Z-Scheme Cu2O/Cu/Cu3V2O7(OH)2·2H2O Heterostructures for Efficient Visible-Light Photocatalytic CO2 Reduction

Developing Z-scheme heterojunction photocatalysts has been regarded as a feasible approach to enhance the charge carrier lifetimes without reducing their redox potentials. In this work, a Z-scheme Cu 3 V 2 O 7 (OH) 2 ·2H 2 O/Cu/Cu 2 O (denoted as CVO/Cu/Cu 2 O) heterojunction was successfully fabricated for the first time and used as photocatalysts for CO 2 reduction. It was demonstrated that successively loading metallic Cu and Cu 2 O nanoparticles (NPs) on the surface of CVO could significantly improve the photocatalytic performance of CVO, and the highest CO evolution rate of 6.97 μmol·g –1 ·h –1 was obtained over the optimized CVO/Cu/Cu 2 O, which was 25.6 and 2.3 times higher than those of CVO and CVO/Cu 2 O, respectively. Moreover, CVO/Cu/Cu 2 O maintained a high stability even after five cycle reactions as compared to the binary CVO/Cu 2 O. The improved photocatalytic performance of CVO/Cu/Cu 2 O was mainly attributed to the enhanced visible-light absorption capability and the efficient Z-Scheme heterojunctions, which would boost the generation, migration, and separation of photogenerated charge carriers. This work may provide a strategy to design and fabricate copper vanadate-based Z-scheme heterojunction photocatalysts with high efficiency for CO 2 reduction.