Efficient Degradation of Azo Dyes over Sb 2 S 3 /TiO 2 Heterojunction under Visible Light Irradiation

A cost- and time-saving coupling method was developed to prepare a novel Sb 2 S 3 /TiO 2 heterostructure photocatalyst. The obtained sample was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV–vis diffuse reflectance spectroscopy (DRS). UV–vis diffuse reflectance spectra showed a great shift to longer wavelengths and an extension of the absorption in the visible region for all of the samples compared to pure TiO 2 . The photocatalytic activity of the sample was investigated for the liquid-phase photocatalytic degradation of azo dyes under visible light irradiation. The influences of different mass ratios of Sb 2 S 3 and sintered temperatures on the photocatalytic activity have also been investigated, and the highest efficiency is observed when calcined at 673 K with 60 wt % Sb 2 S 3 content. Moreover, •OH has also been detected in the suspension of Sb 2 S 3 /TiO 2 heterojunction under visible light irradiation, which leads to the decomposition of azo dyes.