基于TiO2@Ru-AgBrI弱可见光驱动光催化剂的构建及其降解室内VOCs的研究

The pullution from indoor VOCs contaminants such as formaldehyde, benzene series, and halohydrocarbon, have become the stealth assassin for human health. This project aims to fabricate core-shell structured composite photocatalyst Au/TiO2@Ru-AgBrI to suit the demand of indoor weak visible light intensity. We plan to improve the response of photocatalyst to weak visible light by the means of tabular grain shape designing, low electron trap doping, semiconductor compositing, and noble metal loading. On the basis various characterization techniques, we should explore the formation machnism of low electron trap as well as the machanism of its positive effect on the transfer of photogenerated carriers, aimed to point out the principle of selecting shallow electronic trap doping agent and ascertain the optimal doping position and doping amount. Another aim of this project is to investigate the synergetic effect of T-grain AgBrI and Au nanopartile SPR on the enhancement of visible light absorption, as well as the effect of T-grain shape, shallow electronic trap doping, and TiO2 cladding on improving the light quantum efficiency of photocatalyst. Moreover, this project also focuses on exploring the active species, intermediates, final products, as well as the reaction kinetics, to clarify the mechanism of VOCs degradation under weak visible light irradiation. We believe that these stuies is beneficial to the structure design and theoretcal research of weak visible light driven photocatalyst.

室内甲醛、苯系物、卤代烃等VOCs污染已成为人类健康的隐形杀手。本项目针对室内可见光强度低的特点，构建了核壳结构光催化剂Au/TiO2@Ru-AgBrI，旨在通过T颗粒形态设计、浅电子陷阱掺杂、半导体复合及贵金属负载技术，提高催化剂对弱可见光的响应，实现VOCs的高效降解。藉助各种表征手段，探索AgBrI微晶中浅电子陷阱的形成过程及其促进光生载流子传输的内在机制，指明浅电子陷阱掺杂剂的选择原则及最优化的掺杂位置和掺杂量；阐明 T颗粒AgBrI和Au纳米粒子等离子共振在拓展催化剂可见光吸收上的互补和协同机制，明确催化剂的T颗粒形态、浅电子陷阱掺杂及核壳复合结构提高光量子效率进而提高光催化活性的机理。探测参与光催化降解反应的活性物种、中间体和最终产物的结构及反应动力学，阐明弱可见光下降解VOCs的机理和反应历程，为新型弱可见驱动光催化剂的结构设计和理论研究提供借鉴。

本项目对卤化银及其复合等离子共振光催化体系进行了较为系统的研究，在催化剂的结构设计上，将双注沉积技术应用于卤化银的合成，实现了对卤化银晶面和形貌的调控，制备了一系列AgCl@Ag、AgBr@Ag和AgBrI@Ag等离子共振光催化剂。应用梯度升温和动力学控制水解工艺实现了TiO2壳层的包覆，制备了核壳结构等离子共振复合光催化剂AgCl@Ag@ TiO2和AgBr@Ag@TiO2；在理论研究上，完善和深化了卤化银光催化剂通过等离子共振实现可见光响应的机制，探索了卤化银和等离子共振协同提高可见光吸收的原理，阐明了光生载流子的产生以及在复合结构光催化体系中的传输、分离途径及其提高光催化活性的机理；在应用研究上，将所合成的一系列AgX@Ag和AgX@Ag@Ag@TiO2光催化剂应用于污染物降解，探索了催化剂结构与光催化效率之间的构效关系，厘清了该体系催化材料降解环境污染物的活性物种、降解机理和途径。此外，还制备了磁载卤化银/银和卤化银/银薄膜，考察了其在污染物降解中的重复应用性能。以上研究对光催化材料的结构设计、理论和应用研究均具有一定的参考和借鉴意义。. 通过以上研究工作，在Applied Catalysis B: Environmental、Journal of Materials Chem. A和Journal of Physical Chemistry C等SCI期刊发表SCI论文23篇，申请中国专利16项（已授权专利5项），参加国内外学术会议12人次（发表会议论文18篇），培养研究生8人。