一维单晶{111}TiO2光电催化界面上邻苯二甲酸酯类污染物的增强吸附和优先氧化去除机制

Phthalate esters (PAEs) are highly toxic and chemically stable. They belong to typical endocrine disrupting chemicals and usually exist in the complex system. Efficient removal of highly toxic PAEs at their low concentrations in urban polluted waters remains a big challenge. This project proposes to utilize the Lewis acid-base interactions between the C=O of diester groups inside PAES and the photoelectrocatalytic surfaces, to achieve enhanced adsorption of PAEs on the photoelectrocatalytic interfaces, and eventually to primarily and rapidly remove these PAEs by means of photoelectrocatalytic approaches. A bi-functional interface with high catalytic oxidation capacity and strong sites of Lewis acid will be designed through constructing highly exposed single-crystal {111} facets and the corresponded one-dimensional TiO2 nanorod (NR). By use of such a photoanode material with highly dense charge transfer tunnels, the active adsorption mechanisms of PAEs will be clarified. The variation of adsorption mechanisms of different PAE molecules as well as their competitive adsorption mechanisms with other co-existing pollutants will be studied in detail. The photoelectrocatalytic degradation pathways (including degradation intermediates and efficiencies, mineralization rates, changes in the contents of intermediate products) of PAEs and the removal efficiency in real polluted water system will be demonstrated. This research thus develops a new method and provides the theoretical and practical guidance for efficiently removal of PAEs of the actual environment.

邻苯二甲酸酯类（PAEs）是一类毒性大、结构稳定、共存体系复杂的典型内分泌干扰物。本项目针对水体中PAEs污染严重，难以高效和深度去除的难题，基于PAEs分子的特征构型，提出利用邻位双酯基中C=O与具有Lewis酸性的光电催化表面形成酸碱配位作用原理，实现对PAEs的强化吸附和优先快速光电催化氧化去除。预期通过结构设计，构筑出具有高暴露{111}晶面、高密集电荷传输通道的单晶{111}TiO2纳米棒光电界面，赋予其强Lewis酸性位点和高效催化氧化活性的双重功能。阐明PAEs分子在光电界面上的特征吸附作用机制、不同PAEs分子间的强吸附、弱吸附规律以及PAEs与其他共存污染物的竞争吸附规律；全面评价光电催化氧化PAEs的效率，明晰降解中间产物、反应动力学过程和优先氧化降解机理；考察实际污染水体中PEAs的深度去除效果，为实际水环境中污染物的选择性富集和氧化降解提供理论和实践指导。

邻苯二甲酸酯类（PAEs）是一类毒性大、结构稳定、共存体系复杂的典型内分泌干扰物，在环境中具有潜在的致癌、致畸和致突变作用。本项目针对水体中PAEs污染严重，难以高效和深度去除的难题，基于PAEs分子的特征构型，提出利用邻位双酯基中C=O与具有Lewis酸性的光电催化表面形成酸碱配位作用原理，实现对PAEs的强化吸附和优先快速光电催化氧化去除。研究通过结构设计，构筑出具有高暴露{111}晶面、高密集电荷传输通道的单晶{111}TiO2纳米棒光电界面，获得同时具有强Lewis酸性位点和高效催化氧化活性的双重功能。通过吸附动力学曲线结合原位红外光谱（in situ ATR-FTIR）和密度泛函理论（DFT）计算结果，阐明PAEs分子在光电界面上的特征吸附作用机制以及PAEs与其他共存污染物的竞争吸附规律；通过荧光光谱（PL）和电子顺磁共振波谱（EPR）以及活性物种淬灭实验，证实{111}TiO2/Ti具有明显增强的光生电荷分离效率和显著提升的·OH产生量，并全面评价光电催化氧化PAEs的效率，结合中间产物、反应动力学过程的研究，提出了具体的优先氧化降解机理；最终考察了实际水样中PEAs的去除效果，为实际水环境中污染物的选择性富集和氧化降解提供理论和实践指导。