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).