Enhanced CO2 photoreduction via tuning halides in perovskites

Abstract

Development of efficient, selective and low-cost photocatalysts, ideally constructed from Earth-abundant elements, is still a big challenge for CO2 photoreduction. Herein, adopting mixed halides strategy, the activity of all-inorganic perovskites toward CO2 reduction is enhanced sharply under simulated sunlight without photosensitizer, meanwhile maintaining high selectivity of CO and CH4 production. Via regulating ratio of Br and Cl, the yield of CO and CH4 changes obviously and the optimized catalyst is CsPb(Br0.5/Cl0.5)3 with a total yield of CO and CH4 up to 875 μmol/g (selectivity of 99%) which outperforms any other reported halide perovskites and is 4.5 and 9.1 folds higher than that of CsPbBr3 and CsPbCl3 under the same condition. The efficient charge separation and moderate stability in mixed-halide perovskites may account for the excellent performance in CO2 reduction. This study may provide a new strategy in design of high performance and low-cost halide perovskite materials for photocatalysis.