Enhanced visible light photocatalysis and mechanism insight for novel Z-Scheme MoS₂/Ag₂S/AgVOₓ ternary heterostructure with fast interfacial charges transfer

A Z-scheme MoS₂/Ag₂S/AgVOₓ ternary heterostructure was successfully synthesized by a facile hydrothermal method. The as-prepared MoS₂/Ag₂S/AgVOₓ ternary composite has been characterized by electron microscopy, XRD, XPS, UV-Vis DRS, PL, electrochemistry and ESR. TEM characterization revealed that Ag₂S, Ag nanoparticles and AgVOx nanorods were dispersed homogeneously over the surface of MoS₂ nanosheets The prepared heterojunction showed enhanced photocatalytic performance compared with single MoS₂ and AgVOₓ And 6%-MoS₂/Ag₂S/AgVOₓ heterojunction exhibits highest photocatalytic degradation efficiency, which can degrade fuchsine around 75% under visible light within 180 min. The enhanced photocatalytic activity can be attributed to the efficient separation of photogenerated charge carriers, the strong redox ability and enhancement of visible-light absorption derived from the construction of Z-scheme heterostructure. In-situ formed metallic Ag₂S act as the electron mediator and Ag nanoparticles possess the surface plasmon resonance (SPR) effect. The prepared heterojunction showed decreased photoluminescence and increased photoelectrochemical performance, indicating high separation rate of photoinduced charge carriers. Furthermore, a possible degradation mechanism of fuchsine solution was proposed. And the results of radical trapping experiments indicated that superoxide radicals (∙O₂⁻) and holes (h⁺) play major role during the photocatalytic degradation process. This work demonstrates an interesting Z-scheme photocatalytic system for photocatalysis applications. Copyright © 2022 Elsevier B.V.