Enhanced interfacial electronic transfer of BiVO4 coupled with 2D g-C3N4 for visible-light photocatalytic performance

A BiVO4/2D g-C3N4 direct dual semiconductor photocatalytic system has been fabricated via electrostatic self-assembly method of BiVO4 microparticle and g-C3N4 nanosheet. According to experimental measurements and first-principle calculations, the formation of built-in electric field and the opposite band bending around the interface region in BiVO4/2D g-C3N4 as well as the intimate contact between BiVO4 and 2D g-C3N4 will lead to high separation efficiency of charge carriers. More importantly, the intensity of bulid-in electric field is greatly enhanced due to the ultrathin nanosheet structure of 2D g-C3N4. As a result, BiVO4/2D g-C3N4 exhibits excellent photocatalytic performance with the 93.0% Rhodamine B (RhB) removal after 40 min visible light irradiation, and the photocatalytic reaction rate is about 22.7 and 10.3 times as high as that of BiVO4 and 2D g-C3N4, respectively. In addition, BiVO4/2D g-C3N4 also displays enhanced photocatalytic performance in the degradation of tetracycline (TC). It is expected that this work may provide insights into the understanding the significant role of built-in electric field in heterostructure and fabricating highly efficient direct dual semiconductor systems.