Hierarchical V2O5/ZnV2O6 nanosheets photocatalyst for CO2 reduction to solar fuels

Abstract The photocatalytic conversion of CO2 to chemical fuel is an important part of artificial photosynthesis, and a promising solution to utilize solar energy for sustainable energy generation. In this study, V2O5/ZnV2O6 nanosheet heterojunctions were in-situ synthesized using a hydrothermal method followed by calcination. The in-situ preparation is expected to generate intimate interfaces between these two materials, which can maximize the charge transfer and separation efficiency. Our results showed that V2O5/ZnV2O6 nanocomposites prepared at calcination temperature of 400 °C exhibits the most enhancement in electrochemical properties (photocurrent, EIS, etc), which results in 2.2 and 1.9 times improvement in the CO production rate from CO2 photoreduction as compared to V2O5 and ZnV2O6, respectively. The enhanced photocatalytic property is also supported from the theoretical calculation, showing charge transfer at the interface from ZnV2O6 to V2O5, enhanced CO2 adsorption at the V2O5/ZnV2O6 surface, and preferred CO product selectivity. This work indicated that the Vanadium-based close-contacted heterojunctions can be a promising photocatalysts in the environmental and energy applications.