Promoting ring-opening efficiency for suppressing toxic intermediates during photocatalytic toluene degradation via surface oxygen vacancies

作     者：Xing'an Dong Wen Cui Hong Wang Jieyuan Li Yanjuan Sun Haiqiang Wang Yuxin Zhang Hongwei Huang Fan Dong 

作者机构：Engineering Research Center for Waste Oil Recovery Technology and Equipment of Ministry of Education Chongqing Key Laboratory of Catalysis and New Environmental Materials College of Environment and Resources Chongqing Technology and Business University Chongqing 400067 China Research Center for Environmental Science & Technology Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China Chengdu 611731 China College of Architecture and Environment Sichuan University Chengdu 610065 China Department of Environmental Engineering Zhejiang University Hangzhou 310027 China State Key Laboratory of Mechanical Transmissions College of Materials Science and Engineering Chongqing University Chongqing 400044 China National Laboratory of Mineral Materials School of Materials Science and Technology China University of Geosciences Beijing 100083 China 

出 版 物：《Science Bulletin》 (科学通报（英文版）)

年 卷 期：2019年第64卷第10期

页      面：669-678页

核心收录：

学科分类：07[理学] 08[工学] 

基　　金：supported by the National Key R&D Plan(2016YFC02047) the National Natural Science Foundation of China(21822601,21777011,and 21501016) the Innovative Research Team of Chongqing(CXTDG201602014) the Key Natural Science Foundation of Chongqing(cstc2017jcyjBX0052) the Plan for ‘‘National Youth Talents” of the Organization Department of the Central Committee 

主　　题：Photocatalysis Oxygen vacancies Toluene Rate-determining step In situ DRIFTS 

摘      要：Aromatic ring-opening process is well recognized as the rate-determining step for catalytic toluene degradation. In photocatalytic toluene degradation, the toxic intermediates w让h harmful effects may be generated. To clarify the precise reaction mechanism and control the toxic intermediates generation, a closely combined in situ DRIFTS and DFT calculation is utilized to address these important issues. We construct the BiOCl w让h oxygen vacancies (OVs) and reveal the structure of OVs. The defect level caused by oxygen vacancies could promote the light adsorption and charge separation, which further boosts the activation of ring-opening species and enhances the generation process of free radicals. The reaction energy barriers of four possible ring-opening processes on defective BiOCl (OVBOC) are all declined in comparison with perfect BiOCl (BOC). The existence of oxygen vacancies could smooth the ratedetermining step so the ring-opening efficiency of photocatalytic toluene degradation is highly increased. Most importantly, the methyl species would be further oxidized and tend to open the benzene-ring at benzoic acid on BOC while the ring would be broken at the benzyl alcohol on OVBOC. These results indicate that the toluene degradation pathway is shortened via the surface OVs, which enables the production of radicals with high oxidation capability for the accelerated chain scission of the ring-opening intermediates. Finally, the efficiency of the key ring-opening process could be enormously improved and toxic intermediates are effectively restrained. The present work could provide new insights into the design of high-performance photocatalysts for efficient and safe degradation of VOCs in air.