Fabrication of MoS2/CdIn2S4 Z-scheme heterojunctions with fast interface electronic transfer for highly efficient photocatalytic degradations of multiple organic pollutants

In this work, a novel Z-scheme MoS2/CdIn2S4 (MS-CIS) face-to-face heterostructure with excellent photocatalytic activities for multiple organic pollutant degradation was designed and constructed by a green mild in-situ hydrothermal method, where CdIn2S4 nano-octahedra coated on the surfaces of ultra-thin MoS2 nanosheets to form a face-to-face interface contact. The photocatalytic performance was systematically evaluated by the degradation of Oxytetracycline (OTC) under simulated visible light condition. Compared to MoS2 and CdIn2S4, the as-obtained MS-CIS-3 sample showed significantly improved photocatalytic activities toward OTC degradation, and the rate constant of MS-CIS-3 was 1.29959 h−1, which was 2.31 and 34.16 times those of CdIn2S4 (0.56303 h−1) and MoS2 (0.03804 h−1). The reason for the improvement in photocatalytic performance was that the MS-CIS heterostructure possessed a larger face-to-face contact area which could provide more charge transfer nanochannels, effectively shorten the photogenerated electron transport path and increase the electron-hole separation efficiency. In addition, the possible reaction routes of OTC and the photocatalytic reaction mechanism of MS-CIS sample were also discussed in detail. Furthermore, the MS-CIS-3 heterostructure with excellent photostability and repeatability also possessed outstanding degradation activities for both tetracycline hydrochloride (TCH) and 2-Mercaptobenzothiazole (MBT). This work may provide a promising strategy to synthesize other Z-scheme face-to-face heterostructure photocatalysts with highly efficient photocatalytic activity to solve environmental pollution.