Abstract：
Sulfamethoxazole (SMX), a widely utilized antibiotic, was continually detected in the environment, causing serious risks to aquatic ecology and water security. In this study, carbon nanotubes (CNTs) with abundant defects were developed by argon plasma-etching technology to enhance the activation of persulfate (PS, including peroxymonosulfate (PMS) and peroxydisulfate (PDS)) for SMX degradation while reducing environmental toxicity. Obviously, the increase of ID/IG value from 0.980 to 1.333 indicated that Ar plasma-etching successfully introduced rich defects into CNTs. Of note, Ar-90-CNT, whose Ar plasma-etching time was 90 min with optimum catalytic performance, exhibited a significant discrepancy between PMS activation and PDS activation. Interestingly, though the Ar-90-CNT/PDS system (kobs = 0.0332 min-1) was more efficient in SMX elimination than the Ar-90-CNT/PMS system (kobs = 0.0190 min-1), Ar plasma-etching treatment had no discernible enhancement in the catalytic efficiency of MWCNT for PDS activation. Then the discrepancy on activation mechanism between PMS and PDS was methodically investigated through quenching experiments, electron spin resonance (ESR), chemical probes, electrochemical measurements and theoretical calculations, and the findings unraveled that the created vacancy defects were the ruling active sites for the production of dominated singlet oxygen (1O2) in the Ar-90-CNT/PMS system to degrade SMX, while the electron transfer pathway (ETP), originated from PDS activation by the inherent edge defects, was the central pathway for SMX removal in the Ar-90-CNT/PDS system. Based on the toxicity test of Microcystis aeruginosa, the Ar-90-CNT/PDS system was more effective in alleviating environmental toxicity during SMX degradation. These findings not only provide insights into the discrepancy between PMS activation and PDS activation via carbon-based materials with controlled defects regulated by the plasma-etching strategy, but also efficiently degrade sulfonamide antibiotics and reduce the toxicity of their products.
摘要：
磺胺甲恶唑(SMX),一种广泛使用的抗生素，在环境中不断检测到，对水生生态和水安全造成严重风险。在这项研究中,通过氩等离子体蚀刻技术开发了具有丰富缺陷的碳纳米管(CNTs)，以增强过硫酸盐的活化(PS，包括过氧单硫酸盐（PMS）和过氧二硫酸盐（PDS））用于SMX降解，同时降低环境毒性。显然,ID/IG值从0.980增加到1.333表明Ar等离子体蚀刻成功地将丰富的缺陷引入到CNT中。值得注意的是，Ar-90-CNT,Ar等离子体刻蚀时间为90min，催化性能最佳，PMS激活和PDS激活之间存在显着差异。有趣的是,尽管Ar-90-CNT/PDS系统（kobs=0.0332min-1）在消除SMX方面比Ar-90-CNT/PMS系统（kobs=0.0190min-1）更有效，Ar等离子体蚀刻处理对于PDS活化的MWCNT的催化效率没有明显的增强。然后通过猝灭实验系统地研究了PMS和PDS之间活化机理的差异。电子自旋共振（ESR），化学探针,电化学测量和理论计算，发现揭示了产生的空位缺陷是Ar-90-CNT/PMS系统中产生主要单线态氧（1O2）以降解SMX的主要活性位点，而电子转移途径(ETP)，源于固有边缘缺陷的PDS激活，是Ar-90-CNT/PDS系统中SMX去除的中心途径。根据铜绿微囊藻的毒性试验,Ar-90-CNT/PDS系统在减轻SMX降解过程中的环境毒性方面更有效。这些发现不仅提供了对PMS活化和PDS活化之间的差异的见解，通过具有受控缺陷的碳基材料由等离子体蚀刻策略调节，而且还能有效降解磺胺类抗生素并降低其产品的毒性。
