摘要
      环保型Fe@nitrogen-doped碳纳米复合催化剂(Fe@N-CNs)以羧甲基壳聚糖（CMC）水凝胶为模板，通过简单而经济的工艺制备，同时实现Fe锚定和N掺杂，以激活过一硫酸盐（PMS），从而有效降解磺胺甲恶唑（SMX）。的“核-壳”结构Fe@N-CNs显示被鉴定为Fe3C和Fe3N的Fe纳米颗粒被封装在氮掺杂的碳纳米片中。FexNy位点的形成和从CMC获得的高含量石墨N促进了催化反应。具有在不到10分钟内实现SMX完全降解的优异催化活性，Fe@N-CNs/PMS系统在宽pH范围（3.0–9.0）和高盐度条件下也表现出稳定的催化降解效率。单线态氧被确定为催化氧化中的主要反应物种，并在非自由基途径中发挥着至关重要的作用。SMX潜在的降解途径和机制Fe@N-CNs/根据DFT计算和产物检测结果，提出了PMS反应体系。定量构效关系（QSAR）预测验证了SMX降解产物毒性的有效消除。此外Fe@N-CNs/PMS系统也被证实对抗生素抗性细菌（ARB）和抗生素抗性基因（ARGs）的灭活有效。
Abstract
An environmentally friendly Fe@nitrogen-doped carbon nanocomposite catalyst (Fe@N-CNs) was prepared via a facile and economical process using carboxymethyl chitosan (CMCs) hydrogel as a template to achieve Fe-anchoring and N-doping simultaneously for peroxymonosulfate (PMS) activation to efficiently degrade sulfamethoxazole (SMX). The “core–shell” structure of Fe@N-CNs displayed that Fe nanoparticles identified as Fe3C and Fe3N were encapsulated in nitrogen-doped carbon nanosheets. The formation of FexNy sites and the high content of graphitic N obtained from CMCs facilitated the catalytic reaction. With excellent catalytic activity to achieve complete degradation of SMX in less than 10 min, Fe@N-CNs/PMS system also exhibited stable catalytic degradation efficiency over a wide pH range (3.0–9.0) and under high-salinity conditions. Singlet oxygen was identified as the dominant reactive species in catalytic oxidation and played a vital role in the non-radical pathway. The potential SMX degradation pathway and mechanism in the Fe@N-CNs/PMS reaction system were proposed according to DFT calculations and product detection results. Quantitative structure–activity relationship (QSAR) prediction verified the efficient elimination of SMX degradation products toxicity. Moreover, the Fe@N-CNs/PMS system was also confirmed to be effective towards the inactivation of antibiotic-resistant bacteria (ARB) and antibiotics resistance genes (ARGs).

https://www.sciencedirect.com/science/article/abs/pii/S1385894722012840