Fabrication of Hierarchically Porous Reduced Graphene Oxide/SnIn4S8 Composites by a Low-Temperature Co-Precipitation Strategy and Their Excellent Visible-Light Photocatalytic Mineralization Performance

Hierarchically porous reduced graphene oxide/SnIn4S8 (RGO/SnIn4S8) composites with visible-light response and strong mineralization ability were first successfully prepared by a facile low-temperature co-precipitation method, and were characterized by X ray diffraction (XRD), scanning electron microscope (SEM), Brunauer-Emmet-Teller (BET), UV-Visible spectrophotometer (UV-Vis), Raman spectra and Photoluminescence (PL) techniques. RGO/SnIn4S8 composite exhibits strong absorption in UV and visible-light range. The optimized 5% RGO/SnIn4S8 possesses the optimal photocatalytic degradation efficiency and the best mineralization performance with complete degradation of Rhodamine B (RhB) within 70 min and 73.17% mineralization yield within 160 min under visible-light irradiation, which is much higher than that of pure SnIn4S8. The main reactive species, which play crucial roles in the degradation and mineralization of RhB, follow the order of h+ > ̈O2 ́ > ̈OH. The intermediate products of RhB degradation were analyzed by using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS), and the possible degradation pathways and mechanism were proposed. Moreover, 5% RGO/SnIn4S8 exhibits excellent reusability and stability without an obvious decrease in photocatalytic activity after four consecutive photocatalytic degradation-regeneration experiments.