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 Cs ₂AgInCl ₆, Cs ₂AgIn _1−xFe _xCl ₆, and Cs ₂AgFeCl ₆ through co-precipitation in acidic solutions. The effects of Fe ³⁺ doping on the crystal structure and morphology of Cs ₂AgInCl ₆ were characterized by XRD and SEM. Based on density functional theory, VB-XPS and UV-Vis absorption characterizations, the band structure of Cs ₂AgInCl ₆ and Cs ₂AgFeCl ₆ were determined, showing that the bandgap of Cs ₂AgIn _1−xFe _xCl ₆ was reduced linearly by Fe ³⁺ doping. And Sudan Red III can be photocatalytically degraded by all samples under concentrated xenon lamp irradiation of 175 W, with Cs ₂AgFeCl ₆ degrading 96% of Sudan Red III in 45 min. In addition, the Cs ₂AgFeCl ₆ sample exhibits good cyclic stability and does not demonstrate any significant changes after two months in storage, showing that Cs ₂AgFeCl ₆ may serve as an effective and relatively stable Xenon lamp-activated photocatalyst in degradation of organic dyes.