Insights into the photocatalytic performance of BiOCO/BiVO heterostructures prepared by one-step hydrothermal method.

This paper describes the synthesis of BiOCO/BiVO heterostructures through a one-step method based on the difference in solubility between two semiconductors that possess a metal in common. The as-synthesized BiOCO/BiVO heterostructures were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Raman spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N physisorption, X-ray photoelectron spectroscopy (XPS) and time resolved photoluminescence spectroscopy (TRPL). The role of the heterojunction formed was evaluated by methylene blue (MB) dye and amiloride photodegradation. The formation of the heterostructure was observed indirectly by the great increase in the thermal stability of the BiOCO phase when compared to its pure phase. The amount of heterojunctions formed between the BiOCO and BiVO was tuned by vanadium precursor concentration. The proposed strategy was efficient for obtaining BiOCO/BiVO heterostructures with enhanced photocatalytic performance when compared to their isolated phases, MB and amiloride photodegradation occurred mainly by the action of ˙OH radicals, by an indirect mechanism. Based on TRPL spectroscopy and VB-XPS results, an enhancement of photoactivity related to an increase in the spatial separation of photo-generated electron/hole pairs was observed due to the formation of a type-II heterostructure.