Z-Scheme Heterojunction CdIn2S4/BiVO4 with a Spherical Structure for Photocatalytic CO2 Reduction

Z-scheme heterojunction photocatalysts are at the forefront of carbon dioxide reduction research. However, BiVO 4 faces challenges due to its inappropriate conduction band position and rapid charge carrier recombination. In this article, spherical CdIn 2 S 4 /BiVO 4 Z-scheme heterojunction composites attached to coiled nanosheets were synthesized via a hydrothermal method, which improved the CO 2 reduction efficiency and addressed these limitations. The morphology, crystal structure, band structure, and photoelectrochemical properties of the sample were further studied. The CdIn 2 S 4 /BiVO 4 composites exhibit superior photocatalytic activity compared to pure CdIn 2 S 4 and BiVO 4, with the CdIn 2 S 4 /BiVO 4 composite containing 25% BiVO 4 yielding the highest CO and CH 4 production rates of 4.51 μmol g –1 h –1 and 1.01 μmol g –1 h –1, respectively, after 6 h and achieving an 81.7% CO selectivity. The Z-scheme design effectively mitigates charge recombination, boosts electron transfer, and enhances the photocatalytic CO 2 activity. The mechanism of photogenerated carrier transfer in catalysts was elucidated through density functional theory. This work offers insights and theories into the design and preparation of BiVO 4 -based heterojunction photocatalysts.