The team uses a nanostructured n-type ZnO coating on p-type silicon to enhance light absorption and charge separation/transfer, thus improving the surface kinetics for H2 evolution. Also, the metal nano-coating further catalyses the redox reaction and prevents corrosion.

Ongoing research involves exploiting other metal oxide nanowire coatings with smaller band gaps or improved chemical/electrochemical robustness on planar silicon, black silicon and/or silicon nanowire arrays (such as 3D nanowire heterostructures or “nanotrees”) to further increase energy conversion efficiency and make solar hydrogen production more practical.

Additional information can be found in the journal Nanotechnology.