Synthesis of MoS2/SnWO4 nanocomposite heterostructures: photocatalytic degradation of tetracycline upon visible-light irradiation

Abstract

In this study, MoS₂ and SnWO₄ nanocompounds were synthesized by a simple hydrothermal method. Further, three different MoS₂/SnWO₄ nanocomposites, MSSW-5, MSSW-10, and MSSW-15 were synthesized using MoS₂ with various amounts of SnWO₄ by a solvothermal method. The crystal phases of the synthesized nanostructures were confirmed by X-ray diffraction (XRD) analysis. Scanning electron microscopy and transmission electron microscopy results demonstrated that the SnWO₄ nanoplates were deposited on the MoS₂ nanosheets, forming the MoS₂/SnWO₄ heterostructure. A sufficient band alignment was achieved for the MoS₂/SnWO₄ nanocomposites owing to the formation of strong interfaces at the heterostructure. The prepared samples were investigated for the degradation of tetracycline (TC) under visible light. MSSW-10 demonstrated the best photocatalytic activity (96.47%) for the degradation of TC under visible light within 80 min. The rate constant of the MSSW-10 nanocomposite is approximately 6.89 and 9.07 times higher than that of pristine MoS₂ and SnWO₄, respectively. Moreover, the prepared photocatalyst exhibited good reusable properties and high stability. Thus, the MoS₂/SnWO₄ nanocomposites with a suitable bandgap promoted the efficient electron-hole pair carrier transfer, contributing to the efficient photocatalytic activity.