三维Ti/B-N-Gr/TiO2-x光电极对PFOA的富集及降解微观过程研究

The global pollution of PFOA has gradually become a potential risk for human health and environmental security, but the traditional chemical and biological methods show low efficiency in treatment of PFOA. In this project, the development of new adsorption-photoelectrocatalytic degradation method was carried out for handling PFOA treatment. By using titanium foam as substrate, TiO2-x nanocrystal modified B-N-Gr photoelectrode was fabricated and used in treatment of PFOA by combination of electro-enhanced adsorption and photoelectrocatalytic degradation in a single system. The in-situ polarized FTIR, electrochemical in-situ Raman spectroscopy were used for detecting the information of PFOA molecule that adsorbing and decomposing on the electrode surface. The time-resolution ESR, UPLC-MS, ion chromatography and TOC were used to detect the concentration and category of the reactive radicals, the intermediate and final materials, the concentration of F-, and the mineralization of PFOA for confirming the degradation mechanism of PFOA, and finally, provided a theoretical support for the development of adsorption-photoelectrocatalytic PFOA treatment technology.

全氟辛酸(PFOA) 所造成的全球性污染正日渐成为人体健康和环境安全的潜在危险，而传统化学和生物法难以有效处理PFOA，本项目针对这一问题开展PFOA的吸附富集-光电催化降解耦合处理新方法研究。以泡沫钛为基底制备具有光电催化功能的TiO2-x纳米晶修饰的三维B、N共掺杂石墨烯电极，研究其吸附及光电催化性能，实现单一系统中PFOA的电增强吸附富集、光电催化降解的有效结合。利用偏振红外光谱、电化学原位拉曼光谱等谱学技术，从分子层面原位研究PFOA在三维Ti/B-N-Gr/TiO2-x电极表面的吸附及催化降解微观过程，获取分子水平信息，揭示表面/界面调控的微观因素。利用时间分辨电子自旋共振、UPLC-MS、离子色谱、TOC分析光电催化反应过程中产生的活性自由基浓度及种类、中间产物、F-离子产生量、反应物的矿化率，揭示PFOA的光电催化降解机理，为发展PFOA富集-降解处理技术提供理论支持。

以全氟辛酸(PFOA)为代表的环境毒性污染物所造成的全球性污染正日渐成为人体健康和环境安全的潜在危险，本项目针对这一问题开展光电催化降解处理新方法研究。通过多种方式构建TiO2-x/BiVO4异质结、Pt/Co单原子修饰等方式，研究了提高缺陷TiO2-x纳米晶光电催化性能的方法，同时考察了氧缺陷作为单原子锚固位点对其催化活性及稳定性的影响机制，提出了利用TiO2-x晶体结构中原子级分散的氧缺陷位点锚固单原子的可行性；设计制备了基于石墨烯载体的三维多孔电极材料，考察了多维孔结构对电极催化活性和稳定性的影响机制，为制备高稳定性电催化阳极提供了新的思路，通过微乳法制备了Pt高度分散的Ti/Pt-RuO2-IrO2复合电极材料，考察了其催化性能和稳定性，并开发了工业规模生产方法，利用时间分辨电子自旋共振波谱、UPLC-MS-MS分析了PFOA等典型毒性有机污染物的分解中间产物、离子色谱检测最终F-离子的产生量、TOC分析反应物的矿化率，揭示了其光电催化分解过程机理。