Development of a photoelectrochemically self-improving Si/GaN photocathode for efficient and durable H2 production

Development of an efficient yet durable photoelectrode is paramount importance for deployment solar-fuel production. Here, we report the photoelectrochemically self-improving behaviour a silicon/gallium nitride photocathode active hydrogen production with Faradaic efficiency approaching ~100%. By using correlative approach based on different spectroscopic and microscopic techniques, as well density functional theory calculations, provide mechanistic understanding chemical transformation that origin behaviour. A thin layer gallium oxynitride forms side walls grains, via partial oxygen substitution at nitrogen sites, displays higher catalytic sites hydrogen-evolving reaction. This work demonstrates into leads to sustained operation enhanced activity, thus showing promise layers protective coatings evolution. photoelectrodes The highly now reported.