可见光铋系纳米异质结光催化剂的合成及其降解典型VOCs的机理

Volatile organic compounds (VOCs) are important precursors for the formation of atmospheric secondary pollutants via photochemical reactions and can contribute significantly to haze formation in China. This project aims to couple layer structure of bismuth-containing photocatalyst and nano-heterojunction in order to develop a (BiO)2CO3/Bi2O3 nano-heterojunction photocatalyst that features visible light absorption ability and high electron-hole separation efficiency. The heterojunction photocatalyst will be used to decompose VOCs under visible light irradiation. Visible-light sensitive nano-heterojunctions will be obtained under optimal conditions. The interface properties, surface properties and the role of reactive oxygen species (ROS) in the degradation of VOCs will be clarified. Degradation pathways of VOCs on (BiO)2CO3/Bi2O3 nano-heterojunction photocatalyst will further be elucidated. The relationship between photocatalytic activity of nano-heterojunction and corresponding composition, structure, interface and surface properties will also be discussed. The findings of this project will not only help develop environment-friendly nano-heterojunction photocatalyts, but also lay a theoretical foundation for their practical application in the remediation of severe air pollution in China.

挥发性有机物(VOCs)是大气光化学反应产生二次污染物的前体物，对区域灰霾现象的形成具有重要贡献。本项目拟将铋系层状材料和纳米异质结的优势结合，可控制备 (BiO)2CO3/Bi2O3纳米异质结光催化材料，拓展其可见光吸收能力，实现光生电子-空穴的有效分离，完成对大气典型VOCs的强化去除。通过优化材料合成工艺条件，制备高活性异质结，构建异质结光催化去除大气典型VOCs的降解途径，揭示异质结界面、表面性质以及活性氧物种在催化过程中的作用，运用多种现代分析手段研究其降解大气典型VOCs的机理，阐述Bi2O3/(BiO)2CO3纳米异质结的组成-结构-表/界面性质-催化性能之间的内在关联。研究成果不仅在基础科学问题方面有所突破，而且具有工程应用潜力，对发展环境友好的可见光纳米异质结光催化技术，改善我国空气质量具有重要的理论和现实意义。

设计和开发了一系列Bi系高效纳米异质结光催化材料，通过材料化学组成与微纳结构调控探究了光催化过程中催化材料的结构组成与目标气相污染物去除的“构-效”关系，揭示了其对光催化反应机制的影响规律，为异质结催化降解VOCs奠定了工作基础；基于外场观测与数值模拟，进行大气VOCs污染源解析、典型城市交通源VOCs排放特征研究、室内VOCs污染特征分析及其健康效应评估，为典型VOCs的控制提供科学依据；基于上述纳米异质结“构-效”关系研究及室内VOCs污染特征分析，设计和开发了非贵金属VOCs催化净化材料，并有效地将其应用于室内典型VOCs－甲醛的去除研究中，通过材料化学组成与微纳结构调控探究了催化过程中催化材料的结构组成与目标气相污染物去除的“构-效”关系，揭示了其对甲醛催化氧化反应机制的影响规律，为催化氧化降解VOCs提供了理论与技术支持，开拓了新思路。