Deposition of Ag@AgCl onto Flower-Like BiOCl for Promoting the Degradation of Methyl Orange: The Narrow Bandgap and Surface Plasmon Resonance Effect

Photocatalysis technology is considered as a most promising method to decompose organic pollutant since the inexhaustible solar energy and facile reaction condition. Herein, a series of flower-like Ag/AgCl/BiOCl photocatalysts are successfully synthesized via hydrothermal and photochemical deposition method. All the samples are investigated and characterized by X-Ray diffraction, Scanning electron microscopy, transmission electron microscope, ultraviolet–visible spectroscopy and Photoluminescence to insight into the microstructures and optical properties. During the photocatalytic degradation of Methyl orange experiments, the optimized Ag/AgCl/BiOCl sample prepared by photoreduction with 40 min exhibits the excellent photocatalytic performance. Under visible-light irradiation for 60 min, degradation rate of Methyl orange reaches 97%, which is 9.7, 6.1 and 4.6 times higher than that of AgCl, Ag/BiOCl and BiOCl, respectively. The UV–vis diffuse reflectance and Photoluminescence spectra of the Ag/AgCl/BiOCl photocatalyst verify that the enhanced photocatalytic activity is ascribed to its extended absorption range to visible-light region and the efficient separation efficiency of photogenerated carriers. In addition, the radical trapping experiment demonstrates that photogenerated hole and superoxide radicals play critical roles in the methyl orange degradation. The corresponding photocatalytic degradation mechanism is proposed that the excellent photocatalytic activity is attributed to the surface plasmon resonance effect of metallic Ag and heterojunction structure of Ag/AgCl/BiOCl photocatalysts.