One-step photodeposition of spatially separated CuOx and MnOx dual cocatalysts on g-C3N4 for enhanced CO2 photoreduction

Abstract

Abstract Photocatalytic CO2 conversion into valuable chemicals has been proved to be a promising strategy for relieving energy shortage and environmental pollution. Nevertheless, the rapid recombination of photogenerated carriers of photocatalyst greatly limits their actual application. In this work, dual CuOx and MnOx cocatalysts are decorated on g-C3N4 nanosheets via a one-step photodeposition strategy. Benefiting from the repulsion between Cu2+ and Mn2+ cations, a novel g-C3N4-based heterostructure loaded with spatially separated CuOx nanoparticles and MnOx nanosheets dual cocatalysts has been successfully fabricated. The Cu favors the trapping of electrons, while MnOx tends to collect holes. Moreover, the Cu2O/g-C3N4 p-n heterojunction also accelerates the charge separation. As a result, the photogenerated holes and electrons flow into and out of the photocatalyst, respectively, resulting in enhanced charge separation for achieving efficient CO2 photoreduction over CuOx/g-C3N4/MnOx. Impressively, the optimized CuOx/g-C3N4/MnOx exhibits an improved CO production rate of 5.49 µmol g− 1 h− 1, which exceeds over 27.5 times than bare g-C3N4. This work designs a promising photocatalyst for CO2 photoreduction and develops a novel one-step photodeposition route for decorating spatially separated dual cocatalysts on a photocatalyst.