Hydrothermal synthesis of visible light active zinc-doped tin disulfide photocatalyst for the reduction of aqueous Cr(VI)

A facile one-step hydrothermal route, which was based on the reactions of SnCl4·5H2O, Zn(NO3)2·6H2O and thioacetamide in 10 vol.% acetic acid aqueous solution in an autoclave at 120 °C for 24 h, was proposed for the synthesis of Zn2 +-doped SnS2 (which was hereinafter called “Zn-SnS2” for the convenience of description) nanoparticles. The composition, structure, BET specific surface area and optical property of the as-synthesized Zn-SnS2 nanoparticles were characterized by energy dispersive X-ray fluorescence spectrometer, X-ray photoelectron spectroscopy, X-ray diffraction, Raman, transmission electron microscopy, N2 adsorption–desorption isotherms and UV–Vis diffuse reflectance spectrum, and their photocatalytic property was tested for the first time by the reduction of aqueous Cr(VI) under visible light (λ > 420 nm) irradiation. Results demonstrated that Zn-SnS2 nanoparticles possessed higher visible light-driven photocatalytic activity than SnS2 nanoparticles (which were hydrothermally synthesized under the same conditions, except for the absence of Zn(NO3)2·6H2O). Moreover, Cr(VI) was reduced to Cr(III) after the Zn-SnS2-mediated photocatalytic reactions.