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

Abstract

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 H₂ using the NiO_x–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 NiO_x–Ta₂O₅–rG photocatalyst also showed good production selectivity for the competing reactions of CH₃OH and H₂ generation in aqueous CO₂ or CO₂/NaHCO₃ solution.