Preparation and characterization of sphere-shaped BiVO4/reduced graphene oxide photocatalyst for an augmented natural sunlight photocatalytic activity

Abstract Sphere-shaped bismuth vanadate (BiVO 4 ) was synthesized by a simple and cost-effective low temperature hydrothermal method. In order to improve the photo-response of the prepared sphere-shaped BiVO 4 in natural sunlight, the as-synthesized BiVO 4 incorporated with graphene oxide (GO) was assembled into sphere-shaped BiVO 4 /reduced graphene oxide (RGO) composites. For studying their morphological, physical, optical, and photo-chemical properties, the obtained composites were well characterized with the aid of various physicochemical techniques, such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflectance, N 2 adsorption/desorption and electrochemical measurements. In addition, the photocatalytic performance of the prepared BiVO 4 and BiVO 4 /RGO composites were evaluated by monitoring the degradation of Rhodamine B (RhB)-contained wastewater under natural sunlight irradiation, where the highest photocatalytic degradation efficiency can be achieved for the BiVO 4 /RGO composites with 3 wt% RGO dosage (approx. 68.85% increase compared with that of pure sphere-shaped BiVO 4 ) The improved photocatalytic activity of BiVO 4 /RGO composite is attributed to the formation of well-defined BiVO 4 -RGO interfaces, which greatly enhances the charge separation efficiency.