Complete chromium removal via photocatalytic reduction and adsorption using bimetallic UiO-66(Zr/Al)

• Published in: Journal of environmental chemical engineering Vol. 12; no. 5; p. 113934
• Main Authors: Yu, Chao, Song, Chenxu, Zhang, Xianjin, Wang, Yanna, Lin, Jing, Huang, Yang, Guo, Zhonglu, Li, Chunsheng, Zhang, Yujie, Liu, Zhenya, Tang, Chengchun, Sun, Yan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2024
• Subjects: Adsorption; Chromium removal; Photocatalytic reduction; UiO-66(Zr/Al); Water purification; Chromium removal; Adsorption; Water purification; Photocatalytic reduction; UiO-66(Zr/Al)
• ISSN: 2213-3437
• DOI: 10.1016/j.jece.2024.113934

Photocatalytic reduction is a widely researched method for removing heavy metal ions from water. This study successfully synthesized Zr-based bimetallic UiO-66(Zr/Al) materials via a solvothermal method, incorporating aluminum (Al) into the Zr-UiO-66 lattice. Characterization confirmed successful Al(III) doping without altering the fundamental framework. Among the synthesized materials, UZA-6 exhibited remarkable photocatalytic activity, achieving a 99.25 % removal rate of hexavalent chromium (Cr(VI)) from water within 60 min under simulated solar irradiation. Additionally, the catalyst effectively adsorbed the reduced trivalent chromium (Cr(III)) and maintained a removal rate of 97.73 %, thereby achieving complete removal of Cr element in water. Photoluminescence and electrochemical analyses revealed that the enhanced photocatalytic performance was due to improved separation of photogenerated electron-hole pairs and facilitated charge transfer, attributed to Al doping. This research offers valuable insights into developing effective MOF-based catalysts for water purification, highlighting the potential of UZA-6 for efficiently removing both Cr(VI) and Cr(III) from contaminated water. [Display omitted] •UZA-6 catalyst achieves 99.25% Cr(VI) and 97.73% Cr(III) removal, ensuring comprehensive chromium removal.•Aluminum doping enhances photocatalytic activity by improving electron-hole separation and charge transfer.•UZA-6 shows robust Cr(VI) reduction, effective in diverse water purification scenarios across varying conditions.•Electrons and superoxide radicals drive Cr(VI) to Cr(III) reduction, revealing the mechanism of chromium removal.