Enhanced CO2 photoreduction via tuning halides in perovskites

Development of efficient, selective and low-cost photocatalysts, ideally constructed from Earth-abundant elements, is still a big challenge for CO 2 photoreduction. Herein, adopting mixed halides strategy, the activity of all-inorganic perovskites toward CO 2 reduction is enhanced sharply under simulated sunlight without photosensitizer, meanwhile maintaining high selectivity of CO and CH 4 production. Via regulating ratio of Br and Cl, the yield of CO and CH 4 changes obviously and the optimized catalyst is CsPb(Br 0.5 /Cl 0.5 ) 3 with a total yield of CO and CH 4 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 CsPbBr 3 and CsPbCl 3 under the same condition. The efficient charge separation and moderate stability in mixed-halide perovskites may account for the excellent performance in CO 2 reduction. This study may provide a new strategy in design of high performance and low-cost halide perovskite materials for photocatalysis.