Synthesis, characterization, and visible-light photocatalytic activity of Fe2O3/SnO2 nanocomposites

A novel, visible-light-activated Fe2O3/SnO2 photocatalyst was prepared by the co-precipitation method, and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption–desorption measurement and UV-Vis diffuse reflectance spectroscopy. The phase composition, crystallite size, BET surface area and optical absorption of the sample were found to vary significantly with the calcining temperature. The photocatalytic activities of Fe2O3/SnO2 photocatalysts were evaluated based on the photodegradation of acid blue 62 as a probe reaction. Experimental results indicated that the Fe2O3/SnO2 photocatalyst calcined at 400 °C for 3 h (the molar ratio of Fe to Sn is 2:1) exhibited maximum photocatalytic activity due to the sample with a smaller particle size of 15 nm and a higher surface area of 28.8 m2źg–1. Under visible light (.lambda > 400 nm) irradiation, the degradation rate of acid blue 62 reached 98.0% in 60 min, which is about 3.6 times higher than that of the standard P25 photocatalyst. Additionally, the efficient electron–hole separation at the Fe2O3/SnO2 photocatalyst interface may play another important role in photodegradation.