LAUSR

To solve the increasing level of carbon dioxide (CO2) in the atmosphere, bismuth vanadate (BiVO4) based photoanode for photoelectrochemical water oxidation has been considered as a promising candidate of power supply for CO2 reduction because of its low price and relatively narrow bandgap. Nevertheless, the PEC capability of BiVO4 photoelectrode is restricted by the short carrier diffusion length, undesirable electron transport ability, and slow oxygen evolution rate. To conquer these shortages, we design and fabricate a novel ternary hybrid composite of 3D Co-Pi/BiVO4/SnO2 nanosheet array photoanode. Benefiting from the high light harvesting ability of nanosheet arrays, effective separation of electron-hole pairs for BiVO4/SnO2 heterojunction and fast water oxidation rate of Co-Pi, the hybrid system behaved a 20.2-times enhancement in photocurrent and a significant cathodic shift about the onset potential of water oxidation reaction compared with single BiVO4. Coupled with Au nanoparticle cathode, the PEC cell exhibited a 90.0% faradaic efficiency for CO2 reduction under a small applied voltage of 1.10 V and saved more than 50% of electric-energy compared to the general electrochemical (EC) cell. We believe that the fabricated 3D Co-Pi/BiVO4/SnO2 NSAs with remarkably enhanced PEC performance could provide clean power for modern society via a reduction reaction on pollution gases.