Grinding calcination preparation of WO₃/BiOCl heterostructures with enhanced visible light photocatalytic activity

Abstract

WO3/BiOCl composites with different concentrations of WO3 (1, 2, 4 and 8 wt-%) were synthesised by a grinding calcination method. The as prepared products were characterised by some physicochemical characterisations such as powder X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) emission spectroscopy, and UV-vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity of the prepared samples was evaluated by photocatalytic degradation of acid orange II under visible light irradiation. The effects of the concentration of WO3 and calacination temperature on photocatalytic activity of BiOCl were investigated. The results show that the photocatalytic activity of the prepared heterostructured WO3/BiOCl is superior to pure WO3 and BiOCl. When WO3 and BiOCl powders were grinded together for 30 min and calcined at 200°C for 3 h, the produced WO3/BiOCl composite with 2 wt-%WO3 exhibited 3·6 and 1·2 times increase in photocatalytic activity with respect to BiOCl and WO3 respectively. The presence of WO3/BiOCl heterostructures could effectively enhance the separation efficeince of photo generated electrons and holes, resulting in the high photocatalytic activity.