In Situ Loading of Cu Nanocrystals on CsCuCl<sub>3</sub> for Selective Photoreduction of CO<sub>2</sub> to CH<sub>4</sub>
Hai‐Bing Zhao, Jia‐Nan Huang, Qi Qin, Hong‐Yan Chen, Dai‐Bin Kuang
Abstract
Abstract Rational design and facile synthesis of efficient environmentally friendly all‐inorganic lead‐free halide perovskite catalysts are of great significance in photocatalytic CO 2 reduction. Aiming at photogenerated charge carrier separation and CO 2 reaction dynamics, in this paper, a CsCuCl 3 /Cu nanocrystals (NCs) heterojunction catalyst is designed and synthesized via a simple acid‐etching solution process by using Cu 2 O as the sacrificed template. Due to the disproportionation reaction of Cu 2 O induced by concentrated hydrochloric acid, Cu NCs can be deposited onto the surface of CsCuCl 3 microcrystals directly and tightly. As revealed by photoelectrochemical analysis, in situ Fourier transform infrared spectra, etc., the Cu NCs contribute a lot to extracting photoelectrons of CsCuCl 3 to improve the charge separation efficiency, regulating the CO 2 adsorption and activation, and also stabilizing the reaction intermediates. Therefore, CsCuCl 3 /Cu heterojunction exhibits a total electron consumption rate of 58.77 µmol g −1 h −1 , which is 2.9‐fold of that of single CsCuCl 3 . Moreover, high CH 4 selectivity of up to 92.7% is achieved, which is much higher than that of CsCuCl 3 (50.4%) and most lead‐free halide perovskite‐based catalysts. This work provides an ingenious but simple strategy to rationally design cocatalysts in situ decorated perovskite catalysts for manipulating both the catalytic activity and the product selectivity.