Preparation of BiVO4/bentonite catalysts and their photocatalytic properties under simulated solar irradiation

A series of BiVO4/bentonite catalysts calcined at different temperatures were prepared by the solution combustion method and characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), Brunauer–Emmett–Teller (BET) specific surface area and ultraviolet–visible diffuse reflectance (UV–vis DRS) spectra. The results of BET analysis showed that BET specific surface area of BiVO4/bentonite crystallite decreased with increasing calcination temperature. The results of XRD, FE-SEM and UV–vis DRS analysis indicated that BiVO4 on bentonite calcined at 300 °C was in a monoclinic structure with a diameter of around 30 nm, as well as strong absorbance in a region of 350–500 nm. The photocatalytic activities of as-prepared catalysts were discussed by the degradation of C.I. Reactive Blue 19 (RB19) under simulated solar irradiation. It was found that the catalyst could be separated from aqueous suspensions by sedimentation after reaction, and maintained almost the same activity after being used five times.