Efficient photocatalytic reduction of aqueous Cr(VI) over flower-like SnIn4S8 microspheres under visible light illumination

Photocatalytic reduction of aqueous Cr(VI) was successfully achieved on nanostructured SnIn4S8. The SnIn4S8 particles with flower-like nanostructure were synthesized via a facile solvothermal method. UV-vis diffuse reflectance spectra (DRS) indicated that the SnIn4S8 particles had strong absorption in visible region and the band gap was estimated to be from 2.27 to 2.35 eV. The photocatalytic reduction of aqueous Cr(VI) by flower-like SnIn4S8 was evaluated under visible light (lambda > 400 nm) irradiation. The polyvinyl pyrrolidone (PVP) assisted SnIn4S8 sample exhibits excellent removal efficiency of Cr(VI) (similar to 97%) and good photocatalytic stability. The predominant photocatalytic activity is due to its large surface area, strong absorption in visible-light region and excellent charge separation characteristics. (c) 2012 Elsevier B.V. All rights reserved.