A novel, highly-efficient, eco-friendly, and relatively stable Cs2AgFeCl6 photocatalyst for degradation of organic dyes

Lead-based halide perovskite is considered to be a potential visible-light-activated photocatalyst owing to its excellent optoelectronic properties. However, the toxicity of lead and the instability of the material restrict its wide application in the field of photocatalysis. A double perovskite structure is thought to be a solution to this problem. The authors prepared a series of samples, including Cs2AgInCl6, Cs2AgIn1_xFexCl6, and Cs2AgFeCl6 through co-precipitation in acidic solutions. The effects of Fe3+ doping on the crystal structure and morphology of Cs2AgInCl6 were characterized by XRD and SEM. Based on density functional theory, VB-XPS and UV-Vis absorption characterizations, the band structure of Cs2AgInCl6 and Cs2AgFeCl6 were determined, showing that the bandgap of Cs2AgIn1_xFexCl6 was reduced linearly by Fe3+ doping. And Sudan Red III can be photocatalytically degraded by all samples under concentrated xenon lamp irradiation of 175 W, with Cs2AgFeCl6 degrading 96% of Sudan Red III in 45 min. In addition, the Cs2AgFeCl6 sample exhibits good cyclic stability and does not demonstrate any significant changes after two months in storage, showing that Cs2AgFeCl6 may serve as an effective and relatively stable Xenon lamp-activated photocatalyst in degradation of organic dyes.