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

Abstract

Developing Z-scheme heterojunction photocatalysts has\nbeen regarded\nas a feasible approach to enhance the charge carrier lifetimes without\nreducing their redox potentials. In this work, a Z-scheme Cu₃V₂O₇(OH)₂·2H₂O/Cu/Cu₂O (denoted as CVO/Cu/Cu₂O) heterojunction was successfully\nfabricated for the first time and used as photocatalysts for CO₂ reduction. It was demonstrated that successively loading\nmetallic Cu and Cu₂O nanoparticles (NPs) on the surface\nof CVO could significantly improve the photocatalytic performance\nof CVO, and the highest CO evolution rate of 6.97 μmol·g^–1·h^–1 was obtained over the\noptimized CVO/Cu/Cu₂O, which was 25.6 and 2.3 times higher\nthan those of CVO and CVO/Cu₂O, respectively. Moreover,\nCVO/Cu/Cu₂O maintained a high stability even after five\ncycle reactions as compared to the binary CVO/Cu₂O. The\nimproved photocatalytic performance of CVO/Cu/Cu₂O was\nmainly attributed to the enhanced visible-light absorption capability\nand the efficient Z-Scheme heterojunctions, which would boost the\ngeneration, migration, and separation of photogenerated charge carriers.\nThis work may provide a strategy to design and fabricate copper vanadate-based\nZ-scheme heterojunction photocatalysts with high efficiency for CO₂ reduction.