Tang Cilai, Lin Bingfeng, Niu Huibin, Zheng Kai, Liu Yongxuan, Chen Xueli, Zhong Keyuan, Zhu Rong, Chen Yonglin, Li Haitao, Wu Yonghong, Huang Yingping, Yuan Xi
School of Geography and Environmental Engineering, Gannan Normal University, Ganzhou 341000 Jiangxi, China.
College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang 443002 Hubei, China.
J Colloid Interface Sci. 2025 Nov 15;698:138062. doi: 10.1016/j.jcis.2025.138062. Epub 2025 Jun 2.
Zeolitic imidazolate framework (ZIF-67) derivatives have emerged as promising Fenton-like catalysts due to their tunable structural regulation and multi-element composition. However, the rational design of ZIF-67-derived materials with highly exposed metal active sites remains a critical challenge. Here, a carbon nitride (g-CN) supported ZIF-67 derivatives (Co-GNC), featuring highly dispersed cobalt (Co) nanoparticles, was developed for peroxymonosulfate (PMS) activation to degrade sulfamethoxazole (SMX). The physicochemical properties of the Co-GNC were systematically characterized using advanced analytical techniques. Batch experiments were conducted to investigate the effects of various parameters on SMX removal efficiency. The results revealed that Co-GNC-0.6, with an optimal g-CN loading (0.6 g), exhibited exceptional catalytic performance. It achieved 82.86 % SMX removal (k = 0.2434 min) with 10 min. The negative influence of coexisting ions on SMX removal followed the order: NO < NH < Cl < SO < HPO < HCO. Co-GNC-0.6 demonstrated remarkable stability and recyclability for SMX removal, and demonstrated broad-spectrum applicability by removing over 70 % of other antibiotics (e.g., tetracycline, levofloxacin, and ciprofloxacin). Quenching experiments, electron paramagnetic resonance (EPR), and electrochemical analyses revealed that SMX degradation involved a synergistic mechanism of free radicals (O), non-free radicals (O), and direct electron transfer, achieving 68.5 % total organic carbon (TOC) removal. The large specific surface area of g-CN facilitated initial adsorption of SMX onto the catalyst surface. Moreover, g-CN inhibited agglomeration of Co nanoparticles, ensuring high dispersion and exposing more active sites for PMS activation. Furthermore, g-CN increased the charge density of the catalyst and reduced charge transfer resistance, thereby accelerating electron transfer. Density functional theory (DFT) calculations confirmed that g-CN enhanced PMS adsorption on Co-GNC-0.6 and significantly promoted interfacial electron transfer. Based on identified SMX degradation intermediates, four potential degradation pathways were proposed. Environmental Chemistry and SAR Tool (ECOSAR) prediction indicated a significant reduction in the biological toxicity of degradation products. This study provides a novel strategy for designing highly efficient PMS activators with optimized metal dispersion and active site exposure for rapid removal of SMX.
沸石咪唑酯骨架（ZIF-67）衍生物因其可调控的结构和多元素组成，已成为颇具潜力的类芬顿催化剂。然而，合理设计具有高度暴露金属活性位点的ZIF-67衍生材料仍是一项严峻挑战。在此，开发了一种负载有氮化碳（g-CN）的ZIF-67衍生物（Co-GNC），其具有高度分散的钴（Co）纳米颗粒，用于活化过一硫酸盐（PMS）以降解磺胺甲恶唑（SMX）。采用先进分析技术对Co-GNC的物理化学性质进行了系统表征。进行了批量实验以研究各种参数对SMX去除效率的影响。结果表明，g-CN负载量为最佳值（0.6 g）的Co-GNC-0.6表现出卓越的催化性能。在10分钟内实现了82.86%的SMX去除率（k = 0.2434 min⁻¹）。共存离子对SMX去除的负面影响顺序为：NO₃⁻ < NH₄⁺ < Cl⁻ < SO₄²⁻ < HPO₄²⁻ < HCO₃⁻。Co-GNC-0.6在去除SMX方面表现出显著的稳定性和可回收性，并且通过去除超过70%的其他抗生素（如四环素、左氧氟沙星和环丙沙星）证明了其广谱适用性。猝灭实验、电子顺磁共振（EPR）和电化学分析表明，SMX降解涉及自由基（·OH）、非自由基（¹O₂）和直接电子转移的协同机制，实现了68.5%的总有机碳（TOC）去除。g-CN的大比表面积促进了SMX在催化剂表面的初始吸附。此外，g-CN抑制了Co纳米颗粒的团聚，确保了高分散性并暴露出更多用于PMS活化的活性位点。此外，g-CN增加了催化剂的电荷密度并降低了电荷转移电阻，从而加速了电子转移。密度泛函理论（DFT）计算证实，g-CN增强了PMS在Co-GNC-0.6上的吸附并显著促进了界面电子转移。基于鉴定出的SMX降解中间体，提出了四条潜在的降解途径。环境化学与结构活性关系预测工具（ECOSAR）预测表明降解产物的生物毒性显著降低。本研究为设计具有优化金属分散和活性位点暴露的高效PMS活化剂以快速去除SMX提供了一种新策略。
