Photocatalytic reduction of Cr(VI) and degradation of RhB by assembled novel In2S3/Zr-biquinoline framework heterojunction photocatalyst via xenon lamp

Abstract

Dichromates and dyes have been widely used in industrial and agricultural production, but they are also responsible for the deterioration of water environments. Photochemical purification of them based on MOFs based photocatalysts has been proven to be feasible. And construction of MOFs based heterojunctions to polish the band states is an effective method for enhancing the separation of photogenerated electron-hole separation and carriers migration under low energy light. Herein, a Zr(IV)-biquinoline framework with bcu topology was synthesized to act as a matrix for depositing the in-situ generated In2S3 species, providing a novel In2S3/Zr-MOF heterojunction. Indeed, owing to the highly matched band structure of the two components, the new heterojunction exhibits optimized visible light utility, photogenerated electron-hole recombination inhibition ability and carriers migration kinetics. Ingeniously, the 10%-Zr-MOF exhibited excellent photocatalytic REDOX abilities against Cr(VI) ions and dye RhB, with the photocatalytic deoxidation efficiency towards Cr(VI) ions (96.7 %) has been confirmed to be 3.14 and 1.42 times that of pristine Zr-MOF (30.8 %) and sole In2S3 (68.2 %), respectively. Moreover, it also displayed a photocatalytic reduction kinetic rate of 0.031 min−1, which is 11.3 times and 2.69 times higher than that of fresh Zr-MOF (0.00274 min−1) and pure In2S3 (0.0115 min−1). And the photocatalytic reduction and degradation mechanisms of In2S3/Zr-MOF also have been deliberately proposed, according to the detailed experimental and instrumental characterization results. This contribution presents a feasible post-modification reinforcement strategy to assemble novel Zr-MOFs based photocatalytic platforms for the decontamination of Cr(VI) and dyes from water.