Yuheng Liu

Porous carbon spheres represent an ideal family of electrode materials for supercapacitors because of the high surface area, ideal conductivity, negligible aggregation, and ability to achieve space efficient packing. However, the development of new synthetic methods towards porous carbon spheres still remains a great challenge. Herein, N-doped hollow carbon spheres with an ultrahigh surface area of 2044 m²/g have been designed based on the phenylenediamine-formaldehyde chemistry. When applied in symmetric supercapacitors with ionic electrolyte (EMIBF4), the obtained N-doped hollow carbon spheres demonstrate a high capacitance of 234 F/g, affording an ultrahigh energy density of 114.8 Wh/kg. Excellent cycling stability has also been achieved. The impressive capacitive performances make the phenylenediamine-formaldehyde resin derived N-doped carbon a promising candidate electrode material for supercapacitors.

Carbon-supported transition metal catalysts have attracted intense interest for oxygen reduction reaction (ORR) due to their high activity and low cost. Herein, we report bimetallic zeolitic imidazole frameworks (BMZIF)-derived hierarchical N-doped carbon spheres anchored with graphene-encapsulated Co nanocrystals ([email protected]) and spatially isolated single Co atoms (Co SAs) (denoted as Co-NCS) for highly efficient ORR. An ultrasonic strategy has been developed to uniformly anchor BMZIF on resin microspheres. The ultrasonic method significantly shortens the synthesis time and contributes to the homogeneous distribution of BMZIF. The inner resin spheres act as ideal support to anchor Zn/Co ions and prevent the aggregation of BMZIF nanocrystals, and the derived products provide adequate structural support and high conductivity after carbonization. Meanwhile, the outer BMZIF-derived porous carbon framework provides large specific surface area, promoted electron transport, and abundant exposed active sites. The co-existence of Co SAs and [email protected] plays a vital role in the ORR process. The resultant catalyst demonstrates superior ORR performance with a half-wave potential (J1/2) of 0.90 V, outperforming the commercial Pt/C. This work opens a new path to construct efficient Co-N-C based catalysts.

Thermal spray coatings have the advantage of providing thick and functional coatings from a range of engineering materials. The associated coating processes provide good control of coating thickness, morphology, microstructure, pore size and porosity, and residual strain in the coatings through selection of suitable process parameters for any coating material of interest. This review consolidates scarce literature on thermally sprayed components which are critical and vital constituents (e.g., catalysts (anode/cathode), solid electrolyte, and transport layer, including corrosion‐prone parts such as bipolar plates) of the water splitting electrolysis process for hydrogen production. The research shows that there is a gap in thermally sprayed feedstock material selection strategy as well as in addressing modelling needs that can be crucial to advancing applications exploiting their catalytic and corrosion‐resistant properties to split water for hydrogen production. Due to readily scalable production enabled by thermal spray techniques, this manufacturing route bears potential to dominate the sustainable electrolyser technologies in the future. While the well‐established thermal spray coating variants may have certain limitations in the manner they are currently practiced, deployment of both conventional and novel thermal spray approaches (suspension, solution, hybrid) is clearly promising for targeted development of electrolysers.