Engineering Cu₂O Nanowire Surfaces for Photoelectrochemical Hydrogen Evolution Reaction

Cu2O is a narrow band gap material serving as an important candidate for photoelectrochemical hydrogen evolution reaction. However, the main challenge that hinders its practical exploitation poor photostability, due to oxidation into CuO by photoexcited holes. Here, we thoroughly minimize photo-oxidation of nanowires growing thin layer TiO2 protective and amorphous VOx cocatalyst using magnetron sputtering atomic deposition, respectively. After optimization layers, photoelectrode exhibits current density −2.46 mA/cm2 under simulated sunlight (100 mW/cm2) at 0.3 V versus reversible electrode, performance stable extended illumination time. The chemical stability good engineered demonstrate potential earth-abundant materials light-harvesting device solar production.