Combining CoAl-LDH nanosheets with Bi19S27Br3 nanorods to construct a Z-scheme heterojunction for enhancing CO2 photoreduction

In this study, a novel Z-scheme Bi19S27Br3/CoAl-LDH heterojunction was prepared. An interface charge transfer channel was established between Bi19S27Br3 and CoAl-LDH, accelerating the transition efficiency of interface electrons from CoAl-LDH to Bi19S27Br3. Thereby ensuring more excited electrons to participate in CO2 photoreduction reactions. The reduction products were tested under artificial light conditions, and triethanolamine was selected as a sacrificial agent. After 5 h of illumination, the CO yield of Bi19S27Br3/CoAl-LDH Z-scheme heterojunction was 86.41 μmol·g−1 is 4 times and 7 times higher than Bi19S27Br3 and CoAl-LDH, respectively. The yield of CH4 in Bi19S27Br3/CoAl-LDH is 3.97 μmol·g−1 is 4 times higher than CoAl-LDH. Also Bi19S27Br3 itself does not produce CH4. The results indicate that the Z-scheme heterojunction effectively enhances the photoreduction ability of CO2, providing a new approach for accurately controlling the direction of photo generated charge separation to prepare high-performance photocatalysts.