光电催化协同去污与制氢新型功能构筑的设计与机理研究

This project intends to design novel metal oxides nanotube array-based heterojunction hybrid photoelectrocatalytic system. Induced by external electric field, the photogenerated electrons and holes could be utilized for organic-contaminants oxidizing degradation and hydrogen evolution at cathode and anode, respectively, for achieving photoelectrocatalysis-induced synchronous decontamination and hydrogen evolution. Various routes, including increasing the interaction between the substrate and the nanotube arrays, achieving higher crystallinity or single-crystallization of the body of nanotubes, forming heterojunction photocatalytic hybrid system on the surface the nanotube walls, modifying the wall with conductive carbon-based materials (graphene, fullerenes etc.) and other ways, are proposed with the aim of improving the transfer rate of photogenerated electrons, producing higher separation efficiency of electrons and holes, broadening the light response region, and enhancing the light absorption efficiency and quantum efficiency. In-situ characterization and other means will be explored to detect the charge transfer process both in the body and on the surface of the photoelectrocatalytic hybrid system. LC-MS chromatographic will be used to detect the intermediates of the degraded organic pollutants for investigating effect of the organic species, molecular structures, and concentration of the organic pollutants to be degraded on hydrogen evolution performance. Electron paramagnetic resonance spectroscopy (EPR) and fluorescence spectroscopy will be used to detect the hydroxyl radicals involved from photogenerated holes under different conditions. Based on the above analysis, structure-activity relationship of the photoelectrocatalytic system will be clarified for designing novel, efficient, and stable photoelectrocatalytic construct to be utilized in resourcing polluted water.

本项目拟设计新型金属氧化物纳米管阵列异质结杂化光电催化体系，在电场诱导下，使光生电子与空穴分别于阴极和阳极氧化降解有机污染物与析氢，实现光电催化同步去污与制氢。通过增强纳米管阵列与基底相互作用，纳米管本体结晶度提高或单晶化，纳米管管壁表面形成异质结光催化杂化体系和导电碳基材料（石墨烯、富勒烯等）的修饰等途径，提高光生电子传输速率，促成电子与空穴有效分离，拓宽体系的光响应范围，提高光的吸收效率与量子效率。结合原位表征等手段，探究光电催化杂化体系体相与表面电荷转移过程；采用液质联用色谱检测有机污染物降解的中间产物，阐述有机物种类、分子结构、浓度等对协同产氢的影响机制；采用电子顺磁共振波谱仪和荧光光谱检测光电催化剂在不同条件下光生空穴转化为羟基自由基的情况。基于以上分析，阐明光电催化体系的构效关系，设计出高效、稳定的新型光电催化构筑应用于污水的资源化。

在自然科学基金（批准号: 21876113）的资助下，通过项目组成员的共同努力，申请书中所列研究计划的要点已基本完成。本项目针对水体污染治理协同绿色清洁能源生产过程的关键问题，设计制备了一系列宽光谱响应、高效的金属氧化物纳米管阵列异质结电极(g-C3N4/rGO/Ni foam、多孔珊瑚状WO3/W、CoOx/Cu foam、Pt/Si-NWs&TiO2-NTAs等)，并构建了协同处理污染物与制氢的高效光电催化体系及相关反应器，实现了依靠光电催化技术的高效协同污染物处理与制氢。结合原位表征等手段，阐明了污染物降解与分解水析氢的协同促进效应在光电催化系统内的相互增强机制，建立了低成本、大比表面积、宽光谱响应的高效光电催化新体系，为重污染区域重点行业发展提供环保技术支撑，为实现同步处理有机污染物与清洁能源生产提供基础和保障。该研究丰富了光电催化治理水体污染物及产氢基础研究，推动了催化材料和环境学科的发展。本项目已发表相关SCI论文30篇，IF > 5的文章28篇，已申请专利6项，其中已授权1项。共培养了10名硕士研究生。本项目的实施为推广光电催化在环境净化领域的应用做出了重要贡献，提高了科研能力和学术水平，促进了学科和人才培养的发展。