Z-scheme system of WO3@MoS2/CdS for photocatalytic evolution H2: MoS2 as the charge transfer mode switcher, electron-hole mediator and cocatalyst.

• As a charge transfer mode switcher, MoS 2 can transform the conventional type-II charge transfer mode to Z-scheme. • As electron-hole mediator, MoS 2 can quench the energy of the electrons from WO 3 and the holes from CdS in shorten length. • As a cocatalyst, the CB of MoS 2 can provide active sites for photocatalytic evolution H 2 driven by the electrons from CdS. • WO 3 @MoS 2 /CdS shows improved performance compared with WO 3 /CdS or MoS 2 /CdS owing to the multifunctional roles of MoS 2. A novel ternary Z-scheme system of WO 3 @MoS 2 /CdS is successfully constructed using a three-step wet-chemical route, where MoS 2 locates between the rod-shaped WO 3 and CdS nanoparticles and simultaneously plays multiple roles of the charge transfer mode switcher, electron-hole mediator and cocatalyst. As a charge transfer mode switcher, MoS 2 can transform the conventional type-Ⅱ charge transfer mode to Z-scheme. In such a Z-scheme system, as an electron-hole mediator, MoS 2 is applied to quench the energy of the electrons from WO 3 and the holes from CdS in shorten length, and thus the more left electrons from CdS can transfer to MoS 2 , which can be further applied to photocatalytic evolution H 2 owing to the cocatalyst role of MoS 2. Benefitting from the multifunctional roles of MoS 2 , such a Z-scheme system of WO 3 @MoS 2 /CdS shows an enhanced photocatalytic performance. [ABSTRACT FROM AUTHOR]