Xu Meng, Yang Yunfei, Liu Peng, Wang Chuanjin, Wu Junshu, Wang Jinshu, Li Yongli, Li Hongyi
State Key Laboratory of Materials Low-Carbon Recycling, College of Materials Science & Engineering, Beijing University of Technology, Beijing 100124, China.
State Key Laboratory of Materials Low-Carbon Recycling, College of Materials Science & Engineering, Beijing University of Technology, Beijing 100124, China.
J Hazard Mater. 2025 Aug 15;494:138741. doi: 10.1016/j.jhazmat.2025.138741. Epub 2025 May 26.
To address the challenges of rapid Fe(II) consumption, high metal leaching, and limited activity in single-metal catalyst systems during peroxymonosulfate (PMS) activation, this study engineers a hierarchically structured MnSiO/Fe@C bimetallic catalyst. The catalyst integrates Fe nanospheres into vermiculite-derived layered manganese silicate, stabilized by a carbon network derived from pyrolyzed Fe-based metal-organic frameworks (Fe-MOFs). Theoretical calculations reveal that Fe serves as a sustained electron donor, enhancing Mn sites' electron density to drive Mn(II/III/IV) and Fe(II/III) valence cycling, accelerating the cleavage of O-O bonds in PMS (1.326 Å to 1.469 Å, DFT). Under optimized conditions (0.2 g/L catalyst, 0.2 g/L PMS, pH = 6.5), complete sulfamethoxazole (SMX, 20 mg/L) degradation is achieved within 60 min (k = 0.0583 min), with negligible Fe/Mn leaching (< 0.035 mg/L). Quenching experiments confirm singlet oxygen (O) as the dominant reactive species (72 % contribution), synergized by •OH and •SO via Fe oxidation and Mn valence transitions. The catalyst demonstrates robust adaptability in complex water matrices (HCO, HPO, SO, NO, Cl, CO, and humic acid) and real water samples (lake, well, and rainwater), achieving 100 % SMX removal and retaining 91.7 % activity after 4 cycles. Toxicity assessments reveal that the acute toxicity of degradation intermediates is reduced by 80 % compared to SMX, confirming environmental safety. This work provides mechanistic insights and technical references for the rational design of bimetallic catalysts and the effective treatment of antibiotic-contaminated water.
为应对过一硫酸盐（PMS）活化过程中单金属催化剂体系中铁（II）快速消耗、金属浸出率高和活性有限等挑战，本研究设计了一种具有分层结构的MnSiO/Fe@C双金属催化剂。该催化剂将铁纳米球整合到蛭石衍生的层状硅酸锰中，并由热解铁基金属有机框架（Fe-MOFs）衍生的碳网络稳定。理论计算表明，铁作为持续的电子供体，提高了锰位点的电子密度，从而驱动锰（II/III/IV）和铁（II/III）的价态循环，加速PMS中O-O键的断裂（从1.326 Å到1.469 Å，密度泛函理论）。在优化条件下（0.2 g/L催化剂，0.2 g/L PMS，pH = 6.5），60分钟内可实现磺胺甲恶唑（SMX，20 mg/L）的完全降解（k = 0.0583 min），铁/锰浸出可忽略不计（< 0.035 mg/L）。猝灭实验证实单线态氧（O）是主要的活性物种（贡献72%），通过铁氧化和锰价态转变与•OH和•SO协同作用。该催化剂在复杂水基质（HCO、HPO、SO、NO、Cl、CO和腐殖酸）和实际水样（湖水、井水和雨水）中表现出强大的适应性，实现了100%的SMX去除率，并且在4个循环后仍保留91.7%的活性。毒性评估表明，降解中间体的急性毒性比SMX降低了80%，证实了环境安全性。这项工作为双金属催化剂的合理设计和抗生素污染水的有效处理提供了机理见解和技术参考。
