookite titania nano-heterojunction photocatalysts are reported for the first time. These heterostructures were prepared using a novel low temperature (100 °C) non-hydrothermal low power microwave (300 W) assisted method. Formation of interband C 2p states was found to be responsible for the band gap narrowing of the carbon doped heterojunctions. The most active photocatalyst obtained after 60 minutes of microwave irradiation exhibits a 2-fold higher visible-light induced photocatalytic activity in contrast to the standard commercial photocatalyst Evonik-Degussa P-25. Staphylococcus aureus inactivation rate constant for carbon-doped nano-heterojunctions and the standard photocatalyst was 0.0023 and -0.0081 min-1 respectively. It is proposed that the photo-excited electrons (from the C 2p level) are effectively transferred from the conduction band of brookite to that of anatase causing efficient electron-hole separation, which is found to be responsible for the superior visible-light induced photocatalytic and antibacterial activities of carbon-doped anatase-brookite nano-heterojunctions.
Ho R, Hinder SJ, Watts JF, Dilworth SE, Williams DR, Heng JYY (2010) Determination of surface heterogeneity of D-mannitol by sessile drop contact angle and finite concentration inverse gas chromatography, INTERNATIONAL JOURNAL OF PHARMACEUTICS 387 (1-2) pp. 79-86 ELSEVIER SCIENCE BV
Hinder SJ, Grilli R, Rustame M, Santos WIA, Baker MA, Costa I (2014) A surface analytical investigation of cerium-based conversion coatings deposited onto an AA2024-T3 aluminium alloy cladding layer, Surface and Interface Analysis 46 (10-11) pp. 735-739
Copyright © 2014 John Wiley & Sons, Ltd.Cerium-based conversion coatings are being investigated as alternatives to chromating treatments for the corrosion protection of aluminium and its alloys because of the environmentally unfriendly nature of the chromating process. This study investigates the surface film composition, structure and corrosion performance following a two-step surface treatment for an AA2024-T3 clad aluminium alloy. The two-step treatment comprised of an initial cerium conversion process involving immersion in an aqueous solution containing Ce3+ ions at 75°C followed by immersion in a propylene glycol solution at 75°C. The coating surface morphology, composition and structure have been studied using SEM, XPS, Auger spectroscopy and Fourier transform infrared spectroscopy, while corrosion resistance was evaluated using electrochemical impedance spectroscopy. The coating formed by the two-step treatment is an interconnecting fibrous (pseudo) boehmite layer with the incorporation of Ce3+ in the film. This two step treatment coating exhibits high impedance compared with the coatings formed through exposure to just stage 1 or stage 2 of the two-step treatment and shows good potential for improved corrosion protection.
Audronis M, Hinder SJ, MacK P, Bellido-Gonzalez V, Bussey D, Matthews A, Baker MA (2011) A comparison of reactive plasma pre-treatments on PET substrates by Cu and Ti pulsed-DC and HIPIMS discharges, Thin Solid Films 520 (5) pp. 1564-1570
Abstract PET web samples have been treated by magnetically enhanced glow discharges powered using either medium frequency pulse direct current (p-DC) or low frequency high power pulse (HIPIMS) sources. The plasma pre-treatment processes were carried out in an Ar-O2 atmosphere using either Cu or Ti sputter targets. XPS, AFM and sessile drop water contact angle measurements have been employed to examine changes in surface chemistry and morphology for different pre-treatment process parameters. Deposition of metal oxide onto the PET surface is observed as a result of the sputter magnetron-based glow discharge web treatment. Using the Cu target, both the p-DC and HIPIMS processes result in the formation of a thin CuO layer (with a thickness between 1 and 11 nm) being deposited onto the PET surface. Employing the Ti target, both p-DC and HIPIMS processes give rise to a much lower concentration of Ti (
Hinder SJ, Watts JF, Lowe C (2004) Interface analysis and compositional depth profiling by XPS of polymer coatings prepared using ultra-low-angle microtomy, SURFACE AND INTERFACE ANALYSIS 36 (8) pp. 1032-1036 JOHN WILEY & SONS LTD
Hinder SJ, Audronis M, Bellido-Gonzalez V, MacK P, Baker MA (2012) Surface characterisation of PET modified using a p-DC or HIPIMS reactive sputter pre-treatment, Surface and Interface Analysis 44 (8) pp. 1063-1067
Surface-sensitive techniques have been employed to characterise a model polymer substrate surface, poly(ethylene terephthalate) (PET), after a reactive sputter pre-treatment using magnetically enhanced Cu or Ti sputter targets in a mixed Ar-O 2 glow discharge plasma. The plasmas are produced using either medium-frequency pulsed direct current (p-DC) or low-frequency high power impulse (HIPIMS) sources. X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and sessile drop water contact angles were employed to investigate changes in PET surface chemistry and properties following surface modification using different p-DC and HIPIMS process parameters. The XPS results indicate that the chemical composition of plasma-treated PET surfaces (p-DC or HIPIMS) depends strongly on the processing parameters employed such as sputter target material, magnetic array type and power supply technology. XPS results demonstrate that the sputter target material employed is of primary importance as it dictates the quantity of metal deposited/implanted into the PET surface. XPS results show that the use of a Cu target resulted in
Kochur AG, Ivanova TM, Hinder SJ, Watts JF, Sidorov AA, Kiskin MA, Novotortsev VM, Eremenko IL (2011) X-ray photoelectron spectroscopy study of electron and spatial structure of mono- and binuclear Ni(II) carboxylate complexes with nitrogen-containing ligands, Journal of Electron Spectroscopy and Related Phenomena 184 (8-10) pp. 501-507
Ni3s, Ni3p and Ni2p x-ray photoelectron spectra of mono-and binuclear carboxylate complexes of nickel with various geometry of metal ions environment are obtained. The spectra are calculated in an isolated ion approximation. The dependence of the spectral profiles and the structure of the charge-transfer satellites on the structure of the immediate environment of nickel atoms is established. The data obtained support the results of X-ray diffraction and magnetic studies.
Nolan NT, Synnott DW, Seery MK, Hinder SJ, Van Wassenhoven A, Pillai SC (2011) Effect of N-doping on the photocatalytic activity of sol-gel TiO2, Journal of Hazardous Materials
Hinder SJ, Watts JF (2010) SIMS fingerprint analysis on organic substrates, SURFACE AND INTERFACE ANALYSIS 42 (6-7) pp. 826-829 WILEY-BLACKWELL
Shah UV, Olusanmi D, Narang AS, Hussain MA, Tobyn MJ, Hinder SJ, Heng JYY (2015) Decoupling the contribution of surface energy and surface area on the cohesion of pharmaceutical powders, Pharmaceutical Research 32 (1) pp. 248-259
© 2014 Springer Science+Business Media New York.Purpose: Surface area and surface energy of pharmaceutical powders are affected by milling and may influence formulation, performance and handling. This study aims to decouple the contribution of surface area and surface energy, and to quantify each of these factors, on cohesion. Methods: Mefenamic acid was processed by cryogenic milling. Surface energy heterogeneity was determined using a Surface Energy Analyser (SEA) and cohesion measured using a uniaxial compression test. To decouple the surface area and surface energy contributions, milled mefenamic acid was "normalised" by silanisation with methyl groups, confirmed using X-ray Photoelectron Spectroscopy. Results: Both dispersive and acid-base surface energies were found to increase with increasing milling time. Cohesion was also found to increase with increasing milling time. Silanised mefenamic acid possessed a homogenous surface with a surface energy of 33.1?±?1.4 mJ/m2, for all milled samples. The cohesion for silanised mefenamic acid was greatly reduced, and the difference in the cohesion can be attributed solely to the increase in surface area. For mefenamic acid, the contribution from surface energy and surface area on cohesion was quantified to be 57% and 43%, respectively. Conclusions: Here, we report an approach for decoupling and quantifying the contribution from surface area and surface energy on powder cohesion.
Hinder SJ, Watts JF, Lowe C (2006) Surface and interface analysis of complex polymeric paint formulations, SURFACE AND INTERFACE ANALYSIS 38 (4) pp. 557-560 JOHN WILEY & SONS LTD
Ozsan ME, Sellin PJ, Veeramani P, Hinder SJ, Monnier MLT, Prekas G, Lohstroh A, Baker MA (2010) Chemical etching and surface oxidation studies of cadmium zinc telluride radiation detectors, SURFACE AND INTERFACE ANALYSIS 42 (6-7) pp. 795-798 WILEY-BLACKWELL
Stobie N, Duffy B, Colreavy J, McHale P, Hinder SJ, McCormack DE (2010) Dual-action hygienic coatings: Benefits of hydrophobicity and silver ion release for protection of environmental and clinical surfaces, JOURNAL OF COLLOID AND INTERFACE SCIENCE 345 (2) pp. 286-292 ACADEMIC PRESS INC ELSEVIER SCIENCE
Periyat P, Pillai SC, McCormack DE, Colreavy J, Hinder SJ (2008) Improved high-temperature stability and sun-light-driven photocatalytic activity of sulfur-doped anatase TiO2, JOURNAL OF PHYSICAL CHEMISTRY C 112 (20) pp. 7644-7652 AMER CHEMICAL SOC
Nolan NT, Seery MK, Hinder SJ, Healy LF, Pillai SC (2010) A Systematic Study of the Effect of Silver on the Chelation of Formic Acid to a Titanium Precursor and the Resulting Effect on the Anatase to Rutile Transformation of TiO2, JOURNAL OF PHYSICAL CHEMISTRY C 114 (30) pp. 13026-13034 AMER CHEMICAL SOC
Hinder S, Watts J, Simmons G, Lowe C (2008) An investigation of the distribution of minor components in complex polymeric paint formulations using ToF-SIMS depth profiling, SURFACE AND INTERFACE ANALYSIS 40 (3-4) pp. 436-440 JOHN WILEY & SONS LTD
Zhang WR, Hinder SJ, Smith R, Lowe C, Watts JF (2011) An investigation of the effect of pigment on the degradation of a naturally weathered polyester coating, JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH 8 (3) pp. 329-342 SPRINGER
Stobie N, Duffy B, Hinder SJ, McHale P, McCormack DE (2009) Silver doped perfluoropolyether-urethane coatings: Antibacterial activity and surface analysis, COLLOIDS AND SURFACES B-BIOINTERFACES 72 (1) pp. 62-67 ELSEVIER SCIENCE BV
Shah UV, Olusanmi D, Narang AS, Hussain MA, Tobyn MJ, Hinder SJ, Heng JY (2014) Decoupling the contribution of surface energy and surface area on the cohesion of pharmaceutical powders., Pharm Res 32 (1) pp. 248-259
PURPOSE: Surface area and surface energy of pharmaceutical powders are affected by milling and may influence formulation, performance and handling. This study aims to decouple the contribution of surface area and surface energy, and to quantify each of these factors, on cohesion. METHODS: Mefenamic acid was processed by cryogenic milling. Surface energy heterogeneity was determined using a Surface Energy Analyser (SEA) and cohesion measured using a uniaxial compression test. To decouple the surface area and surface energy contributions, milled mefenamic acid was "normalised" by silanisation with methyl groups, confirmed using X-ray Photoelectron Spectroscopy. RESULTS: Both dispersive and acid-base surface energies were found to increase with increasing milling time. Cohesion was also found to increase with increasing milling time. Silanised mefenamic acid possessed a homogenous surface with a surface energy of 33.1 ± 1.4 mJ/m(2) , for all milled samples. The cohesion for silanised mefenamic acid was greatly reduced, and the difference in the cohesion can be attributed solely to the increase in surface area. For mefenamic acid, the contribution from surface energy and surface area on cohesion was quantified to be 57% and 43%, respectively. CONCLUSIONS: Here, we report an approach for decoupling and quantifying the contribution from surface area and surface energy on powder cohesion.
Hinder SJ, Connell SD, Davies MC, Roberts CJ, Tendler SJB, Williams PM (2002) Compositional mapping of self-assembled monolayers derivatized within microfluidic networks, LANGMUIR 18 (8) pp. 3151-3158 AMER CHEMICAL SOC
Ferreira JM, Rossi JL, Baker MA, Hinder SJ, Costa I (2014) Deposition and characterization of a new mixed organic/inorganic cerium containing coating for the corrosion protection of eletrogalvanized steel, International Journal of Electrochemical Science 9 (4) pp. 1827-1839
Protective coatings have been deposited on electrogalvanized steel by immersion in solutions containing 2-Butyne-1.4-diol propoxylate (C7H11O3), cerium nitrate, sodium nitrate and sodium sulphate for different immersion periods. The surface morphology and chemical composition of the coatings formed on the electrogalvanized steel were studied using field emission gun scanning electron microscopy, X-ray photoelectron spectroscopy and Fourier Transform Infrared Spectroscopy. The corrosion resistance of the electrogalvanized steel prior to and after surface treatment was investigated by electrochemical impedance spectroscopy in 0.1 mol L-1 NaCl solution. The results were compared to the performance of a chromate conversion coating in the same solution. The coatings formed on the electrogalvanized steel surface showed the presence of a mixed organic/inorganic layer containing Ce2O3 and CeO2 which improved the corrosion resistance of the substrate and showed a superior corrosion resistance to that provided by a chromate conversion coating.
Pillai SC, Periyat P, George R, McCormack DE, Seery MK, Hayden H, Colreavy J, Corr D, Hinder SJ (2007) Synthesis of high-temperature stable anatase TiO2 photocatalyst, JOURNAL OF PHYSICAL CHEMISTRY C 111 (4) pp. 1605-1611 AMER CHEMICAL SOC
Foerster A, Holowacz I, Kumar GBS, Anandakumar S, Wall JG, Wawrzynska M, Paprocka M, Kantor A, Kraskiewicz H, Olsztynska-Janus S, Hinder SJ, Bialy D, Podbielska H, Kopaczynska M (2016) Stainless steel surface functionalization for immobilization of antibody fragments for cardiovascular applications, JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A 104 (4) pp. 821-832 WILEY-BLACKWELL
Etacheri V, Seery MK, Hinder SJ, Pillai SC (2011) Oxygen Rich Titania: A Dopant Free, High Temperature Stable, and Visible-Light Active Anatase Photocatalyst, ADVANCED FUNCTIONAL MATERIALS 21 (19) pp. 3744-3752 WILEY-V C H VERLAG GMBH
Fagan R, McCormack DE, Hinder SJ, Pillai SC (2016) Photocatalytic Properties of g-C3N4-TiO2 Heterojunctions under UV and Visible Light Conditions, MATERIALS 9 (4) ARTN 286 MDPI AG
Sani SFA, Mahdiraji GA, Shafiqah ASS, Grime GW, Palitsin V, Hinder SJ, Tamchek N, Rashid HAA, Maah MJ, Watts JF, Bradley DA (2015) XPS and PIXE Analysis of Doped Silica Fibre for Radiation Dosimetry, JOURNAL OF LIGHTWAVE TECHNOLOGY 33 (11) pp. 2268-2278 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Stobie N, Duffy B, McCormack DE, Colreavy J, Hidalgo M, McHale P, Hinder SJ (2008) Prevention of Staphylococcus epidermidis biofilm formation using a low-temperature processed silver-doped phenyltriethoxysilane sol-gel coating, BIOMATERIALS 29 (8) pp. 963-969 ELSEVIER SCI LTD
Leyland NS, Podporska-Carroll J, Browne J, Hinder SJ, Quilty B, Pillai SC (2016) Highly Efficient F, Cu doped TiO2 anti-bacterial visible light active photocatalytic coatings to combat hospital-acquired infections, SCIENTIFIC REPORTS 6 ARTN 24770 NATURE PUBLISHING GROUP
Padmanabhan SC, Pillai SC, Colreavy J, Balakrishnan S, McCormack DE, Perova TS, Gun'ko Y, Hinder SJ, Kelly JM (2007) A simple sol-gel processing for the development of high-temperature stable photoactive anatase titania, CHEMISTRY OF MATERIALS 19 (18) pp. 4474-4481 AMER CHEMICAL SOC
Jaoude MA, Polychronopoulou K, Hinder SJ, Katsiotis MS, Baker MA, Greish YE, Alhassan SM (2016) Synthesis and properties of 1D Sm-doped CeO2 composite nanofibers fabricated using a coupled electrospinning and sol-gel methodology, CERAMICS INTERNATIONAL 42 (9) pp. 10734-10744 ELSEVIER SCI LTD
Kalarivalappil V, Divya CM, Wunderlich W, Pillai SC, Hinder SJ, Nageri M, Kumar V, Vijayan BK (2016) Pd Loaded TiO2 Nanotubes for the Effective Catalytic Reduction of p-Nitrophenol, CATALYSIS LETTERS 146 (2) pp. 474-482 SPRINGER
Gravani S, Polychronopoulou K, Stolojan V, Cui Q, Gibson PN, Hinder SJ, Gu Z, Doumanidis CC, Baker MA, Rebholz C (2010) Growth and characterization of ceria thin films and Ce-doped gamma-Al2O3 nanowires using sol-gel techniques, NANOTECHNOLOGY 21 (46) ARTN 465606 IOP PUBLISHING LTD
Etacheri V, Seery MK, Hinder SJ, Pillai SC (2012) Nanostructured Ti(1-x)S(x)O(2-y)N(y) heterojunctions for efficient visible-light-induced photocatalysis., Inorg Chem 51 (13) pp. 7164-7173
Highly visible-light-active S,N-codoped anatase-rutile heterojunctions are reported for the first time. The formation of heterojunctions at a relatively low temperature and visible-light activity are achieved through thiourea modification of the peroxo-titania complex. FT-IR spectroscopic studies indicated the formation of a Ti(4+)-thiourea complex upon reaction between peroxo-titania complex and thiourea. Decomposition of the Ti(4+)-thiourea complex and formation of visible-light-active S,N-codoped TiO(2) heterojunctions are confirmed using X-ray diffraction, Raman spectroscopy, transmission electron microscopy, and UV/vis spectroscopic studies. Existence of sulfur as sulfate ions (S(6+)) and nitrogen as lattice (N-Ti-N) and interstitial (Ti-N-O) species in heterojunctions are identified using X-ray photoelectron spectroscopy (XPS) and FT-IR spectroscopic techniques. UV-vis and valence band XPS studies of these S,N-codoped heterojunctions proved the fact that the formation of isolated S 3p, N 2p, and  * N-O states between the valence and conduction bands are responsible for the visible-light absorption. Titanium dioxide obtained from the peroxo-titania complex exists as pure anatase up to a calcination temperature as high as 900 °C. Whereas, thiourea-modified samples are converted to S,N-codoped anatase-rutile heterojunctions at a temperature as low as 500 °C. The most active S,N-codoped heterojunction 0.2 TU-TiO(2) calcined at 600 °C exhibits a 2-fold and 8-fold increase in visible-light photocatalytic activities in contrast to the control sample and the commercial photocatalyst Degussa P-25, respectively. It is proposed that the efficient electron-hole separation due to anatase to rutile electron transfer is responsible for the superior visible-light-induced photocatalytic activities of S,N-codoped heterojunctions.
Hinder SJ, Lowe C, Watts JF (2007) ToF-SIMS depth profiling of a complex polymeric coating employing a C-60 sputter source, SURFACE AND INTERFACE ANALYSIS 39 (6) pp. 467-475 JOHN WILEY & SONS LTD
Audronis M, Hinder SJ, Mack P, Bellido-Gonzalez V, Bussey D, Matthews A, Baker MA (2011) A comparison of reactive plasma pre-treatments on PET substrates by Cu and Ti pulsed-DC and HIPIMS discharges, Thin Solid Films 520 (5) pp. 1564-1570 Elsevier
PET web samples have been treated by magnetically enhanced glow discharges powered using either medium frequency pulse direct current (p-DC) or low frequency high power pulse (HIPIMS) sources. The plasma pre-treatment processes were carried out in an Ar?O2 atmosphere using either Cu or Ti sputter targets. XPS, AFM and sessile drop water contact angle measurements have been employed to examine changes in surface chemistry and morphology for different pre-treatment process parameters. Deposition of metal oxide onto the PET surface is observed as a result of the sputter magnetron-based glow discharge web treatment. Using the Cu target, both the p-DC and HIPIMS processes result in the formation of a thin CuO layer (with a thickness between 1 and 11 nm) being deposited onto the PET surface. Employing the Ti target, both p-DC and HIPIMS processes give rise to a much lower concentration of Ti (
Synnott DW, Seery MK, Hinder SJ, Colreavy J, Pillai SC (2013) Novel microwave assisted synthesis of ZnS nanomaterials, Nanotechnology 24 (4)
A novel ambient pressure microwave assisted technique is developed in which silver and indium-modified ZnS is synthesized. The as-prepared ZnS is characterized by x-ray diffraction, UV-vis spectroscopy, x-ray photoelectron spectroscopy and luminescence spectroscopy. This procedure produced crystalline materials with particle sizes below 10 nm. The synthesis technique leads to defects in the crystal which induce mid-energy levels in the band gap and lead to indoor light photocatalytic activity. Increasing the amount of silver causes a phase transition from cubic blende to hexagonal phase ZnS. In a comparative study, when the ZnS cubic blende is heated in a conventional chamber furnace, it is completely converted to ZnO at 600 °C. Both cubic blende and hexagonal ZnS show excellent photocatalytic activity under irradiation from a 60 W light bulb. These ZnS samples also show significantly higher photocatalytic activity than the commercially available TiO2 (Evonik-Degussa P-25). © 2013 IOP Publishing Ltd.
Subramanian G, Nalawade P, Hinder SJ, Pillai SC, Prakash H (2015) Nickel azamacrocyclic complex activated persulphate based oxidative degradation of methyl orange: recovery and reuse of complex using adsorbents, RSC ADVANCES 5 (40) pp. 31716-31724 ROYAL SOC CHEMISTRY
© The Royal Society of Chemistry 2015.Adsorbents are useful for the removal of metal complex based catalysts from the reaction medium. Moreover, effective catalysts may be recycled with the use of adsorbents. These facts inspired us to investigate the use of adsorbents for the recovery and reuse of a metal complex that could activate persulphate to effectively degrade an organic pollutant in water. Herein, we report the nickel complex (C1) activated persulphate based degradation of methyl orange (MO) in water and the removal of C1 using activated carbon (AC) and Amberlite (Am) as adsorbents. C1 adsorbed onto AC (C1-AC) was reused in the solid form to activate persulphate and degrade MO without leaching C1 into water. Additionally, solid C1-Am recovered from the degraded MO solution was ion exchanged using sodium chloride to obtain C1, which was reused for MO degradation. The study demonstrates the application of adsorbents such as AC and Am for the adsorptive recovery and reuse of a metal complex based persulphate activator.
Shah UV, Parambil JV, Williams DR, Hinder SJ, Heng JYY (2015) Preparation and characterisation of 3D nanotemplates for protein crystallisation, POWDER TECHNOLOGY 282 pp. 10-18 ELSEVIER SCIENCE BV
© 2015 Elsevier B.V. Heterogeneous template nucleants are gaining pace as a favoured tool for crystallisation of proteins that may be otherwise difficult to crystallise. A systematic understanding on protein-nucleant interactions has to be developed to enable the development of nucleants for a wide spectrum of biological macromolecules. Thorough characterisation of the nucleants is the key starting point to achieve this aim. This report focuses on the method to produce and characterise functionalised 3D nanotemplates with controlled porosity in the range of 3-22. nm and surface chemistry that can vary from highly hydrophilic to highly hydrophobic in nature. BET and TEM are used to study porosity and pore size distribution while contact angle, XPS and zeta potential are used to investigate surface chemistry of the nucleants. These functionalised 3D nanotemplates are hereby reported to produce protein crystals (concanavalin A and catalase) of different habits without changing any other crystallisation parameters other than the surface chemistry of the templates. This emphasises the potential of 3D nanotemplates with well-ordered porosity and chemistry for further development in protein crystallisation experiments.
Periyat P, McCormack DE, Hinder SJ, Pillai SC (2009) One-Pot Synthesis of Anionic (Nitrogen) and Cationic (Sulfur) Codoped High-Temperature Stable, Visible Light Active, Anatase Photocatalysts, JOURNAL OF PHYSICAL CHEMISTRY C 113 (8) pp. 3246-3253 AMER CHEMICAL SOC
Hinder SJ, Lowe C, Maxted JT, Watts JF (2004) A ToF-SIMS investigation of a buried polymer/polymer interface exposed by ultra-low-angle microtomy, SURFACE AND INTERFACE ANALYSIS 36 (12) pp. 1575-1581 JOHN WILEY & SONS LTD
The interfacial region of a model, multilayer coating system on an aluminium substrate has been investigated by high resolution time-of-flight secondary ion mass spectrometry (ToF-SIMS). Employing ultra-low-angle microtomy (ULAM), the interface between a poly(vinylidene difluoride) (PVdF) based topcoat and a poly(urethane) (PU) based primer ?buried? over 20¼m below the PVdF topcoat?s air/coating surface was exposed. Imaging ToF-SIMS and subsequent post-processing extraction of mass spectra of the ULAM exposed interface region and the PVdF topcoat and PU primer bulks indicates that the material composition of the polymer-polymer interface region is substantially different to that of the bulk PVdF and PU coatings. Analysis of the negative ion mass spectra obtained from the PVdF/PU interface reveals the presence of a methacrylate based component or additive at the interface region. Reviewing the topcoat and primer coating formulations reveals the PVdF topcoat formulation contains methyl methacrylate (MMA)/ethyl acrylate (EA) acrylic co-polymer components. Negative ion ToF-SIMS analysis of an acrylic co-polymer confirms it is these components that are observed at the PVdF/PU interface. Post-processing extraction of ToF-SIMS images based on the major ions of the MMA/EA co-polymers reveals these components are observed in high concentration at the extremities of the PVdF coating i.e. at the polymer-polymer interface but are also observed to be distributed evenly throughout the bulk of the PVdF topcoat. These findings confirms that a fraction of the MMA/EA acrylic co-polymers in the formulation segregate to the topcoat-primer interface where they enhance the adhesive properties exhibited by the PVdF topcoat towards the underlying PU primer substrate.
Podporska-Carroll J, Myles A, Quilty B, McCormack DE, Fagan R, Hinder SJ, Dionysiou DD, Pillai SC (2015) Antibacterial properties of F-doped ZnO visible light photocatalyst., J Hazard Mater
Nanocrystalline ZnO photocatalysts were prepared by a sol-gel method and modified with fluorine to improve their photocatalytic anti-bacterial activity in visible light. Pathogenic bacteria such as Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) were employed to evaluate the antimicrobial properties of synthesized materials. The interaction with biological systems was assessed by analysis of the antibacterial properties of bacteria suspended in 2% (w/w) powder solutions. The F-doping was found to be effective against S. aureus (99.99% antibacterial activity) and E. coli (99.87% antibacterial activity) when irradiated with visible light. Production of reactive oxygen species is one of the major factors that negatively impact bacterial growth. In addition, the nanosize of the ZnO particles can also be toxic to microorganisms. The small size and high surface-to-volume ratio of the ZnO nanoparticles are believed to play a role in enhancing antimicrobial activity.
Fisher MB, Keane DA, Fernández-Ibáñez P, Colreavy J, Hinder SJ, McGuigan KG, Pillai SC (2013) Nitrogen and copper doped solar light active TiO2 photocatalysts for water decontamination, Applied Catalysis B: Environmental 130-131 pp. 8-13
A novel class of photocatalytic coating capable of degrading bacterial and chemical contaminants in the presence of visible sunlight wavelengths was produced by depositing a stable photocatalytic TiO2 film on the internal lumen of glass bottles via a sol-gel method. This coating was prepared in either undoped form or doped with nitrogen and/or copper to produce visible light-active TiO2 films which were annealed at 600°C and were characterized by Raman and X-ray photoelectron spectroscopy. The presence of doped and undoped TiO2 films was found to accelerate the degradation of methylene blue in the presence of natural sunlight, while copper-doped TiO2 films were found to accelerate bacterial inactivation (of Escherichia coli and Enterococcus faecalis) in the presence of natural sunlight. © 2012 Elsevier B.V.
Etacheri V, Seery MK, Hinder SJ, Pillai SC (2010) Highly Visible Light Active TiO2-xNx Heterojunction Photocatalysts, CHEMISTRY OF MATERIALS 22 (13) pp. 3843-3853 AMER CHEMICAL SOC
Parambil JV, Poornachary SK, Hinder SJ, Tan RBH, Heng JYY (2015) Establishing template-induced polymorphic domains for API crystallisation: the case of carbamazepine, CRYSTENGCOMM 17 (33) pp. 6384-6392 ROYAL SOC CHEMISTRY
Nolan NT, Synnott DW, Seery MK, Hinder SJ, Van Wassenhoven A, Pillai SC (2011) Effect of N-doping on the photocatalytic activity of sol-gel TiO(2)., J Hazard Mater
In order to study the visible light photocatalytic activity of nitrogen doped titanium dioxide, the interaction between nitrogen dopant sources and titania precursors during sol-gel synthesis is investigated. N-TiO(2) was synthesised using the sol-gel method using 1,3-diaminopropane as a nitrogen source. Samples were annealed several temperatures and the percentage of rutile present determined by X-ray diffraction to be 0% (500°C), 46% (600°C), and 94% (700°C). The reducing amounts of anatase at higher temperatures are studied using FTIR, which suggests the absence of any polymeric chains formed by the chelating agents, which would normally extend anatase-to-rutile transformation temperatures. Differential scanning calorimetry shows that crystalliation occurs before 500°C, providing the crystalline form determined by XRD at 500°C. Increased temperature also resulted in diminished visible light absorption capability, with only the 500°C sample showing significant absorption in the visible region. XPS studies revealed that nitrogen remained within the TiO(2) lattice at higher temperatures. Consequent with the reduced visible light absorption capacity, photocatalytic activity also reduced with increased annealing temperature. Degradation kinetics of methylene blue, irradiated with a 60W house-bulb, resulted in first order degradation rates constants of 0.40×10(-2), 0.19×10(-2), and 0.22×10(-2)min(-1) for 500, 600, and 700°C respectively. Degradation of Degussa P25 was minimal under the same conditions, and that of undoped TiO(2) was 0.02×10(-2)min(-1). Similarly, using 4-chlorophenol under solar irradiation conditions, the N-doped sample at 500°C substantially out-performed the undoped sample. These results are discussed in the context of the effect of increasing temperature on the nature of the band gap.
Hinder SJ, Lowe C, Maxted JT, Watts JE (2005) Migration and segregation phenomena of a silicone additive in a multilayer organic coating, PROGRESS IN ORGANIC COATINGS 54 (2) pp. 104-112 ELSEVIER SCIENCE SA
The migration and segregation of a minor silicone containing additive in a multilayer, organic coating system has been investigated by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The silicone containing additive employed was the most compatible thermally stable, polyester modified poly(dimethyl siloxane) (PDMS) flow agent. A polyester/polyurethane (PU) based primer and a poly(vinylidene difluoride) (PVdF) based topcoat on an aluminium substrate were used as a model, multilayer, organic coating system. XPS and SIMS characterisation of the PU primer formulation (with and without addition of the PDMS based flow agent), confirmed that the PDMS based flow agent segregated to the PU primers air/coating surface. Characterisation of the PVdF topcoats air/coating surface, after application and curing over the PU primers, revealed the presence of the PDMS based flow agent at the PVdF air/coating surface when the topcoat was applied to the PU primer containing the PDMS based flow agent. Ultra-low-angle microtomy (ULAM) was employed to produce an ultra-low-angle taper that passes through the entire thickness of the PVdF topcoat (~20 µm). XPS linescan analysis along the ULAM taper indicated that the PDMS based flow agent had migrated from the PU primer surface into the bulk of the PVdF topcoat. Analysis of the shape of the silicon concentration profile revealed the existence of a silicon concentration gradient and indicated that the PDMS based flow agent was segregating towards the PVdF topcoats air/coating surface. Such migration and segregation phenomena have major implications for formulators in the coatings/paint industries.
Hinder SJ, Lowe C, Maxted JT, Perruchot C, Watts JE (2005) Intercoat adhesion failure in a multilayer organic coating system: An X-ray photoelectron spectroscopy study, PROGRESS IN ORGANIC COATINGS 54 (1) pp. 20-27 ELSEVIER SCIENCE SA
The strength of intercoat adhesion exhibited between a series of polyester/polyurethane (PU) based primer formulations and a standard poly(vinylidene difluoride) (PVdF) based topcoat formulation has been investigated by X-ray photoelectron spectroscopy (XPS). An initial XPS study of changes in surface elemental composition (induced by variation of the peak metal temperature (PMT) achieved during thermal curing), on a subset of the PU primers employed, indicates that beyond a PMT of 232°C changes in PU primer surface composition are negligible. A reference PU primer coating formulation and four variations of this formulation, produced by including, excluding or substituting components/additives in the reference formulation, are characterised by XPS. The PU primer formulation in which a flow agent additive is included exhibits segregation of the flow agent to the primer surface. The PU primer and PVdF topcoat intercoat adhesion failure surfaces resulting from failure at or near the PVdF/PU interface as a result of a peel test are also characterised by XPS. Additionally the PVdF topcoat air-coating surface is characterised by XPS. The interface analyses for the flow agent containing PU primer formulation indicates stripping of the flow agent layer from the PU primer and transfer of the flow agent to the PVdF topcoat interfacial failure surface. Similarly, PU primer formulations in which the concentrations of a crosslinking resin are changed demonstrate that the transfer of carbon and oxygen containing materials from the PU primer to the PVdF topcoat occurs, due to insufficient crosslinking of the polyester component of the PU primer formulation. These results suggest a correlation between the nitrogen concentration at the PU primer surface and the strength of the intercoat adhesion exhibited by the PU primer towards the PVdF topcoat.
Zhang WR, Hinder SJ, Smith R, Lowe C, Watts JF (2010) An investigation of the effect of pigment on the degradation of a naturally weathered polyester coating, Journal of Coatings Technology Research pp. 1-14
Lei C-H, Ouzineb K, Dupont O, Routh AF, Gundabala VR, Hinder SJ, Keddie JL (2007) Lateral distribution of surfactants in waterborne pressure sensitive adhesive films: Theory and experiment, ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY 233 AMER CHEMICAL SOC
Hinder SJ, Grilli R, Rustame M, Baker MA, Santos WIA, Costa I (2014) A surface analytical investigation of cerium-based conversion coatings deposited onto an AA2024-T3 aluminium alloy cladding layer, Surface and Interface Analysis
Cerium-based conversion coatings are being investigated as alternatives to chromating treatments for the corrosion protection of aluminium and its alloys because of the environmentally unfriendly nature of the chromating process. This study investigates the surface film composition, structure and corrosion performance following a two-step surface treatment for an AA2024-T3 clad aluminium alloy. The two-step treatment comprised of an initial cerium conversion process involving immersion in an aqueous solution containing Ce ions at 75°C followed by immersion in a propylene glycol solution at 75°C. The coating surface morphology, composition and structure have been studied using SEM, XPS, Auger spectroscopy and Fourier transform infrared spectroscopy, while corrosion resistance was evaluated using electrochemical impedance spectroscopy. The coating formed by the two-step treatment is an interconnecting fibrous (pseudo) boehmite layer with the incorporation of Ce in the film. This two step treatment coating exhibits high impedance compared with the coatings formed through exposure to just stage 1 or stage 2 of the two-step treatment and shows good potential for improved corrosion protection. © 2014 John Wiley & Sons, Ltd.
Hinder SJ, Lowe C, Watts JF (2007) An XPS and ToF-SIMS investigation of the outermost nanometres of a poly(vinylidene difluoride) coating, PROGRESS IN ORGANIC COATINGS 60 (3) pp. 255-261 ELSEVIER SCIENCE SA
Rahna NB, Kalarivalappil V, Nageri M, Pillai SC, Hinder SJ, Kumar V, Vijayan BK (2016) Stability studies of PbS sensitised TiO2 nanotube arrays for visible light photocatalytic applications by X-ray photoelectron spectroscopy (XPS), MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING 42 pp. 303-310 ELSEVIER SCI LTD
Bailey MJ, Bright NJ, Croxton RS, Francese S, Ferguson LS, Hinder S, Jickells S, Jones BJ, Jones BN, Kazarian SG, Ojeda JJ, Webb RP, Wolstenholme R, Bleay S (2012) Chemical Characterization of Latent Fingerprints by Matrix-Assisted Laser Desorption Ionization, Time-of-Flight Secondary Ion Mass Spectrometry, Mega Electron Volt Secondary Mass Spectrometry, Gas Chromatography/Mass Spectrometry, X-ray Photoelectron Spectroscopy, and Attenuated Total Reflection Fourier Transform Infrared Spectroscopic Imaging: An Intercomparison., Anal Chem 84 (20) pp. 8514-8523 American Chemical Society
The first analytical intercomparison of fingerprint residue using equivalent samples of latent fingerprint residue and characterized by a suite of relevant techniques is presented. This work has never been undertaken, presumably due to the perishable nature of fingerprint residue, the lack of fingerprint standards, and the intradonor variability, which impacts sample reproducibility. For the first time, time-of-flight secondary ion mass spectrometry, high-energy secondary ion mass spectrometry, and X-ray photoelectron spectroscopy are used to target endogenous compounds in fingerprints and a method is presented for establishing their relative abundance in fingerprint residue. Comparison of the newer techniques with the more established gas chromatography/mass spectrometry and attenuated total reflection Fourier transform infrared spectroscopic imaging shows good agreement between the methods, with each method detecting repeatable differences between the donors, with the exception of matrix-assisted laser desorption ionization, for which quantitative analysis has not yet been established. We further comment on the sensitivity, selectivity, and practicability of each of the methods for use in future police casework or academic research.
Synnott DW, Seery MK, Hinder SJ, Michlits G, Pillai SC (2013) Anti-bacterial activity of indoor-light activated photocatalysts, Applied Catalysis B: Environmental 130-131 pp. 106-111
Nanocrystalline photocatalysts, prepared under ambient conditions using a microwave assisted synthesis, show indoor light photocatalytic activity for the degradation of Staphylococcus aureus and Escherichia coli. The zinc sulphide (ZnS) nanomaterials, prepared by a microwave assisted synthesis, are shown to be cubic blende structure with an average crystallite size of 4-6. nm. The anti-bacterial activity of these nanomaterials is investigated under irradiation from a 60. W light bulb and photocatalytic activity is revealed to be due to the defects present in the crystal structure. The ZnS shows anti-bacterial action as both a bacteriostatic and bacteriocidal (88% reduction in the amount of bacteria in 5. h) material and the methods of bacterial degradation on the ZnS is discussed. The anti-bacterial actions of these materials were also compared with commercial ZnS and Evonik-Degussa P-25. A detailed mechanism for the light absorption in the visible light region of the microwave prepared ZnS is proposed based on the luminescence spectroscopy. © 2012 Elsevier B.V.
Bright N, Webb RP, Hinder SJ, Kirkby KJ, Ward NI, Watts JF, Bleay S, Bailey M (2012) Determination of the deposition order of overlapping latent fingerprints and inks using Secondary Ion Mass Spectrometry (SIMS)., Anal Chem 84 (9) pp. 4083-4087 American Chemical Society
A new protocol using time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been developed to identify the deposition order of a fingerprint overlapping an ink line on paper. By taking line scans of fragment ions characteristic of the ink molecules (m/z 358.2 and 372.2) where the fingerprint and ink overlap and by calculating the normalised standard deviation of the intensity variation across the line scan, it is possible to determine whether or not a fingerprint is above ink on a paper substrate. The protocol adopted works for a selection of fingerprints from four donors tested here and for a fingerprint that was aged for six months; for one donor, the very faint fingerprints could not be visualized using either standard procedures (ninhydrin development) or SIMS and therefore the protocol correctly gives an inconclusive result.
Polychronopoulou K, Zedan A, Katsiotis M, Baker M, AlKhoori A, AlQaradawi S, Hinder S, AlHassan S (2017) Rapid Microwave Assisted Sol-Gel Synthesis of CeO2 and CexSm1-xO2 Nanoparticle Catalysts for CO Oxidation, Journal of Molecular Catalysis A: Chemical 428 pp. 41-55 Elsevier
CeO2 and CexSm1-xO2 nanoparticle mixed oxides have been synthesized by microwave assisted sol-gel (MW sol-gel) and conventional sol-gel (C sol-gel) synthesis carried out at 60oC (typical sol-gel) and 100oC (approaching the MW temperature). Different characterization techniques, namely, XRD, BET, Raman, SEM, FTIR, TEM, XPS, H2-TPR, CO2-TPD, and XPS have been employed to understand the process-structure-properties relationship of the catalysts. The CO oxidation performance has been determined both in the absence and in the presence of H2 in the feed gas stream. Microwave heating yields a more thermally stable precursor material, which preserves 75% of its mass up to 600oC, attributable to the different chemical nature of the precursor, compared to the typical sol-gel material with the same composition. Varying the synthesis method has no profound effect on the surface area of the materials, which is in the range 4-35m2/g. Conventional sol-gel synthesis performed at 60 and 100oC yields CeO2 particles with a crystallite size of 29 nm and 24 nm compared to 21-27 nm for MW sol-gel synthesis (at different power values). The MW sol-gel CexSm1-xO2 catalysts exhibit a smaller crystallite size (12-18 nm). The pure ceria nanoparticles were shown to have a stoichiometry of approximately CeO1.95. The presence of Ce3+ and Sm3+ in the mixed oxide particles facilitates the presence of oxygen vacant sites, confirmed by Raman. Oxygen mobile species have been traced using H2-TPR studies and a compressive lattice strain in the 0.45-1.9% range of the cubic CexSm1-xO2 lattice were found to be strongly correlated with the CO oxidation performance in the presence and absence of H2 in the oxidation feed stream. MW sol-gel synthesis led to more active CeO2 and Ce0.5Sm0.5O2 catalysts, demonstrated by T50 (temperature where 50% CO conversion is achieved), being reduced by 131 oC and 47 oC, respectively, compared to typical sol-gel catalysts. Conventional synthesis performed at 100oC leads to a CeO2 catalyst of initially higher activity at a certain temperature window (220-420oC), though with a slower increase of XCO with temperature compared to the MW one. MW sol-gel synthesized Ce0.8Sm0.2O2 exhibited a high performance (~90%) for CO oxidation over a period of more than 20 h in stream. In addition the effect of reaction temperature and contact time (W/F) on the activity of the CeO2-based materials for CO oxidation kinetics were investigated. The activation energy of the reaction was found to be in the 36-43 kJ/mole range depending on the catalyst composition.
Polychronopoulou K, Rebholz C, Baker MA, Theodorou L, Demas N, Hinder SJ, Polycarpou A, Doumanidis C, Boebel K (2008) Nanostructure, mechanical and tribological properties of reactive magnetron sputtered TiCx coatings, DIAMOND AND RELATED MATERIALS 17 (12) pp. 2054-2061 ELSEVIER SCIENCE SA
Charisiou N, Papageridis K, Siakavelas G, Tzounis L, Kousi K, Baker M, Hinder S, Cabeza V, Polychronopoulou K, Goula M (2017) Glycerol Steam Reforming for Hydrogen Production over Nickel Supported on Alumina, Zirconia and Silica Catalysts, Topics in Catalysis 60 (15-16) pp. 1226-1250 Springer Verlag
The aim of the work was to investigate the influence of support on the catalytic performance of Ni catalysts for the glycerol steam reforming reaction. Nickel catalysts (8 wt%) supported on Al2O3, ZrO2, SiO2 were prepared by the wet impregnation technique. The catalysts? surface and bulk properties, at their calcined, reduced and used forms, were determined by ICP, BET, XRD, NH3-TPD, CO2-TPD, TPR, XPS, TEM, TPO, Raman, SEM techniques. The Ni/Si sample, even if it was less active for T
Charisiou N.D., Tzounis L., Sebastian V., Hinder S.J., Baker M.A., Polychronopoulou K., Goula M.A. (2018) Investigating the correlation between deactivation and the carbon deposited on the surface of Ni/Al2O3 and Ni/La2O3-Al2O3 catalysts during the biogas reforming reaction, Applied Surface Science Elsevier
Ni/Al2O3 and Ni/La2O-Al2O3 catalysts were investigated for the biogas reforming reaction using CH4/CO2 mixtures with minimal dilution. Stability tests at various reaction temperatures were conducted and TGA/DTG, Raman, STEM-HAADF, HR-TEM, XPS techniques were used to characterize the spent samples. Graphitized carbon allotrope structures, carbon nanotubes (CNTs) and amorphous carbon were formed on all samples. Metallic Ni0 was recorded for all (XPS), whereas a strong peak corresponding to Ni2O3/NiAl2O4, was observed for the Ni/Al sample (650?750°C). Stability tests confirm that the Ni/LaAl catalyst deactivates at a more gradual rate and is more active and selective in comparison to the Ni/Al for all temperatures. The Ni/LaAl exhibits good durability in terms of conversion and selectivity, whereas the Ni/Al gradually loses its activity in CH4 and CO2 conversion, with a concomitant decrease of the H2 and CO yield. It can be concluded that doping Al2O3 with La2O3 stabilizes the catalyst by (a) maintaining the Ni0 phase during the reaction, due to higher dispersion and stronger active phase-support interactions, (b) leading to a less graphitic and more defective type of deposited carbon and (c) facilitating the deposited carbon gasification due to the enhanced CO2 adsorption on its increased surface basic sites.
Jurewicz Izabela, Garriga Rosa, Large Matthew J, Burn Jake, Bardi Niki, King Alice AK, Velliou Eirini, Watts John, Hinder Steven, Muñoz Edgar, Dalton Alan B (2018) Functionalization of Silver Nanowire Transparent Electrodes with Self-Assembled 2-Dimensional Tectomer Nanosheets, ACS Applied Nano Materials 1 (8) pp. 3903-3912 American Chemical Society
Here, we describe the unusual self-assembly of amine-terminated oligoglycine peptides into extended two-dimensional sheets in the presence of silver nanowires. The resulting tectomer sheets are shown to have a strong affinity for the nanowires through a charge-transfer interaction as evidenced by X-ray photoelectron spectroscopy. We show that extended assemblies of metal-peptide hybrids offer additional augmentative functionalities, for instance, the tectomer sheets are hydrophobic in nature and act as a protective layer preventing oxidation and degradation of the nanowires when exposed to atmospheric conditions. Moreover, for silver nanowire percolating networks the presence of the peptide markedly increases the overall electrical conductivity through mechanical squeezing of wire-wire junctions in the network. The peptide-metal interface can be controlled by pH stimulus thus potentially offering new directions where silver nanowire assemblies are used for transparent electrodes ranging from antimicrobial coatings to biosensors.
AlKetbi M., Polychronopoulou K., Zedan Abdallah. F., Sebastián V., Baker Mark A., AlKhoori A., Jaoude M.A., Alnuaimi O., Hinder Steve S., Tharalekshmy Anjana, AlJaber Amina S. (2018) Tuning the activity of Cu-containing rare earth oxide catalysts for CO oxidation reaction: Cooling while heating paradigm in microwave-assisted synthesis, Materials Research Bulletin 108 pp. 142-150 Elsevier
(Ce-La-xCu)O2 catalysts with low (3 at.%) and high (10 at.%) Cu content were prepared by conventional microwave (MW) and enhanced microwave methods where air cooling (AC), while heating, was applied. The catalysts were tested for the CO oxidation reaction in the 25?500 °C range using 4%CO/20%O2/He feed gas. Varying spectroscopic, microscopic and catalytic studies were used to probe the effect of synthesis on the nanostructure and the CO oxidation performance. It was found that the synthesis method adopted impacts on the extent of the Cu doping into the (Ce-La)O2 fluorite lattice, hence leading to one and two phases system in the case of catalyst prepared through enhanced (AC) and conventional (MW) microwave methods, respectively. Furthermore, only Ce4+ species were found on the surface of the (Ce-La-10Cu)O2 catalysts synthesized using MW and AC (XPS studies), whereas oxygen vacant sites which are associated with Ce3+ ions were indicated in the sub-surface/bulk (Raman studies). Ultimately, the catalysts with the low and high Cu loading, prepared under the AC-promoted microwave method, presented a superior performance against CO oxidation, exhibiting an overall improvement of the catalytic activity by 16% and 32%, respectively.
Zequine Camila, Bhoyate Sanket, Siam Khamis, Kahol Pawan K., Kostoglou Nikolaos, Mitterer Christian, Hinder Steven, Baker Mark, Constantinides Georgios, Rebholz Claus, Gupta Gautam, Li Xianglin, Gupta Ram K. (2018) Needle grass array of nanostructured nickel cobalt sulfide electrode for clean energy generation, Surface and Coatings Technology 354 pp. 306-312 Elsevier
Significant efforts have been focused on the search of earth-abundant elements to solve growing energy issues and to provide bifunctional behavior for both hydrogen and oxygen evolution reaction. Mixed transition metals could provide promising synergistic electrochemical properties and serve as bi-catalyst for overall water splitting process. In this study, a needle grass array of nanostructured nickel cobalt sulfide (NiCo2S4) was synthesized using a hydrothermal process. The synthesized NiCo2S4 electrodes showed promising electrocatalytic activity with a low overpotential of 148/mV and 293/mV for hydrogen and oxygen evolution reactions, respectively. The electrolyzer cell consisting of two NiCo2S4 electrodes displayed excellent performance with high electrochemical stability and low overall cell potential of 1.61/V to achieve a current density of 10/mA/cm2. Our study suggests that mixed transition metal chalcogenides such as NiCo2S4 could be used as efficient and stable electrocatalyst for overall water splitting process.
Charisiou N.D., Siakavelas G., Tzounis L., Sebastian V., Monzon A., Baker M.A., Hinder S.J., Polychronopoulou K., Yentekakis I.V., Goula M.A. (2018) An in depth investigation of deactivation through carbon formation during the biogas dry reforming reaction for Ni supported on modified with CeO2 and La2O3 zirconia catalysts, International Journal of Hydrogen Energy 43 (41) pp. 18955-18976 Elsevier
The dry reforming of biogas on a Ni catalyst supported on three commercially available materials (ZrO2, La2O3-ZrO2 and CeO2-ZrO2), has been investigated, paying particular attention to carbon deposition. The DRM efficiency of the catalysts was studied in the temperature range of 500-800oC at three distinct space velocities, and their time-on-stream stability at four temperatures (550, 650, 750 and 800oC) was determined for 10 or 50 h operation. The morphological, textural and other physicochemical characteristics of fresh and spent catalysts together with the amount and type of carbon deposited were examined by a number of techniques including BET-BJH method, CO2 and NH3-TPD, XPS, SEM, TEM, STEM-HAADF, Raman spectroscopy, and TGA/DTG. The impact of the La2O3 and CeO2 modifiers on the DRM performance and time-on-stream stability of the Ni/ZrO2 catalyst was found to be very beneficial: up to 20 and 30% enhancement in CH4 and CO2 conversions respectively, accompanied with a CO-enriched syngas product, while the 50 h time-on-stream catalytic performance deterioration of ~30-35% on Ni/ZrO2 was limited to less than ~15-20% on the La2O3 and CeO2 modified samples. Their influence on the amount and type of carbon formed was substantial: it was revealed that faster oxidation of the deposited carbon at elevated temperatures occurs on the modified catalysts. Correlations between the La2O3 and CeO2-induced modifications on the surface characteristics and physicochemical properties of the catalyst with their concomitant support-mediated effects on the overall DRM performance and carbon deposition were revealed.
Polychronopoulou Kyriaki, Charisiou Nikolaos D, Papageridis Kyriakos N, Sebastian Victor, Hinder Steven, Dabbawala Aasif A, AlKhoori Ayesha A., Baker Mark, Goula Maria A. (2018) The effect of Ni addition onto a Cu-based ternary support on the H‚ production over glycerol steam reforming reaction, Nanomaterials 8 (11) 931 pp. 1-27 MDPI
In the present study, Ni/Ce-Sm-xCu (x = 5, 7, 10 at.%) catalysts were prepared using microwave radiation coupled with sol-gel and followed by wetness impregnation method for the Ni incorporation. Highly dispersed nanocrystallites of CuO and NiO on the Ce-Sm-Cu support were found. Increase of Cu content seems to facilitate the reducibility of the catalyst according to the H‚ temperature-programmed reduction (H‚-TPR). All the catalysts had a variety of weak, medium and strong acid/basic sites that regulate the reaction products. All the catalysts had very high XC3H8O3 for the entire temperature (400?750 °C) range; from H84% at 400 °C to H94% at 750 °C. Ni/Ce-Sm-10Cu catalyst showed the lowest XC3H8O3-gas implying the Cu content has a detrimental effect on performance, especially between 450?650 °C. In terms of H‚ selectivity (SH2) and H‚ yield (YH2), both appeared to vary in the following order: Ni/Ce-Sm-10Cu à Ni/Ce-Sm-7Cu à Ni/Ce-Sm-5Cu, demonstrating the high impact of Cu content. Following stability tests, all the catalysts accumulated high amounts of carbon, following the order Ni/Ce-Sm-5Cu  Ni/Ce-Sm-7Cu  Ni/Ce-Sm-10Cu (52, 65 and 79 wt.%, respectively) based on the thermogravimetric analysis (TGA) studies. Raman studies showed that the incorporation of Cu in the support matrix controls the extent of carbon graphitization deposited during the reaction at hand.
Jenkins Peter, Yang Liu, Thomason James, Chen Xinyong, Watts John F, Hinder Steven J (2019) Investigation of Chemical and Physical Surface Changes of Thermally Conditioned Glass Fibres, Fibers 7 (1) MDPI
A number of analytical techniques were applied to investigate changes to the surface of unsized boron-free E-glass fibres after thermal conditioning at temperatures up to 700 °C. Novel systematic studies were carried out to investigate the fundamental strength loss from thermal conditioning. Surface chemical changes studied using X-ray photoelectron spectroscopy (XPS) showed a consistent increase in the surface concentration of calcium with increasing conditioning temperature, although this did not correlate well with a loss of fibre strength. Scanning electron microscopy fractography confirmed the difficulty of analysing failure-inducing flaws on individual fibre fracture surfaces. Analysis by atomic force microscopy (AFM) did not reveal any likely surface cracks or flaws of significant dimensions to cause failure: the observation of cracks before fibre fracture may not be possible when using this technique. Fibre surface roughness increased over the whole range of the conditioning temperatures investigated. Although surface roughness did not correlate precisely with fibre strength, there was a clear inverse relationship at temperatures exceeding 400 °C. The interpretation of the surface topography that formed between 400?700 °C produced evidence that the initial stage of phase separation by spinodal decomposition may have occurred at the fibre surface.
Zhang Chunyang, Bhoyate Sanket, Zhao Chen, Kahol Pawan, Kostoglou Nikolaos, Mitterer Christian, Hinder Steven, Baker Mark, Constantinides Georgios, Polychronopoulou Kyriaki, Rebholz Claus, Gupta Ram (2019) Electrodeposited Nanostructured CoFe2O4 for Overall Water Splitting and Supercapacitor Applications, Catalysts 9 (2)
To contribute to solving global energy problems, a multifunctional CoFe2O4 spinel was synthesized and used as a catalyst for overall water splitting and as an electrode material for supercapacitors. The ultra-fast one-step electrodeposition of CoFe2O4 over conducting substrates provides an economic pathway to high-performance energy devices. Electrodeposited CoFe2O4 on Ni-foam showed a low overpotential of 270 mV and a Tafel slope of 31 mV/dec. The results indicated a higher conductivity for electrodeposited compared with dip-coated CoFe2O4 with enhanced device performance. Moreover, bending and chronoamperometry studies suggest excellent durability of the catalytic electrode for long-term use. The energy storage behavior of CoFe2O4 showed high specific capacitance of 768 F/g at a current density of 0.5 A/g and maintained about 80% retention after 10,000 cycles. These results demonstrate the competitiveness and multifunctional applicability of the CoFe2O4 spinel to be used for energy generation and storage devices.
Charisiou N.D., Siakavelas G., Tzounis L., Dou B., Sebastian V., Hinder S.J., Baker M.A., Polychronopoulou K., Goula M.A. (2019) Ni/Y‚Oƒ?ZrO‚ catalyst for hydrogen production through the glycerol steam reforming reaction, International Journal of Hydrogen Energy Elsevier
In the study presented herein, the catalytic activity and stability of a Ni catalyst supported on Y2O3?ZrO2 was examined for the first time in the glycerol steam reforming reaction and compared with a Ni/ZrO2. The addition of Y2O3 stabilized the ZrO2 tetragonal phase, increased the O2 storage capacity of the support and the medium strength acid sites of the catalyst, and although the Ni/Zr catalyst had a higher concentration of basic sites, the Ni/YZr presented more stable monodentate carbonates. Moreover, the Ni/YZr had substantially higher Ni surface concentration and smaller Ni particles. These properties influence the gaseous products? distribution by increasing the H2 yield and selectivity and preventing the transformation of CO2 to CO, by inhibiting the reverse water gas shift (RWGS) reaction from taking place. For both catalysts the main liquid products identified were allyl alcohol, acetaldehyde, acetone, acrolein, acetic acid and acetol; these were subsequently quantified. The time-on-stream experiments showed that the Ni/YZr was more stable during reaction and had a higher H2 yield after 20 h (2.17 in comparison to 1.50 mol H2/mol C3H8O3, for the Ni/Zr). Extensive investigation of the carbon deposits showed that although lower amounts of coke were deposited on the Ni/Zr catalyst, these structures were more graphitic in nature and had fewer defects, which means they were harder to oxidize. Moreover, transmission electron microscopy (TEM) analysis showed that sintering of Ni nanoparticles during the reaction was significant for the Ni/Zr catalyst, as the mean particle diameter increased from an initial value of 48.2 to 67.9 nm, while it was almost absent on the Ni/YZr catalyst (the mean particle diameter increased from 42.1 to 47.4 nm).
Charisiou Nikolaos D., Siakavelas Georgios I., Dou Binlin, Sebastian Victor, Hinder Steven, Baker Mark, Polychronopoulou Kyriaki, Goula Maria A. (2019) Nickel Supported on AlCeO3 as a Highly Selective and Stable Catalyst for Hydrogen Production via the Glycerol Steam Reforming Reaction, Catalysts 9 (5)
In this study, a critical comparison between two low metal (Ni) loading catalysts is presented, namely Ni/Al2O3 and Ni/AlCeO3 for the glycerol steam reforming (GSR) reaction. The surface and bulk properties of the catalysts were evaluated using a plethora of techniques, such as N2 adsorption/desorption, ICP-AES, XRD, XPS, SEM/EDX, TEM, CO2-TPD, NH3-TPD, H2-TPR. Carbon deposited on the catalysts surfaces was probed using TPO, SEM and TEM. It is demonstrated that Ce-modification of Al2O3 induces an increase of the surface basicity and Ni dispersion. These features lead to a higher conversion of glycerol to gaseous products (60% to 80%), particularly H2 and CO2, enhancement of WGS reaction and a higher resistance to coke deposition. Allyl alcohol was found to be the main liquid product for the Ni/AlCeO3 catalyst, the production of which ceases over 700 oC. It is also highly significant that the Ni/AlCeO3 catalyst demonstrated stable values for H2 yield (2.9-2.3) and selectivity (89-81%), in addition to CO2 (75-67%) and CO (23-29%) selectivity during a (20h) long time-on-stream study. Following the reaction, SEM/EDX and TEM analysis showed heavy coke deposition over the Ni/Al2O3 catalyst, whereas for the Ni/AlCeO3 catalyst TPO studies showed the formation of more defective coke, the latter being more easily oxidized
Zhao Chen, Zhang Chunyang, Bhoyate Sanket, Kahol Pawan, Kostoglou Nikolaos, Mitterer Christian, Hinder Steven, Baker Mark, Constantinides Georgios, Polychronopoulou Kyriaki, Rebholz Claus, Gupta Ram (2019) Nanostructured Fe-Ni Sulfide: A Multifunctional Material for Energy Generation and Storage, Catalysts MDPI AG
Al Ketbi Maitha, Polychronopoulou Kyriaki, Abi Jaoude Maguy, Vasiliades Michalis A, Sebastian Victor, Hinder Steven J, Baker Mark A, Zedan Abdallah F, Efstathiou Angelos M (2019) Cu-Ce-La-Ox as efficient CO oxidation catalysts: effect of Cu content, Applied Surface Science Elsevier
Nanograins of Ce-La-xCu-O oxides, of 16 nm2 area size, are
tested as materials towards the CO oxidation . Preservation of the cubic
lattice structure following La3+ and Cu2+ metal cations doping is
confirmed based on the powder X-ray diffraction and Raman studies. From
XPS, the presence of mixed Ce3+/Ce4+ and Cu2+/Cu1+ oxidation states was
confirmed, which was more profound in the low Cu-content Ce-La-xCu-O
catalysts. Cu increases the concentration of oxygen vacant sites in the
doped-CeO2 according to the Raman intensity ratio IOv/IF2g of 1.58 and
1.78 with the increase in copper content from 7 to 20 at.% as compared
to the lower value of 0.44 for the Ce-La. The mobility of the surface
and bulk lattice oxygen is further investigated using 16O/18O isotopic
exchange (TIIE), and is found to be Cu at.% dependent. For the case of
Ce-La-20Cu, the participation of the lattice oxygen (OL) in the reaction
mechanism has been demonstrated using transient experiments.
Accordingly, the specific rate (¼mol CO m-2s-1) of the CO oxidation
reaction is found to be higher for the Ce-La-20Cu and Ce-La-7Cu
catalysts, corroborating thus the presence of more mobile/labile oxygen
species in those ternary catalysts as opposed to the other lower copper
compositions.
Jaoude M. Abi, Alhseinat Emad, Polychronopoulou K., Bharath G., Darawsheh Ismail Farouq Fahmi, Anwer Shoaib, Baker Mark A., Hinder Steven J., Banat Fawzi (2020) Morphology-dependent electrochemical performance of MnO‚ nanostructures on graphene towards efficient capacitive deionization, Electrochimica Acta 330 135202 Elsevier
Capacitive deionization (CDI) is an emerging desalination technology that still needs further development to enhance its performance for practical implementation. Herein, we present a hybrid CDI approach, which integrates the electrical double-layer (EDL) with the sodium-ion battery concept to improve the separation of sodium and chloride ions from saline water. The hybrid CDI cell is achieved by using hydrothermally-grown and uniformly dispersed prawn-like ±-MnO‚/graphene (±-MnO‚/G) nanocomposite as anode material, and graphene at the cathode. In this paper, the effect of MnO‚ morphology on the electrode electrochemical performance and its effect on capacitive deionization performance have been fully investigated. In this configuration, the Naz ions are inserted by the electrochemical reaction at the ±-MnO‚/G electrode, whereas Cl{ ions are captured by the graphene-based electrode. The morphological dependent electrochemical properties of the obtained nanocomposites were studied deeply through CV and EIS analysis. The established hybrid CID cell provides an electrical capacitance as high as 375/F/g{¹ at 10/mV/s{¹, cation-selectivity, good electrical stability and low internal resistance. The hybrid CDI device also shows a stable and reversible salt insertion/de-insertion capacity up to 29.5/mg/g{¹ at 1.2/V. These results demonstrate the suitability of prawn-like ±-MnO‚/G nanocomposite to produce high-performance hybrid CDI cells.
Li Bowei, Xiang Yuren, Jayawardena Imalka, Luo Deying, Watts John, Hinder Steven, Li Hui, Ferguson Victoria, Luo Haitian, Zhu Rui, Silva Ravi, Zhang Wei (2020) Tailoring Perovskite Adjacent Interfaces by Conjugated Polyelectrolyte for Stable and Efficient Solar Cells, Solar RRL Wiley-Blackwell
Interface engineering is an effective means to enhance the performance of thin?film devices, such as perovskite solar cells (PSCs). Herein, a conjugated polyelectrolyte, poly[(9,9?bis(32?((N,N?dimethyl)?N?ethyl?ammonium)?propyl)?2,7?fluorene)?alt?2,7?(9,9?dioctylfluorene)]di?iodide (PFN?I), is used at the interfaces between the hole transport layer (HTL)/perovskite and perovskite/electron transport layer simultaneously, to enhance the device power conversion efficiency (PCE) and stability. The fabricated PSCs with an inverted planar heterojunction structure show improved open?circuit voltage (Voc), short?circuit current density (Jsc), and fill factor, resulting in PCEs up to 20.56%. The devices maintain over 80% of their initial PCEs after 800 h of exposure to a relative humidity 35?55% at room temperature. All of these improvements are attributed to the functional PFN?I layers as they provide favorable interface contact and defect reduction.