A General and Facile Approach to Heterostructured Core/Shell BiVO4/BiOI p-n Junction: Room-Temperature in Situ Assembly and Highly Boosted Visible-Light Photocatalysis

摘要

Development of core/shell heterostructures and semiconductor p-n junctions is of great concern for environmental and energy applications. Herein, we develop a facile in situ deposition route for fabrication of a BiVO4/BiOI composite integrating both the core/shell heterostructure and semiconductor p-n junction at room temperature. In the BiVO4/BiOI core/shell heterostructure, the BiOI nanosheets are evenly assembled on the surface of the BiVO4 cores. The photocatalytic performance is evaluated by monitoring the degradation of the dye model Rhodamine B (RhB), colorless contaminant phenol, and photocurrent generation under visible-light irradiation. The heterostructured BiVO4/BiOI core/shell photocatalyst shows drastically enhanced photo-catalysis properties compared to the pristine BiVO4 and BiOI. This remarkable enhancement is attributed to the intimate interfacial interactions derived from the core/shell heterostructure and formation of the p-n junction between the p-type BiOI and n-type BiVO4. Separation and transfer of photogenerated electron-hole pairs are hence greatly facilitated, thereby resulting in the improved photocatalytic performance as confirmed by electrochemical, photoelectrochemical, radicals trapping, and superoxide radical (·O2~-) quantification results. Moreover, the core/shell BiVO4/BiOI also displays high photochemical stability. This work sheds new light on the construction of high-performance photocatalysts with core/shell heterostructures and matchable band structures in a simple and efficient way.