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

Abstract

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 BiVO 4 /BiOI composite integrating both the core/shell heterostructure and semiconductor p–n junction at room temperature. In the BiVO 4 /BiOI core/shell heterostructure, the BiOI nanosheets are evenly assembled on the surface of the BiVO 4 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 BiVO 4 /BiOI core/shell photocatalyst shows drastically enhanced photocatalysis properties compared to the pristine BiVO 4 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 BiVO 4 . 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 (•O 2 – ) quantification results. Moreover, the core/shell BiVO 4 /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.