Dual-metal sites CuInS2/g-C3N4 Z-scheme heterojunction with efficient photocatalytic CO2 reduction selectivity

The application of solar energy to transform carbon dioxide into energy-rich products is one of the sustainable ways to alleviate energy scarcity and environmental crisis. However, the low efficiency of solar light and the high recombination of photogenerated electron-hole pairs limit the industrial value of photocatalytic technology in terms of applications. Here, we report a high-performance photocatalyst based on g-C3N4, which was compounded and modified utilizing CuInS2. The photocatalytic performance is enhanced by constructing Z-scheme heterojunction for efficient separation and transfer of photogenerated carriers to meet the practical application requirements. CuInS2/g-C3N4 has the best photocatalytic CO yield of 246.75 μmol/g/h and CO selectivity of more than 93%. The role of dual-metal sites in the catalytic system is also explored by DFT calculations. The results not only provide a new perspective for the design of efficient CO2 photoreduction photocatalysts, but also provide a proven method for enhancing the performance of photocatalysts.