Type-II ternary Bi(2)WO(6)/rGO/SnFe(2)O(4) heterojunction nanocomposites and their photocatalytic efficiency towards 4-nitrophenol reduction

In this study, tin ferrite (SnFe(2)O(4)-spinel) and bismuth tungstate (Bi(2)WO(6)) encapsulated on reduced graphene oxide (rGO) were synthesised using the hydrothermal method. This heterostructure nanocomposite was characterised using Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-Vis), powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), FT-Raman Spectroscopy (FT-Raman) and X-ray photoelectron spectroscopy (XPS) methods. The powder XRD results showed an increase in lattice parameters and a decrease in size when SnFe(2)O(4) and Bi(2)WO(6) were encapsulated on rGO. The catalytic activity of the type-II ternary Bi(2)WO(6)/rGO/SnFe(2)O(4) heterojunction nanocomposite was checked using a model reduction reaction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of NaBH(4) as the reducing agent under light exposure. Bi(2)WO(6)/rGO/SnFe(2)O(4) showed better catalytic efficiency than the individual components like SnFe(2)O(4), rGO/SnFe(2)O(4), Bi(2)WO(6), rGO/Bi(2)WO(6) and Bi(2)WO(6)/SnFe(2)O(4) nanocomposites. Thus, the type-II ternary Bi(2)WO(6)/rGO/SnFe(2)O(4) heterojunction nanocatalyst with better surface area and lower surface energy could be considered as a promising UV-light sensitive catalyst for the detoxification of various environmental pollutants and for other environmental remediations.