Key Laboratory for Colloid and Interface Chemistry, Key Laboratory of Special Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
Shandong Provincial Key Laboratory of Molecular Engineering, School of Chemistry and Pharmaceutical Engineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan 250353, China.
Ecotoxicol Environ Saf. 2023 Feb;251:114524. doi: 10.1016/j.ecoenv.2023.114524. Epub 2023 Jan 10.
MIL-101(Fe)-based catalysts have been widely used for degradation of organic pollutants based on peroxymonosulfate (PMS) activation. Hence, a facile calcination and hydrothermal method was used in this study to prepare a MIL-101(Fe)/g-CN composite catalyst with high activity and high stability for PMS activation to degrade tetracycline hydrochloride (TC) under visible-light irradiation. We clearly elucidated the mechanism involved in the MIL-101(Fe)/g-CN photo Fenton-catalyzed PMS activation process by separating the PMS activation and pollutant oxidation processes. The synergetic effects of MIL-101(Fe) and g-CN involved MIL-101(Fe) acting as an electron shuttle mediating electron transfer from the organic substrate to PMS, accompanied by redox cycling of the surface Fe(II)/Fe(III). Multiple experimental results indicated that PMS was bound to the surface of MIL-101(Fe)/g-CN during visible irradiation and generation of sulfate radicals (SO), hydroxyl radicals (•OH) and superoxide anion free radicals (•O) for the radical pathway and singlet oxygen (O) and holes (h) for the nonradical pathway. The major degradation pathways for TC can be described as demethylation, deamination, deamidation and carbonylation. This work provides valuable information and advances the fundamental understanding needed for design and syntheses of metal-free conjugated polymers modified by metal-organic frameworks for heterogeneous photo-Fenton reactions.
基于过一硫酸盐 (PMS) 活化，MIL-101(Fe) 基催化剂已被广泛用于降解有机污染物。因此，本研究采用简便的煅烧和水热法制备了一种具有高活性和高稳定性的 MIL-101(Fe)/g-CN 复合催化剂，用于可见光照射下 PMS 活化降解盐酸四环素 (TC)。我们通过分离 PMS 活化和污染物氧化过程，清楚地阐明了 MIL-101(Fe)/g-CN 光芬顿催化 PMS 活化过程中涉及的机制。MIL-101(Fe) 和 g-CN 的协同作用包括 MIL-101(Fe) 作为电子穿梭体将电子从有机底物转移到 PMS，同时表面 Fe(II)/Fe(III) 发生氧化还原循环。多项实验结果表明，在可见光照射下，PMS 与 MIL-101(Fe)/g-CN 表面结合，并通过自由基途径生成硫酸根自由基 (SO)、羟基自由基 (•OH) 和超氧阴离子自由基 (•O)，以及通过非自由基途径生成单线态氧 (O) 和空穴 (h)。TC 的主要降解途径可以描述为脱甲基、脱氨、脱酰胺和羰基化。这项工作提供了有价值的信息，并推进了设计和合成用于非均相光芬顿反应的无金属共轭聚合物修饰金属-有机骨架的基础理解。
