Fabrication of In2O3-SnS2 Core–Shell Heterojunction for Efficient Photocatalytic Removal of Hexavalent Chromium

Abstract

The development of heterojunction composites with core–shell structure could effectively facilitate the separation of carriers. In this work, a novel In2O3-SnS2 (IOS) core–shell heterojunction photocatalyst was successfully synthesized for the efficient photocatalytic reduction of hexavalent chromium (Cr(VI)), namely, the In2O3 nanorods were obtained through successive hydrothermal and carbonization process using urea and glucose as template. Then, SnS2 nanosheets were successfully in situ coated onto In2O3 nanorods. The spectroscopic characterization and photo-electrochemistry test indicated that the IOS core–shell heterojunction could effectively accelerate the separation and transport of carriers and suppress the recombination of carriers. The photocatalytic performance of IOS was evaluated by photocatalytic reduction Cr(VI). The results showed that IOS-4 samples almost completely removed Cr(VI) (20 mg/L), within 90 min under visible light, which was superior to pure In2O3 and SnS2. Furthermore, IOS samples also possess excellent stability, the removal efficiency was still maintained at 90% after five cycles. This work provided a reliable method for designing core–shell heterojunctions for the photocatalytic removal of Cr(VI) under visible light.