具有手性识别功能的高选择性光电催化电极的构筑与作用机制

Due to the low selectivity of photoelectrocatalysis on removing target pollutant in complex system, a novel oxidation technique for chiral recognition with high photoelectrocatalytic selectivity is proposed in this project. According to the idea of "controllability of microstructure- function of chiral recognition- selectivity of photoelectrocatalytic oxidation", high-resolution imprint and 1D single-crystal ZnO/boron-doped diamond film (BDD) photoelectric electrodes with high selectivity are constructed and prepared. ZnO has one-dimensional controlled, vertically aligned and single-crystal rigid surface, which is prefer to gain clear imprinted locus and reproducible chiral recognition. While BDD possesses the characteristics of wide potential window, low surface adsorption and chemically inertness, which is helpful to carry out the electrochemical control and reduce the adsorption of non-target pollutants. In addition, Combing p type semiconductor surface of BDD with n type single-crystal ZnO photocatalyst could form efficient p-n junction on photoelectric interface, which is favorable for directionally fast electron transmission. This construction ingeniously combined with chiral recognition, electrochemical controllability and photocatalytic oxidation on the same electrode surface, finally to achieve integrated functions and obtain highly photoelectrocatalytic selectivity and efficiently photoelectrocatalytic performance for those enantiomers pollutants with similar structure but different toxicity. This research can reveal chiral recognized mechanism of photoelectric electrode with high-resolution imprint and clarify the relationship between structure and function of electrode. This project containing new idea can offer a novel method for selective photoelectrocatalysis pollutants.

针对光电催化氧化在复杂污染体系处理中选择性低的局限性，提出了一种具有手性识别功能的高选择性光电催化氧化降解新方法。从"微结构调控-手性识别功能-选择性光电催化氧化"思想出发，设计制备出高印迹表达的1D单晶ZnO/掺硼金刚石膜BDD选择性光电功能电极。ZnO一维可控、规整有序、单晶刚性的结构表面有利于原位构筑获得印迹位点清晰、重现性好的手性识别能力；BDD电势窗口宽、表面吸附弱、化学惰性的特征，有助于进行电化学调控，并降低非目标污染分子吸附；且p型BDD电化学表面与n型ZnO单晶光催化剂可形成高效p-n结光电界面，有利于电子定向快速传输。这一构筑将手性分子识别、电化学调控、光催化氧化三者在同一电极表面上巧妙结合，实现一体化功能，获得对结构非常相似、毒性差异大的手性污染物对映体的高选择性、高效光电催化功效。研究揭示其手性识别原理与构效机制。这一思想新颖，将开辟一种选择性光电催化污染控制新方法。

本项目在国家自然科学基金的资助下，从“微结构调控-手性识别功能-选择性光电催化氧化降解手性污染物”思想出发，制备得到了具有手性识别功能的1D六方单晶ZnO、1D四方 (001) 晶面TiO2等多种选择性光电催化电极新材料。研究发现，相比于多晶表面，有序单晶无机氧化物半导体刚性表面构筑的分子印迹位点识别表达更清晰，重现好，目标污染物的非特征性吸附大大下降，光电选择性氧化的程度显著增强。研究揭示了方法的选择性机制，并成功应用于苯酚/对羟基苯甲酸共存体系、L/D-苯丙氨酸手性对映体、手性农药、2，4-滴丙酸(DCPP)外消旋体等化学性质、分子结构相近的有机小分子污染物和手性污染物的高选择性识别与可控氧化降解。首次实现了在单晶手性S-TiO2人工光电催化材料表面，对无活性(S)-DCPP手性农药对映体的优先快速选择性氧化去除。此外，基于单晶光电催化剂表面分子印迹识别和核酸适配体特异性识别方法，研制出一系列具有高灵敏、选择专一性的17-雌二醇、双酚A以及啶虫脒农药等特征环境污染物传感器，非常适合应用于复杂水环境样品的检测。在国际有影响的环境化学学术期刊上发表SCI论文32篇，包括2篇ES&T、4篇Appl. Cataly. B: Environ.、3篇 J. Phys. Chem. C、1篇Green Chem.等期刊论文，获得授权专利5项。