PANI@CHNs双功能阴极氧还原活性调控及其选择性降解PFOS机理研究

全氟辛烷磺酸（PFOS）是分子结构稳定且难降解有机污染物，电化学法虽然能实现PFOS降解，但其氧还原活性和电极选择性差导致能耗高效率低。为此本项目研究开发高效产自由基并对PFOS选择性能优异的双功能氮掺杂碳纳米角电极（PANI@CHNs），基于氧还原活性强化研究，提出电子转移协同阴极氧还原产·OH降解的新思路。从电子转移和电极微界面调控耦合作用的角度，利用氮原子掺杂特性、氢键作用和CHNs曲率效应，来强化·OH的产生、PFOS的定向迁移及电子转移。通过研究氮原子位点特性和电极缺陷结构效应，揭示氧还原反应活性调控机制；探究氮掺杂与碳纳米角复合效应对·OH产生的强化作用，揭示碳纳米角曲率效应协助氢键作用对PFOS定向迁移和靶向吸附机制；考察PFOS在电极微界面上的电子转移-自由基反应过程，揭示PANI@CHNs选择性降PFOS新机制，为突破电化学降解PFOS瓶颈问题提供技术手段和奠定理论基础。

Perfluorooctane sulfonic acid (PFOS) is an organic pollutant with stable molecular structure and difficult to degrade. Although PFOS can be degraded by electrochemical method, its oxygen reduction activity and poor electrode selectivity lead to low energy consumption and high efficiency. For this reason, this project developed a bifunctional nitrogen-doped carbon nanohorn electrode (PANI@CHNs) with excellent performance for PFOS. Based on the enhancement of oxygen reduction activity, a new idea of electron transfer synergistic cathodic oxygen reduction ·OH degradation was proposed. From the perspective of electron transfer and electrode micro-interface regulation coupling, nitrogen atom doping characteristics, hydrogen bonding and CHNs curvature effect were used to enhance the generation of ·OH, PFOS directional migration and electron transfer. The regulation mechanism of oxygen reduction activity was revealed by studying the characteristics of nitrogen atom site and the effect of electrode defect structure. To explore the strengthening effect of the composite effect of nitrogen doping and carbon nanohorn on ·OH production, and reveal the mechanism of hydrogen bonding on PFOS directional migration and targeted adsorption assisted by the curvature effect of carbon nanohorn. The electron transfer - free radical reaction process of PFOS at the electrode micro-interface was investigated to reveal a new mechanism of PANI@CHNs selective degradation of PFOS, which provided a technical means and laid a theoretical foundation for breaking the bottleneck of electrochemical degradation of PFOS.