Z-scheme CdIn2S4/BiOCl nanosheet face-to-face heterostructure: in-situ synthesis and enhanced interfacial charge transfer for high-efficient photocatalytic performance

In this work, a novel Z-scheme CdIn2S4 nano-octahedron/BiOCl nanosheet (CIS/BOC) heterostructure was successfully designed and synthesized via a facile in-situ hydrothermal process, where the CdIn2S4 nano-octahedra grew on the surfaces of tiny BiOCl nanosheets in a face-to-face way. The structure, morphology and optical properties of as-prepared samples were characterized through various technologies. The photocatalytic activities were systematically evaluated by the degradation of methyl orange (MO), tetracycline hydrochloride (TCH) and rhodamine B (RhB) under simulated solar light irradiation. The degradation results displayed that all CIS/BOC composites exhibited significantly enhanced photocatalytic activities toward MO degradation in comparison with the bare CdIn2S4 and BiOCl. Simultaneously, the obtained CIS/BOC-2 with 6 wt.% BiOCl nanosheets loaded possessed the optimal photocatalytic performance, and its rate constant was about 3.6 and 2.59 times as high as those of bare CdIn2S4 and BiOCl. Furthermore, the CIS/BOC-2 nanocomposite with superior photostability and repeatability also presented high photocatalytic activities for the removal of both antibiotics (TCH) and dyestuff (RhB). The unique Z-scheme face-to-face heterostructure with intimate contacted interface in CIS/BOC-x nanocomposites provided more charge transfer nanochannels, shortened the migration distance and boosted the separation of photoinduced charge carriers, resulting in the excellent photocatalytic activities. Our study may provide a promising strategy to develop and synthesize other Z-scheme face-to-face composite photocatalysts with good photocatalytic performance.