Enhanced Photocatalytic Activity for 4-Nitrophenol Degradation Using Visible-Light-driven In2S3/α-Fe2O3 Composite

In2S3/α-Fe2O3 composites were synthesized using the methods of hydrothermal treatment and reflux. Characterization such as X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and Photoluminescence (PL) was used to characterize the crystallinity and morphology of the composites, which proved the successful synthesis of the In2S3/α-Fe2O3 heterostructures. The 4-nitrophenol (PNP) degradation experiments by visible light were studied to evaluate the photocatalytic activity of the In2S3/α-Fe2O3 composites. The composites showed much higher photocatalytic degradation activities and TOC removal rate than both pure In2S3 and α-Fe2O3. The PNP degradation rate of composites was about 4.7 and 11.9 times that of pure In2S3 and α-Fe2O3, respectively. The degradation process was detected by high performance liquid chromatography and mass spectrometry, and the degradation pathway was explained. Based on the trapping experiments, e− and •OH were the main active species and a Z-scheme photocatalytic mechanism of In2S3/α-Fe2O3 was proposed, which showed the double advantage of high redox ability and efficient electron-hole pairs separation.