Chongqing Key Laboratory of Environmental Materials & Remediation Technologies, College of Chemistry and Environmental Engineering, Chongqing University of Arts and Sciences, Yongchuan, 402160, China; School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044, China.
Chongqing Key Laboratory of Environmental Materials & Remediation Technologies, College of Chemistry and Environmental Engineering, Chongqing University of Arts and Sciences, Yongchuan, 402160, China.
Environ Res. 2022 Apr 15;206:112301. doi: 10.1016/j.envres.2021.112301. Epub 2021 Oct 29.
The sluggish Ni(II)/Ni(III) redox cycle does not benefit perxymonosulfate (PMS) activation for recalcitrant pollutant degradation. To solve this problem, a heterogeneous catalyst, CuNiO/SBA-15 (CNS), was constructed to activate PMS for decomposing two sulfonamide antibiotics, sulfachlorpyridazine (SACP) and sulfapyridine (SAP). SACP and SAP were completely degraded over CuNiO/SBA-15/PMS (CNSP) after 90 min. O was the dominant active species involved in the degradation of SACP and SAP. Structural analysis and elemental valence state observations indicated that Cu(Ⅰ) provided electrons through Cu-O-Ni bonds to realize the charge compensation for Ni(Ⅲ) in the CNSP system. Thus, the in situ Cu(I)/Cu(II) promoting the Ni(II)/Ni(III) cycle could accelerate the PMS activation. This work provides new insights into the electron transfer between transition metals and the charge compensation mechanism for PMS activation. The degradation mechanism was proposed based on the XPS results before and after the reaction, a radical quenching test, and an EPR test. Combined with the SACP and SAP degradation intermediates identified by LC-MS, we suggest that the choice of treatment process depends on the occurrence of a steric hindrance effect between the molecular structure of the degradation target and free radicals.
缓慢的 Ni(II)/Ni(III) 氧化还原循环不利于过一硫酸盐 (PMS) 激活难降解污染物。为了解决这个问题，构建了一种非均相催化剂 CuNiO/SBA-15 (CNS)，用于激活 PMS 分解两种磺胺类抗生素，磺胺氯哒嗪 (SACP) 和磺胺嘧啶 (SAP)。SACP 和 SAP 在 90 分钟内完全通过 CuNiO/SBA-15/PMS (CNSP) 降解。O 是参与 SACP 和 SAP 降解的主要活性物质。结构分析和元素价态观察表明，Cu(Ⅰ) 通过 Cu-O-Ni 键提供电子，实现 CNSP 体系中 Ni(Ⅲ)的电荷补偿。因此，原位 Cu(I)/Cu(II) 促进 Ni(II)/Ni(III) 循环可以加速 PMS 的激活。这项工作为过渡金属之间的电子转移和 PMS 激活的电荷补偿机制提供了新的见解。根据反应前后的 XPS 结果、自由基猝灭试验和 EPR 试验，提出了降解机制。结合 LC-MS 鉴定的 SACP 和 SAP 降解中间体，我们建议处理过程的选择取决于降解目标的分子结构与自由基之间是否存在空间位阻效应。
