当前位置: X-MOL 学术Environ. Sci. Technol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Activation of Peroxydisulfate on Carbon Nanotubes: Electron-Transfer Mechanism.
Environmental Science & Technology ( IF 10.8 ) Pub Date : 2019-11-22 , DOI: 10.1021/acs.est.9b05475
Wei Ren 1, 2 , Liangliang Xiong 1 , Xuehong Yuan 1 , Ziwei Yu 1 , Hui Zhang 1 , Xiaoguang Duan 2 , Shaobin Wang 2
Affiliation  

This study proposed an electrochemical technique for investigating the mechanism of nonradical oxidation of organics with peroxydisulfate (PDS) activated by carbon nanotubes (CNT). The electrochemical property of twelve phenolic compounds (PCs) was evaluated by their half-wave potentials, which were then correlated to their kinetic rate constants in the PDS/CNT system. Integrated with quantitative structure-activity relationships (QSARs), electron paramagnetic resonance (EPR), and radical scavenging tests, the nature of nonradical pathways of phenolic compound oxidation was unveiled to be an electron-transfer regime other than a singlet oxygenation process. The QSARs were established according to their standard electrode potentials, activation energy, and pre-exponential factor. A facile electrochemical analysis method (chronopotentiometry combined with chronoamperometry) was also employed to probe the mechanism, suggesting that PDS was catalyzed initially by CNT to form a CNT surface-confined and -activated PDS (CNT-PDS*) complex with a high redox potential. Then, the CNT-PDS* complex selectively abstracted electrons from the co-adsorbed PCs to initiate the oxidation. Finally, a comparison of PDS/CNT and graphite anodic oxidation under constant potentials was comprehensively analyzed to unveil the relative activity of the nonradical CNT-PDS* complex toward the oxidation of different PCs, which was found to be dependent on the oxidative potentials of the CNT-PDS* complex and the adsorbed organics.

中文翻译:

碳纳米管上过二硫酸盐的活化:电子转移机理。

这项研究提出了一种电化学技术,用于研究碳纳米管(CNT)活化的过氧二硫酸盐(PDS)对有机物进行非自由基氧化的机理。通过十二种酚类化合物的半波电势评估其电化学性质,然后将其与PDS / CNT系统中的动力学速率常数相关联。与定量结构-活性关系(QSAR),电子顺磁共振(EPR)和自由基清除测试相结合,酚类化合物氧化的非自由基途径的性质被揭示为一种电子转移机制,而不是单线态氧合过程。根据其标准电极电势,活化能和预指数因子建立QSAR。还采用了一种简便的电化学分析方法(计时电位法与计时电流法相结合)来探测该机理,这表明PDS最初被CNT催化形成了具有高氧化还原电位的CNT表面受限和活化的PDS(CNT-PDS *)络合物。 。然后,CNT-PDS *络合物选择性地从共吸附的PC中提取电子以引发氧化。最后,综合分析了在恒定电势下PDS / CNT和石墨阳极氧化的比较,揭示了非自由基CNT-PDS *配合物对不同PC氧化的相对活性,发现该活性取决于PDS / CNT的氧化电势。 CNT-PDS *复合物和吸附的有机物。这表明PDS最初被CNT催化,形成具有高氧化还原电位的CNT表面受限和活化的PDS(CNT-PDS *)络合物。然后,CNT-PDS *络合物选择性地从共吸附的PC中提取电子以引发氧化。最后,全面分析了在恒定电势下PDS / CNT和石墨阳极氧化的比较,揭示了非自由基CNT-PDS *配合物对不同PC氧化的相对活性,发现该活性取决于PDS / CNT的氧化电势。 CNT-PDS *复合物和吸附的有机物。这表明PDS最初被CNT催化,形成具有高氧化还原电位的CNT表面受限和活化的PDS(CNT-PDS *)络合物。然后,CNT-PDS *络合物选择性地从共吸附的PC中提取电子以引发氧化。最后,全面分析了在恒定电势下PDS / CNT和石墨阳极氧化的比较,揭示了非自由基CNT-PDS *配合物对不同PC氧化的相对活性,发现该活性取决于PDS / CNT的氧化电势。 CNT-PDS *复合物和吸附的有机物。
更新日期:2019-11-28
down
wechat
bug