Construction of In2S3/UiO-67 heterojunction for photocatalytic removal of Cr(Ⅵ) and RhB

Abstract

Regarding the poor visible light response and the difficulty in synchronously driving photocatalytic reduction and oxidation reactions of MOFs, In2S3/UiO-67 composites (IM-1, IM-3, and IM-5) were prepared by deposition of in situ generated In2S3 species on the surface of UiO-67(Zr-MOF), and the formation of heterostructure was confirmed by PXRD, FT-IR and XPS characterization. Under the irradiation of 500 W xenon lamp, the reduction efficiency of IM-3 for Cr(Ⅵ) reached 92.4% within 60 min, providing the reduction rate of 2.3 and 20 times that of pure In2S3 and Zr-MOF, respectively. The degradation efficiency for RhB was 78% within 180 min, with the degradation rate of 1.75 and 2.3 times of that of pure In2S3 and Zr-MOF. Moreover, the migration direction of photogenerated carriers were elucidated by XPS, and the photocatalytic reaction mechanism was further revealed in combination with free radical trapping experiments.

Keywords

• heterojunction
• reactive dyes
• cr(ⅵ)
• photocatalytic reduction and degradation