Nano-porous bimetallic CuCo-MOF-74 with coordinatively unsaturated metal sites for peroxymonosulfate activation to eliminate organic pollutants: Performance and mechanism. (June 2021)

• Record Type: Journal Article
• Authors: Li, Huanxuan; Yang, Zongxiang; Lu, Shun; Su, Liya; Wang, Chunhui; Huang, Jingang; Zhou, Jie; Tang, Junhong; Huang, Mingzhi
• Is Part Of: Chemosphere. Volume 273(2021)
• Publication Date: 2021-06
• Subjects: CuCo-MOF-74 -- Peroxymonosulfate (PMS) -- Methylene blue (MB) -- DFT calculation -- Degradation mechanisms; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.129643
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The importance of clean water resources for maintaining sustainable development of society is self-evident. In this study, bimetallic metal-organic framework (CuCo-MOF-74) was synthesized and characterized by XRD, FT-IR, SEM, TEM, BET, and XPS techniques. The structural analysis results revealed that CuCo-MOF-74 was nano-porous materials with coordinatively unsaturated metal sites. With the addition of PMS, Cu1 Co1 -MOF-74 exhibited high activity for methylene blue (MB) removal (100% degradation) within 30 min under low 50 mg/L catalyst dosage. The effects of catalyst dosage, PMS dosage, MB concentration, initial pH, and common anions were evaluated. Quenching reactions and EPR studies revealed the coexistence of sulfate radical (SO4 − ), hydroxyl radical (· OH), and singlet oxygen ( 1 O2 ), which was attributed to the potential in-situ recycling of cobalt and copper species (Co(III)→Co(II), Cu(II)→Cu(I))). Fukui index ( f 0 ) and dual descriptor (Δ f ) by Density functional theory (DFT) calculations were applied to predict the most reactive sites of MB. Meanwhile, the possible degradation pathway of MB was proposed with the help of oxidative intermediates identified by UPLC-MS. Graphical abstract: Image 1 Highlights: Cu/Co bimetallic MOFs were fabricated through a facile hydrothermal route. 100% of MB was removed within 30 min in Cu1 Co1 -MOF-74/PMS system. · OH, SO4 . −, and 1 O2 coexisted and SO4 − played a dominant role in MB removal. The most reactive sites on MB molecule was predicted by DFT calculation. Intermediates and degradation pathways of MB were elucidated.