‘Walking’ water discovery on 2D material could lead to better anti-icing coatings and energy materials

In a study published in Nature Communications, researchers from the University of Surrey and Graz University of Technology tested two ultra-thin, sheet-like materials with a honeycomb structure – graphene and hexagonal boron nitride (h-BN). While graphene is electrically conductive – making it a key contender for future electronics, sensors and batteries – h-BN, often called ‘white graphite’, is a high-performance ceramic material and electrical insulator. 

Researchers found that this subtle difference completely changes how water interacts with the surfaces. Instead of jumping between fixed points as it does on graphene, individual water molecules on h-BN move in a smooth, rolling motion – almost like it is walking across. 

This unexpected behaviour shows how even the smallest variations in a material’s atomic structure can dramatically alter how water moves at the nanoscale, offering scientists new insights for designing surfaces that control friction, wetting and ice formation. 

To capture the movement, the Graz team used a highly sensitive technique called helium spin-echo spectroscopy, which can track the motion of individual molecules without disturbing them. Researchers at Surrey also ran advanced computer simulations to model what was happening at the atomic level. 

Together, the experiments and simulations showed that water experiences less friction on h-BN – particularly when the material is supported by nickel – allowing the molecule to move more freely. On graphene, by contrast, the underlying metal strengthens the interaction between the molecule and the surface, increasing friction and making movement less smooth.