Facile preparation of visible-light-responsive kaolin-supported Ag@AgBr composites and their enhanced photocatalytic properties

A novel visible light responsive Ag@AgBr/kaolin photocatalyst was synthesized via in-situ deposition-precipitation method. The X-ray diffraction (XRD) and high-resolution transmission electron spectroscopy (HRTEM) analysis proved the formation of Ag@AgBr nanoparticles in the surface of kaolin clay. The phases, chemical compositions and optical properties of the as-prepared Ag@AgBr/kaolin composite were well characterized by X-ray photoelectron spectroscopy (XPS) and UV-visible diffused reflectance spectra. The photocatalytic activity of the Ag@AgBr/kaolin composite was investigated by the degradation of methyl orange (MO) and rhodamine B (RhB) solution under visible light irradiation.The Ag@AgBr/kaolin composite could be effectively applied over a wide range of pH 2.54-10.95 in the degradation of typical dyes and also showed higher stability and reusability capacity even after four cycles. Active radical trapping experiments suggested that the boosting photocatalytic activities was enhanced due to the moreactive sites, large surface area, and surface plasmonic resonance of metallic Ag nanoparticles on the surface of AgBr. This study might provide a newinsight into the design of high-efficiency clay-supported photocatalyst for organic pollutants degradation and environmental remediation.