Indium oxysulfide nanosheet photocatalyst for the hexavalent chromium detoxification and hydrogen evolution reaction

Indium oxysulfide nanosheet (In-2(O,S)(3) NS) had been successfully synthesized by a solution-based process at 90 degrees C. To further study some properties of photocatalyst, the 90 degrees C-prepared In-2(O,S)(3) NS was annealed at 350, 400, and 450 degrees C in air for 2 h. It was found that the nanosheet structure at 90 degrees C changed to nanoparticle at higher temperature. All the as-prepared and annealed photocatalysts were carefully characterized and examined toward photocatalytic hexavalent chromium (Cr(VI)) reduction. Among the photocatalysts, 90 degrees Cprepared In-2(O,S)(3) NS exhibited the greatest photocatalytic reduction of Cr(VI) without using any hole scavenger reagent under 150 W visible light illumination. After the Ag deposition on In-2(O,S)(3) NS, the photocatalyst could produce nearly 400 mu mol/g hydrogen gas in ethanol solution under 150 W Xe-lamp irradiation for 5 h. The great performance of 90 degrees C-prepared In-2(O,S)(3) NS was due to the high surface area of nanosheet morphology and the formation of solid solution which significantly increased the visible light absorbance. The photocatalytic activities and their mechanisms of 90 degrees C-prepared In2(O,S)(3) NS were evaluated and elaborated in this work.