Photocatalytic reduction of CO2 with H2O over a graphene-modified NiOx-Ta2O5 composite photocatalyst: coupling yields of methanol and hydrogen

A reduced graphene modified Ta2O5 photocatalyst (Ta2O5-rG) was prepared using a one-step hydrothermal method, and the photocatalytic reduction of an aqueous CO2 solution to CH3OH and H-2 using the NiOx-Ta2O5-rG photocatalyst was performed. Due to graphene's electron transfer and collecting characteristics, reduced graphene was found to be important in achieving high methanol yields for this multi-electron reduction process. The NiOx-Ta2O5-rG photocatalyst also showed good production selectivity for the competing reactions of CH3OH and H-2 generation in aqueous CO2 or CO2/NaHCO3 solution.