Tuning band gap energy of CuxInyS for superior photothermocatalytic CO2 conversion to C2H4

Photothermal synergistic catalysis significantly enhances the efficiency of photocatalytic CO2 reduction, offering a promising strategy for accelerated CO2 resource utilization. Herein, a series of CuxInyS photocatalysts were synthesized, exhibiting tunable band gap energy by varying the Cu/In/S atomic ratios for photothermocatalytic CO2 conversion to C2H4. The typical CuInS2 demonstrates a more negative conduction band, significantly enhancing electron reduction ability and facilitating the multi-electron reduction of CO2 to C2H4. Additionally, the high sulfur vacancy in CuInS2 generates additional active sites, enhances charge separation efficiency, and consequently improves catalytic activity. The generation rate of ethylene reaches 45.7 μmol·g-1·h-1 with the selectivity of 79.7%. This study provides a new avenue for producing ethylene in photothermal catalysis, as well as highlights the superiorities of CuInS2 catalyst.