3D hierarchical structure collaborating with 2D/2D interface interaction in BiVO4/ZnCr-LDH heterojunction with superior visible-light photocatalytic removal efficiency for tetracycline hydrochloride

Abstract

Fabrication of heterojunction with specialized geometry shape could improve the photodegradation efficiency of catalysts more efficiently based on the synergistic effect of components. Herein, the BiVO4/ZnCr-LDH type-II heterojunction was successfully synthesized by the growth of two-dimensional (2D) ZnCr-LDH on 2D BiVO4, forming a unique three-dimensional (3D) hierarchical structure. The 3D hierarchical BiVO4/ZnCr-LDH type-II heterojunction with intimate 2D/2D heterointerfaces enlarges the interfacial contact areas and shortens the transfer distance of carriers simultaneously, which could promote the separation and transfer of photoinduced carriers and prolong the lifetime of carriers. Additionally, the 3D structure could enhance the photon utilization efficiency caused by the multiple reflections of incident light, and provide more active sites to promote the adsorption of pollutants. Therefore, the visible light catalytic performance of the optimal heterostructure for the removal of tetracycline hydrochloride is 3.47 times and 22.43 times higher than that of BiVO4 and ZnCr-LDH, respectively. Superoxide radical (·O2−) is confirmed as the primary active species, whereas hole (h+) is the secondary active species in the photodegradation process. This work provides a facile strategy to enhance the visible light catalytic behavior of BiVO4 through the fabrication of 3D hierarchical architecture heterojunction for the removal of organic pollutant.

Keywords

• BiVO4
• ZnCr-LDH
• Hierarchical structure
• Type II heterojunction
• Photocatalysis