Controllable synthesis of plasmonic Ag/AgBr photocatalysts by a facile one-pot solvothermal route

摘要

Plasmonic photocatalysts Ag/AgBr composites were synthesized by a facile one-step solvothermal route. Unlike the traditional photoreduction method, metallic Ag in the present work was in situ anchored on the surface of AgBr by reducing radicals created through the thermal process. The structures (e.g., particle size, composition, and dispersion) of metallic Ag nanoparticles could be well controlled by simply changing the reaction temperature and solvent. The as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectra (DRS). The as-prepared Ag/AgBr composites exhibited excellent photocatalytic efficiency for the degradation of azo dye methyl orange (MO), phenol, and 2-chlorophenol under visible light irradiation. It was found that the activity was highly dependent on the particle size, composition and the dispersing extent of Ag nanoparticles. The photocatalytic mechanism was studied by radical-trapping experiments and the photoluminescence (PL) technique with terephthalic acid, and the results indicated that ·O_2~- and h~+ played great roles in the rapid degradation of organic pollutants under visible light irradiation.