Enhanced photocatalytic activity and mechanism insight of copper-modulated lead-free Cs2AgSbCl6 double perovskite microcrystals
Daofu Wu, Xiaoqing Liu, Changqing Tian, Jinchen Zhou, Jun’an Lai, Hongmei Ran, Bo Gao, Miao Zhou, Qiang Huang, Xiaosheng Tang
Abstract
Lead halide perovskites are prospective candidates for CO 2 photoconversion. Herein, we report copper-doped lead-free Cs 2 AgSbCl 6 double perovskite microcrystals (MCs) for gas-solid phase photocatalytic CO 2 reduction. The 0.2Cu@Cs 2 AgSbCl 6 double perovskite MCs display unprecedented CO 2 photoreduction capability with CO and CH 4 yields of 412 and 128 μmol g −1 , respectively. The ultrafast transient absorption spectroscopy reveals the enhanced separation of photoexcited carriers in copper-doped Cs 2 AgSbCl 6 MCs. The active sites and reaction intermediates on the surface of the doped Cs 2 AgSbCl 6 are dynamically monitored and precisely unraveled based on the in-situ Fourier transform infrared spectroscopy investigation. In combination with density functional theory calculations, it is revealed that the copper-doped Cs 2 AgSbCl 6 MCs facilitate sturdy CO 2 adsorption and activation and strikingly enhance the photocatalytic performance. This work offers an in-depth interpretation of the photocatalytic mechanism of Cs 2 AgSbCl 6 doped with copper, which may provide guidance for future design of high-performance photocatalysts for solar fuel production.