Regulating the Metallic Cu–Ga Bond by S Vacancy for Improved Photocatalytic CO<sub>2</sub> Reduction to C<sub>2</sub>H<sub>4</sub>
Junyan Wang, Chen Yang, Liang Mao, Xiaoyan Cai, Zikang Geng, Haoyu Zhang, Junying Zhang, Xin Tan, Jinhua Ye, Tao Yu
Abstract
Abstract Artificial photosynthesis, which converts carbon dioxide into hydrocarbon fuels, is a promising strategy to overcome both global warming and energy crisis. Herein, the geometric position of Cu and Ga on ultra‐thin CuGaS 2 /Ga 2 S 3 is oriented via a sulfur defect engineering, and the unprecedented C 2 H 4 yield selectivity is ≈93.87% and yield is ≈335.67 µmol g −1 h −1 . A highly delocalized electron distribution intensity induced by S vacancy indicates that Cu and Ga adjacent to S vacancy form Cu–Ga metallic bond, which accelerates the photocatalytic reduction of CO 2 to C 2 H 4 . The stability of the crucial intermediates (*CHOHCO) is attributed to the upshift of the d ‐band center of ultra‐thin CGS/GS. The C–C coupling barrier is intrinsically reduced by the dominant exposed Cu atoms on the 2D ultra‐thin CuGaS 2 /Ga 2 S 3 in the process of photocatalytic CO 2 reduction, which captures *CO molecules effectively. This study proposes a new strategy to design photocatalyst through defect engineering to adjust the selectivity of photocatalytic CO 2 reduction.