理论化学计算研究g-C3N4量子点/石墨烯复合体系:原位VOCs探测及其可见光催化降解

Volatile Organic Compounds (VOCs) are major pollution components in air. Effective, low cost treatment of VOCs is an important topic of environment research area. Based on the excellent properties of graphite carbon nitride (g-C3N4) on the photocatalysis under visible light irradiation and unique properties of graphene on gas sensors, this project will adopt theoretical chemistry calculations to study g-C3N4 quantum dots/graphene system for in-situ VOCs detection and treatment through photocatalysis under visible light irradiation. Based on the investigation of the adsorption of several typical VOCs molecules on the surface of the composition, different methods will be proposed to optimise the sensing performance for VOCs. At the meantime, different methods will be adopted to tune the band structure of g-C3N4 quantum dots, in order to activate g-C3N4 under visible light and obtain OH• and O2•- radicals for the photodegradation of VOCs. This study is the first time to consider g-C3N4 as the main photocatalyst for VOCs treatment, while the combination of g-C3N4 and graphene to realize in-situ detection and treatment also provides a new ideal for VOCs treatment. The success of this project will facilitate the development of high-performance VOCs sensors and g-C3N4 photocatalysts, and thus provide solid theoretical foundation for the effective, low cost treatment of VOCs.

挥发性有机化合物（VOCs）是目前空气污染物的主要成分之一，其高效、低耗的处理技术是目前环境领域一个重要课题。基于类石墨氮化碳g-C3N4在可见光催化方面的优良特性和石墨烯在气体探测方面的绝佳性能，本项目利用理论化学计算研究g-C3N4量子点/石墨烯复合体系原位VOCs分子探测及其可见光催化降解过程。通过研究几种典型VOCs分子在该体系上吸附，提出有效的调控方法，优化该体系对VOCs分子的探测性能。同时利用多种手段调控g-C3N4量子点的能带结构，使其能在可见光下激发产生OH•和O2•-自由基，从而有效降解VOCs分子。本研究首次考虑应用g-C3N4做为VOCs处理的主要催化剂，同时结合石墨烯实现原位VOCs分子探测及其可见光催化降解。成功实施该项目可以有效促进高性能VOCs气体探测器和g-C3N4可见光催化剂的设计开发，从而为高效、低耗处理VOCs提供坚实的理论基础。

本项目利用理论化学计算研究g-C3N4量子点/石墨烯复合体系原位VOCs分子吸附、探测及其可见光催化降解过程。通过研究几种典型VOCs分子在该体系上吸附，提出有效的调控方法，优化该体系对VOCs分子的探测性能。同时利用多种手段调控g-C3N4量子点的能带结构，使其能在可见光下激发产生OH•和O2•-自由基，从而有效降解VOCs分子。通过本项目确定了g-C3N4量子点/石墨烯复合体系结构，并研究了复合体系的各种性质和单一组元、及相关体系的性质的对比，从气体吸附性能、能带结构、光吸收性能、以及自由基产生的能力等方面研究了VOCs的吸附、探测、及光催化降解性能及机理。本项目的实施圆满完成了预定的研究目标，提出了多个相关的催化剂体系并深入理解了相关的催化机理，并为之后的实验制备及应用提供了理论依据。相关的研究工作发表了SCI论文27篇，已接收待发表2篇。另外培养了培养博士后1名、高水平硕士研究生4名并都已经或有意向读博深造。