Facile fabrication of a novel spindlelike MoS2/BiVO4 Z-scheme heterostructure with superior visible-light-driven photocatalytic disinfection performance

Abstract

Novel MoS2/BiVO4 porous spindlelike heterostructures (MBV SHs) were successfully constructed via a facile in-situ hydrothermal approach, which were consisted of spindles with hierarchical squamous nanosheets (NSs) covering throughout the surface. A possible formation mechanism of MBV SHs was studied and proposed, illustrating an in-situ growth of BiVO4 crystals on MoS2 NSs followed by a self-assembly process through Ostwald ripening and anisotropic growth with the assistance of polyvinylpyrrolidone (PVP). The photocatalytic activities of the obtained samples were systematically studied by the inactivation of Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) under visible light irradiation. Results indicated that MBV SHs displayed a greatly improved photocatalytic antibacterial performance compared with pure BiVO4 and MoS2, among which MBV-4 can kill almost all bacteria within 90 min. The enhanced photocatalytic property can be ascribed to the formation of Z-scheme heterojunction and rich oxygen vacancies (OVs) in MBV SHs, leading to the stronger photoabsorption ability, faster separation of photoinduced charge carriers, and more robust redox capacity. Moreover, the photocatalytic mechanism of Z-scheme heterojunction was investigated in detail according to the radicals capture and electron spin resonance (ESR) tests combined with the first-principle theoretical calculation, verifying that ∙O2– and h+ played significant roles in the photocatalytic process. This study provides a novel Z-scheme heterojunction with prospective application possibility in environmental purification.