Reversed Electron Transfer in Cu‐TiO <sub>2</sub> @ZnIn <sub>2</sub> S <sub>4</sub> for Boosting Photocatalytic CO <sub>2</sub> Reduction
Chen Zhao, Awu Zhou, Hanbing Li, Jiamei Yu, Na Xing, Jianyu Zhang, Dayu Chen, Jian‐Rong Li
Abstract
Abstract Spontaneous free‐electron transfer significantly affects the photocatalytic performance of carbon dioxide (CO 2 ) reduction. However, the precise regulation of photogenerated electron transfer direction remains a nontrivial endeavor. Herein, a heteroatomic metal‐dependent strategy is proposed to direct photogenerated electron transfer to specific catalytic active sites, thus enhancing CO 2 photoreduction over Cu‐TiO 2 @ZnIn 2 S 4 (Cu‐TiO 2 @ZIS). The core‐shell Cu‐TiO 2 @ZIS heterojunction with high activity is fabricated by in situ growth. Impressively, the optimized Cu‐TiO 2 @ZIS photocatalyst exhibits a remarkable visible light driven CO 2 ‐to‐carbon monoxide (CO) production rate of 620 µmol g −1 h −1 with selectivity (99.4%), representing a 77.5‐fold and 6.3‐fold enhancement over pristine TiO 2 (8 µmol g −1 h −1 ) and ZIS (99 µmol g −1 h −1 ), respectively. In situ characterization and theoretical calculations reveal that the combination of Cu‐TiO 2 and ZnIn 2 S 4 forms a strong interface electric field and regulates the direction of electron transfer due to the work function difference. Cu sites induce the transfer of photogenerated electrons from ZIS to Cu‐TiO 2 to generate electron‐rich Cu/Ti active sites, increasing the adsorption energy of CO 2 on Cu/Ti sites. Moreover, Cu‐TiO 2 @ZIS significantly reduces Gibbs free energy barriers for *COOH intermediate formation, thereby enhancing the photocatalytic performance of CO 2 reduction. This work exemplifies a new strategy for designing high‐active photocatalysts by manipulating heteroatomic metal‐dependent electron transfer.