Lead-free perovskite Cs2XCl6 (X = Hf, Zr, Te) microcrystals for photocatalytic CO2 reduction

The lead halide perovskites have broad application prospects in the fields of optoelectronics and photocatalysis. However, their toxicity and limited stability are the main obstacles restricting their large-scale photocatalytic applications. In order to solve these problems, a set of lead-free stable Cs2XCl6 (X = Hf, Zr, Te) perovskite microcrystals were synthesized via a solvothermal solution. For the first time, the Cs2XCl6 (X = Hf, Zr, Te) perovskite microcrystals were employed as efficient photocatalysts for the conversion of CO2 into CO and CH4. Among them, the Cs2TeCl6 microcrystals showed the best photocatalytic performance under light irradiation for 3 h, while the yields of CO and CH4 were 284.4 μmol/g and 48.96 μmol/g respectively. Our strategy may provide a new idea for the CO2 photoreduction based on lead-free halide perovskites.