In situ FT-IR investigation on the reaction mechanism of visible light photocatalytic NO oxidation with defective g-C_3N_4

作     者：Hong Wang Wenjie He Xing’an Dong Haiqiang Wang Fan Dong 

作者机构：Chongqing Key Laboratory of Catalysis and New Environmental Materials College of Environment and Resources Chongqing Technology and Business University Department of Environmental Engineering Key Laboratory of Polluted Environment Remediation and Ecological Health of Ministry of Education Zhejiang University 

出 版 物：《Science Bulletin》 (科学通报（英文版）)

年 卷 期：2018年第63卷第2期

页      面：117-125页

核心收录：

学科分类：0832[工学-食品科学与工程（可授工学、农学学位）] 081705[工学-工业催化] 08[工学] 0817[工学-化学工程与技术] 083203[工学-农产品加工及贮藏工程] 

基　　金：supported by the National Key Research and Development Plan (2016YFC02047) the National Natural Science Foundation of China (51478070, 21777011 and 21501016) the Innovative Research Team of Chongqing (CXTDG201602014) the Natural Science Foundation of Chongqing (cstc2017jcyj BX0052, cstc2016jcyj A0481) 

主　　题：g C3N4 Visible light photocatalysis Defects In situ FT IR Reaction mechanism 

摘      要：The g-C_3N_4 with different structures was prepared by heat treatment using urea(CN-U) and thiourea(CN-T) as precursors under the same conditions. The microstructure and optical properties of the photocatalyst were analyzed with advanced tools. The results showed that the CN-U has a porous structure, a high specific surface area and a wide band gap in comparison with CN-T. The in situ FT-IR technique was used to monitor the adsorption and reaction process of visible photocatalytic NO oxidation on g-C_3N_4. The corresponding reaction mechanism was proposed based on the results of reaction intermediate observation and electron paramagnetic resonance(EPR) radical scavenging. It was revealed that(1) the presence of defective sites favored the adsorption of gas molecules and electronically compensated it leading to promoted formation of the final products;(2) the high separation efficiency of photogenerated electron-hole pairs enhanced the production of radicals during the photocatalytic reaction;(3) the hydroxyl radicals(-OH) are not selective for the decomposition of pollutants, which are favorable to the complete oxidation of the reaction intermediates. The above three aspects are the main reasons for the CN-U possessing the efficient visible light photocatalytic activity. The present work could provide new insights and methods for understanding the mechanism of photocatalysis.