State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; College of Civil Engineering, Fuzhou University, 350116 Fujian, PR China.
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China.
J Hazard Mater. 2022 Aug 5;435:129061. doi: 10.1016/j.jhazmat.2022.129061. Epub 2022 May 4.
The development of high efficient photocatalysts for antibiotics contamination in water remains a severe challenge. In this study, a novel step-scheme (S-scheme) photocatalytic heterojunction nanocomposites were fabricated from integrating AgCl nanoparticles on the MIL-100(Fe) octahedron surface through facile multi-stage stirring strategy. The S-scheme heterojunction structure in AgCl/MIL-100(Fe) (AM) nanocomposite provided a more rational utilization of electrons (e) and holes (h), accelerated the carrier transport at the junction interface, and enhanced the overall photocatalytic performance of nanomaterials. The visible-light-driven photocatalysts were used to degrade sulfamethazine (SMZ) which attained a high removal efficiency (99.9%). The reaction mechanisms of SMZ degradation in the AM photocatalytic system were explored by electron spin resonance (ESR) and active species capture experiments, which superoxide radical (•O), hydroxyl radical (•OH), and h performed as major roles. More importantly, the SMZ degradation pathway and toxicity assessment were proposed. There were four main pathways of SMZ degradation, including the processes of oxidation, hydroxylation, denitrification, and desulfonation. The toxicity of the final products in each pathway was lower than that of the parent according to the toxicity evaluation results. Therefore, this work might provide new insights into the environmentally-friendly photocatalytic processes of S-scheme AM nanocomposites for the efficient degradation of antibiotics pollutants.
用于水中抗生素污染的高效光催化剂的开发仍然是一个严峻的挑战。在这项研究中，通过简便的多步搅拌策略，在 MIL-100(Fe) 八面体表面上集成 AgCl 纳米粒子，制备了一种新型的阶梯式（S 型）光催化异质结纳米复合材料。AgCl/MIL-100(Fe)（AM）纳米复合材料中的 S 型异质结结构提供了更合理的电子（e）和空穴（h）利用，加速了载流子在结界面的传输，并增强了纳米材料的整体光催化性能。可见光驱动的光催化剂用于降解磺胺甲恶唑（SMZ），其去除效率达到 99.9%。通过电子顺磁共振（ESR）和活性物质捕获实验探索了 AM 光催化体系中 SMZ 降解的反应机制，超氧自由基（•O）、羟基自由基（•OH）和 h 起主要作用。更重要的是，提出了 SMZ 降解途径和毒性评估。SMZ 降解有四个主要途径，包括氧化、羟化、脱硝和脱硫过程。根据毒性评估结果，各途径中最终产物的毒性均低于母体。因此，这项工作可能为 S 型 AM 纳米复合材料的环保光催化过程提供新的见解，用于高效降解抗生素污染物。
