Facile in situ solvothermal method to synthesize MWCNT/SnIn4S8 composites with enhanced visible light photocatalytic activity

Superior photocatalytic activity could be achieved by multi-walled carbon nanotube (MWCNT) incorporated in the porous assembly of marigold-like SnIn4S8 heterostructures synthesized by a flexible in-situ solvothermal method. The as-prepared MWCNT/SnIn4S8 composites were well-characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM) and UV-vis diffuse reflectance spectroscopy (DRS). The photocatalytic properties of the as-prepared samples were tested by photo-degradation of aqueous malachite green (MG) under the irradiation of visible light. It was found that the MWCNT/SnIn4S8 composites showed enhanced visible light photocatalytic activity for dye degradation, and an optimum photocatalytic activity was observed over 3.0 wt.% MWCNT incorporated SnIn4S8 composites. The superior photocatalytic activity of MWCNT/SnIn4S8 composites could be ascribed to the existence of MWCNT which could serve as a good electron acceptor, mediator as well as the co-catalyst for dye degradation. The synergistic effect between SnIn4S8 and MWCNT in the composites facilitated the interfacial charge transfer driven by the excitation of SnIn4S8 under visible-light irradiation. Furthermore, a possible mechanism for the photocatalytic degradation of MWCNT/SnIn4S8 composites was also discussed.