Preparation and photocatalytic properties of visible light driven Ag-AgBr-RGO composite

A visible light responsive photocatalyst (Ag-AgBr-RGO) consisting of Ag-AgBr composite dispersed over reduced graphene oxide (RGO) was synthesized via a facile method. The as-prepared samples were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Nitrogen adsorption-desorption measurements, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrum measurements (FTIR), and UV-visible diffused reflectance spectra (UV-vis DRS). The photocatalytic activity of the composite was evaluated by degradation of rhodamine B (RhB) and p-nitrophenol (PNP) under visible light irradiation. The results indicated that the Ag-AgBr-RGO catalyst showed more enhanced photocatalytic activity and stability than the pure Ag-AgBr. The excellent photocatalytic activity of Ag-AgBr-RGO catalyst could be attributed to the heterojunctions among three materials (Ag0, AgBr and RGO). Finally, a possible photo-degradation mechanism was postulated based on the tests of photoactive radicals.