Abstract:

In Fenton-like reactions, the chemical environment surrounding the active sites of iron-based catalysts profoundly influences the mechanism of the reaction system. In light of this impact, this study functionalized the surface of the two-dimensional layered iron-based material FeOCl with the electron-withdrawing organic compound nitroterephthalic acid (NTPA) to synthesize an easily separable and recoverable iron-based catalyst (NTPA-FeOCl). The morphology and microstructure of the catalyst were characterized using SEM, XRD, XPS and FTIR. The catalytic performance was assessed by activating persulfate (PMS) to degrade acetaminophen (ACT). Furthermore, by controlling experimental variables and introducing a variety of antibiotics, endocrine disruptors, and personal care product organic pollutants, the study systematically examined the efficacy and characteristics of the NTPA-FeOCl activated PMS system in degrading organic compounds. The results demonstrated that under the conditions of 0.2g/L NTPA-FeOCl, 2mmol/L PMS concentration, and an initial pH of 7.0, ACT (0.1mmol/L) was degraded by 99.69% within 30 minutes, exhibiting selectivity in the degradation of different organic substances. Quenching experiments revealed that the degradation of ACT within the system was mediated by both radicals and selective oxidative activity non-radicals of the system, with singlet oxygen being the predominant reactive oxygen species, thereby further the towards electron-rich organic compounds. After modification with NTPA, some Fe atoms on the FeOCl surface were in an electron-deficient state, which attracted the terminal O atoms of PMS for reaction, consequently enhancing the generation of singlet oxygen within the system and fortifying the non-radical pathway for organic degradation.

Key words: Fenton-like reaction, FeOCl, peroxymonosulfate, singlet oxygen, non-radical pathways

摘要：

类芬顿反应中，铁基催化剂活性中心所在的化学环境对体系的反应机理具有深远的影响。基于该影响，本研究通过使用吸电子有机物硝基对苯二甲酸（NTPA）对二维层状铁基材料FeOCl表面进行修饰，制备出易分离回收的铁基催化剂（NTPA-FeOCl），利用SEM、XRD、XPS、FTIR表征分析其形貌和微观结构，通过活化过一硫酸盐（PMS）降解对乙酰氨基酚（ACT），来评价其催化性能。另外，通过控制实验变量和引入不同抗生素、内分泌干扰物、护理品类有机污染物，系统考察了NTPA-FeOCl活化PMS体系降解有机物的效能、特点。结果表明，在NTPA-FeOCl投加量0.2g/L，PMS浓度2mmol/L，以及初始pH=7.0的条件下，ACT（0.1mmol/L）可在30min内降解99.69%，且体系对不同有机物的降解表现出选择性。淬灭实验结果表明，体系内ACT的降解由自由基和非自由基共同完成，但单线氧是主导活性氧物种，因此进一步证明了体系对富电子型有机物的选择氧化性。NTPA修饰后，FeOCl表面部分Fe原子呈现缺电子状态，吸引PMS端头O原子发生反应，从而提高了体系内单线氧的生成量，强化了有机物降解的非自由基路径。

关键词: 类芬顿, 氧基氯化铁, 过一硫酸盐, 单线氧, 非自由基路径