Ion-exchange preparation for visible-light-driven photocatalyst AgBr/Ag2CO3 and its photocatalytic activity

The AgBr/Ag2CO3 composite was synthesized by an ion-exchange reaction. The physical and chemical properties of the catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), transmission electron microscopy (TEM), diffuse-reflection spectra (DRS) and photocurrent techniques. The photocatalytic performance of the samples was evaluated by photocatalytic oxidation of methylene blue (MB) dye under visible-light irradiation. The XRD, SEM-EDS, TEM, and XPS analyses indicated that the heterojunction structure had been obtained. The results indicated that the AgBr/Ag2CO3 heterojunction had exhibited a much higher photocatalytic activity than the pure Ag2CO3. The enhancement of photocatalytic activity was related to the efficient separation of electron-hole pairs because of the stagger band potentials between AgBr and Ag2CO3.