No abstract

In view of the toxicity of the Pb element, exploring eco-friendly Pb-free halide perovskites with excellent photoelectric properties is of great research and practical application significance. Herein, copper-based halide perovskite CsCuCl3 and the corresponding Br–-substituted sample (CsCuCl2Br) are designed and explored as the catalysts for photocatalytic CO2 reduction for the first time. A facile antisolvent recrystallization process with pre-prepared single crystals as the precursor is employed to controllably synthesize CsCuCl3 and CsCuCl2Br microcrystals (MCs). The electronic structure and charge transfer property analysis by theoretical and experimental investigation reveal that CsCuCl3 possesses a satisfying bandgap (1.92 eV) and conduction band minimum (CBM) to harvest the sunlight and drive the conversion of CO2 to CH4 and CO. The Br– substitution can not only narrow the bandgap but also facilitate the transportation of charge carriers. Thus, a total electron consumption rate of 44.71 μmol g–1 h–1 is achieved for CsCuCl2Br MCs, which is much better than that of same-sized CsPbBr3 microcrystals or even better than many perovskite nanocrystal photocatalysts. This study suggests that Cu-based perovskites can serve as promising candidates for artificial photosynthesis or other photocatalytic applications, which may propose a new thought to construct lead-free, low-cost photocatalysts.

The severe photogenerated charge carrier recombination and the poor CO2 adsorption capacity are regarded as the two main factors impeding the photocatalytic CO2 reduction performances of metal halide perovskite (PVK)...

Rational design and facile synthesis of efficient environmentally friendly all‐inorganic lead‐free halide perovskite catalysts are of great significance in photocatalytic CO2 reduction. Aiming at photogenerated charge carrier separation and CO2 reaction dynamics, in this paper, a CsCuCl3/Cu nanocrystals (NCs) heterojunction catalyst is designed and synthesized via a simple acid‐etching solution process by using Cu2O as the sacrificed template. Due to the disproportionation reaction of Cu2O induced by concentrated hydrochloric acid, Cu NCs can be deposited onto the surface of CsCuCl3 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 CsCuCl3 to improve the charge separation efficiency, regulating the CO2 adsorption and activation, and also stabilizing the reaction intermediates. Therefore, CsCuCl3/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 CsCuCl3. Moreover, high CH4 selectivity of up to 92.7% is achieved, which is much higher than that of CsCuCl3 (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.