One-step hydrothermal fabrication of SrMoO4/MoS2 composites with strong interfacial contacts for efficient photoreduction removal of Cr(vi)
Abstract
Aimed at alleviating severe recombination of photogenerated electron/hole pairs in MoS2 photocatalysts, one-pot hydrothermal preparation of SrMoO4/MoS2 composites was successfully achieved in this study. It was found that numerous MoS2 nanosheets were in situ grown on the surface of bulk SrMoO4; meanwhile, XPS and Raman analyses indicated that a strong interfacial effect was generated between bulk SrMoO4 and MoS2 nanosheets in 8%-SrMoO4/MoS2 composites. Moreover, the intense heterojunction interface of 8%-SrMoO4/MoS2 composites greatly promotes the separation of photoinduced electron–hole pairs and speeds up the transfer of photoinduced charge carriers. Compared with pure MoS2 and bulk SrMoO4 photocatalysts, the series of x-SrMoO4/MoS2 composites possess enhanced photoreduction activities, especially the 8%-SrMoO4/MoS2 photocatalyst displays optimal removal efficiency of Cr(VI) (91.2%) and excellent photostability under visible light irradiation. As a matter of fact, an in situ hybrid process occurs during the preparation of 8%-SrMoO4/MoS2 composites, resulting in intense interfacial contacts, which mainly endow them with superior photocatalytic performance. Finally, the photocatalytic mechanism is studied to illustrate the efficient transfer of photoinduced electron/hole pairs and the removal process of Cr(VI).