高效光热协同三元复合催化材料的构建及其降解VOCs研究

Volatile organic compounds (VOCs), as the main source of pollutants in the atmosphere, not only damage to the ecological environment, but also cause serious harm to human health. Therefore, it is urgent to develop new materials, new principles and new technologies of high efficiency VOCs purification. This project focus on solving the problems existing in the photocatalytic abatement of recalcitrant VOCs. Therefore, we develop a novel photo-thermal synergistic composite system, which combines the photocatalytic materials and the thermocatalytic materials through the design of the core-shell-loading structure. Finally, MnO2@TiO2/g-C3N4 ternary composites materials are prepared by loading MnO2@TiO2 core-shell structure on the porous graphite-like carbon nitride (g-C3N4). The study reveals the laws of how to regulate of the structure and control of the stability of the three element interface by the structure and composition of the composite materials. The study also reveals how to affect on band structure, spectral absorption features (ultraviolet, visible light and infrared light), photoelectric and chemical properties, light and heat energy transfer and conversion characteristics by its structure and composition. The study finally reveals the essence of how the catalytic activity enhanced by core-shell coupling function, heterogeneous junction structure matching function and photothermal synergy. The implementation of this project provides a certain experimental and theoretical basis for the efficient abatement of recalcitrant VOCs.

挥发性有机物(VOCs)是大气中的主要污染物来源，不仅对生态环境造成污染，也对人类健康造成严重威胁。因此迫切需要开发高效净化VOCs的新材料、新原理和新技术。本项目针对传统光催化技术处理难降解VOCs的局限性，通过对催化材料进行核壳负载型结构设计，将光催化材料与热催化材料相结合，形成光热协同催化复合体系，最终形成核壳结构MnO2@TiO2负载于多孔类石墨相氮化碳（g-C3N4）上的MnO2@TiO2/g-C3N4三元异质结结构复合催化材料。研究并揭示复合催化材料的结构调控规律及其对三元界面结合稳固性的控制规律；揭示其结构组成对能带结构、光谱吸收特性（紫外光、可见光、红外光）、光电化学特性、光热能量传递和转换特性的控制规律；揭示核壳耦合作用、负载型异质结结构匹配作用和光热协同作用增强催化活性的本质。本项目的实施为高效去除难降解VOCs提供一定的实验和理论依据。

挥发性有机物(VOCs)是大气中的主要污染物来源，不仅对生态环境造成污染，也对人类健康造成严重威胁。本研究通过原位还原无定形态TiO2@MnO2@C前驱体，设计合成了单分散核-双壳结构C@MnOx@TiO2（简称CMT）复合材料。由于独特的核壳结构，CMT复合材料能够实现全光高效光热转化以及甲苯的快速吸附/富集，诱发光催化和全光驱动热催化的光热协同效应，提高了光热催化降解甲苯的活性。与其他CMT复合材料相比，CMT-3 (Mn/Ti=0.4）复合物表现出更好的光热催化活性，其CO2产率为102.5 μmol.g-1.min-1，是P25的21.4倍。由于其优化的外层TiO2壳层厚度以及表面氧物种（Oads、Olatt和Owat）和Mn物种（Mn2+/Mn3+/Mn4+）的最佳分配比，促进了氧化还原循环过程中氧活性物种的活化和迁移。本研究揭示了CMT复合催化材料的结构调控规律；揭示其结构组成对能带结构、光谱吸收特性（紫外光、可见光、红外光）、光电化学特性、光热能量传递和转换特性的控制规律。揭示CMT核壳耦合作用、负载型异质结结构匹配作用和光热协同作用增强光热催化活性的本质。本研究通过构建多功能核壳集成结构，为高效光热催化氧化VOCs提供了新思路。