理论与实验研究典型VOCs在Au/TiO2@CNTs上的吸附、可见光催化降解及其协同机理

本项目将碳纳米管(CNTs)对低浓度挥发性有机物(VOCs)有效吸附富集作用和Au/TiO2可见光催化降解矿化作用相结合,研制一种适合于低浓度VOCs降解的高效环境友好型Au/TiO2@CNTs复合光催化剂。采用典型VOCs程序升温吸附-脱附法、原位傅立叶-红外分析与理论计算模拟相结合的手段，研究典型VOCs在CNTs和Au/TiO2@CNTs上的界面吸附、催化剂表面结合形态和界面迁移等；探讨典型VOCs在Au/TiO2/CNTs上吸附和降解动力学，研究其吸附机理与降解反应途径，并结合理论模拟数据对其吸附与降解动力学及其机理进行验证；探讨催化剂结构特征、吸附和光催化降解效率之间关系，阐明CNTs负载对VOCs降解效率提高的本质原因。项目的成功实施对于了解VOCs在全球气候变化和环境地球化学过程中活性矿物界面吸附、迁移转化及降解过程及脱毒机制、提高人体健康水平，均具有重要理论与现实意义。

This project aims to develop a novel environmental-friendly Au/titanium dioxide@carbon nanotubes (Au/TiO2/CNTs) composite photocatalyst capable of effective adsorption and subsequently rapid degradation as well as mineralization of low concentration atmospheric volatile organic compounds (VOCs). CNTs have relatively high adsorption capacities and will adsorb and concentrate atmospheric VOCs even in the extremely low concentration, and Au/TiO2 has the visible hight photocatalytic capability to decompose VOCs. The adsorption characteristic of VOCs onto the interface of CNTs as well as Au/TiO2@CNTs photocatalyst, the surface combination morphology as well as the interfacial transfer and the adsorption mechanism of VOCs onto the composite photocatalyst surface will be systematically probed by using temperature-programmed desorption of VOCs, in situ analysis by Fourier transform -infrared spectrometer (FT-IR) and the theoretical modeling. Furthermore, the photocatalytic degradation kinetics of VOCs onto the Au/TiO2@CNTs surface will be investigated, and both the theoretically calculated values and the degradation intermediates obtained from GC-MS will be collectively utilized to illustrate the mechanistic aspects of visible light photocatalytic degradation process. The relationship between the structure of photocatalyst, the adsorption capacity of the catalyst and the photocatalytic degradation efficiency, as well as the nature why the photocatalytic degradation efficiency of VOCs is enhanced by combining Au/TiO2 with CNTs together will be also investigated. The outcome of this project will certainly advance the fundamental knowledge of related disciplines. It will significantly help us to full insight into the role of VOCs in the global climate change and the environmental geochemical cycle, as well as the role in the processes of the adsorption, transformation and degradation of VOCs onto the environmental mineral surfaces in field sites. Particularly, the success of the proposed project will also bring considerable socioeconomic benefit to human beings since the project concerns a vitally important field - waste gas treatment.