Hydrothermal synthesis of W-doped BiOCl nanoplates for photocatalytic degradation of rhodamine B under visible light

Doping bismuth oxychloride (BiOCl) with other elements can help improve its photocatalytic performance. The present study used a simple one-step hydrothermal method to synthesize tungsten-doped BiOCl nanosheets. The results showed the negligible effects of W-doping on the crystal structure, morphology and specific surface area of BiOCl. Diffuse reflectance spectroscopy (DRS), however, showed increases in light absorption and a shift in the absorption edge towards higher wavelengths in the presence of W. Measuring the photocatalytic performance of the samples in decomposing an aqueous solution of rhodamine B (RhB) under light irradiation showed that doping BiOCl with W preserves photocatalytic performance under both UV irradiation and visible-light irradiation, whereas pure BiOCl showed negligible photocatalytic activities under visible-light irradiation. The high photocatalytic activity of BiOCl doped with W compared to that of pure BiOCl is explained by the reduction in band gap and increase in light absorption due to the formation of W energy bands in the forbidden energy gap of BiOCl. A plausible mechanism was proposed for the photocatalytic activity of W-doped BiOCl in decomposing RhB under visible light.