Highly stable lead-free Cs2AgBiI6-GO composite photocatalysts for efficient organic pollutant degradation

Abstract

The use of halide perovskites as photocatalysts has attracted more and more attention. However, the instability and toxicity of the lead halide perovskites have hindered their practical large-scale application. Herein, lead-free Cs2AgBiI6 double perovskite was synthesized by a simple antisolvent recrystallization approach for photocatalysis. Meanwhile, in order to solve the limited photocatalytic performance problem of the pure metal halide perovskites, for the first time, we designed and prepared highly stable Cs2AgBiI6-Graphene oxide (GO) composite photocatalyst. The photodegradation rate of Sudan Red III by Cs2AgBiI6-GO was found to be as high as 85% after 100 min of light irradiation, which was twice that of the pure Cs2AgBiI6 and also more efficient than recently reported photocatalysts under comparable conditions. This work demonstrated that the GO with unique physicochemical properties could prevent the photocatalyst agglomeration and provide charge carrier transport channel to inhibit electron-hole recombination to improve the overall photocatalytic performance.