InVO/β-AgVO Nanocomposite as a Direct Z-Scheme Photocatalyst toward Efficient and Selective Visible-Light-Driven CO Reduction.

Photocatalytic CO reduction to solar fuel is a promising route to alleviate the ever-growing energy crisis and global warming. Herein, to enhance photoconversion efficiency of CO reduction, a series of direct Z-scheme composites consisting of β-AgVO nanoribbons and InVO nanoparticles (InVO/β-AgVO) are prepared via a facile hydrothermal method and subsequent in situ growth process. The prepared InVO/β-AgVO composites exhibit enhanced photocatalytic activity for reduction of CO to CO under visible-light illumination. A CO evolution rate of 12.61 μmol·g·h is achieved over the optimized 20% In-Ag without any cocatalyst or sacrificial agent, which is 11 times larger than that yielded by pure InVO (1.12 μmol·g·h). Moreover, the CO selectivity is more than 93% over H production from the side reaction of HO reduction. Significantly, based on the results of electron spin resonance (ESR) and in situ irradiated XPS tests, it is proposed that the synthesized InVO/β-AgVO catalysts comply with the direct Z-scheme transfer mechanism. Significantly improved photocatalytic activities for selective CO reduction could be primarily ascribed to effective separation of photoinduced electron-hole pairs and enhanced reducibility of photoelectrons at the conduction band of InVO. This work provides a new insight for constructing highly efficient photocatalytic CO reduction systems toward solar fuel generation.