| Title: | Band bending of TiO(2) induced by O-xylene and acetaldehyde adsorption and its effect on the generation of active radicals |
| Author(s): | Zeng Q; Wang X; Xie X; Mahmood A; Lu G; Wang Y; Sun J; |
| Address: | "State Key Lab of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050, China; University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China. State Key Lab of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050, China. State Key Lab of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050, China. Electronic address: xxfshcn@163.com. State Key Lab of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050, China. Electronic address: jingsun@mail.sic.ac.cn" |
| DOI: | 10.1016/j.jcis.2020.03.114 |
| ISSN/ISBN: | 1095-7103 (Electronic) 0021-9797 (Linking) |
| Abstract: | "Most studies on the photodegradation of volatile organic compounds (VOCs) have focused on the synthesis of efficient photocatalysts. However, little attention has been paid to the band bending change of semiconductive photocatalysts after the adsorption of VOCs. Herein, we first disclose how the adsorption of two typical VOCs influences the band bending of P-type rutile TiO(2) and consequently changes the amount of reactive radicals. This provides a new way to understand the experimental phenomenon of heterogeneous reactions. Theoretical computations of the adsorption model and zeta potential tests both verified that o-xylene is an acceptor molecule when it adsorbs on the TiO(2) surface, and it tends to attract electrons from TiO(2). In contrast, acetaldehyde is a donor molecule. A distinct electron transfer direction between TiO(2) and adsorbed molecules (o-xylene and acetaldehyde) induces a different band bending degree. O-xylene adsorption alleviates the downward band bending of TiO(2) itself, whereas acetaldehyde adsorption strengthens the downward band bending. The probability of electrons and holes reaching the TiO(2) surface is influenced by this change, which has a considerable influence on the generation of active radicals. Consequently, o-xylene adsorption leads to more hydroxyl radical generation, and acetaldehyde adsorption results in less hydroxyl radical generation. As a result, hydroxyl radicals play the predominant role in the degradation of o-xylene, whereas the photocatalysis of acetaldehyde is dominant for superoxide radicals. In addition, the band bending of a semiconductor induced by gaseous molecule adsorption has the potential for application in gas sensors to improve sensitivity" |
| Keywords: | Acetaldehyde Active radicals Band bending O-xylene Photocatalysis Sol-gel method; |
| Notes: | "PubMed-not-MEDLINEZeng, Qinglong Wang, Xiao Xie, Xiaofeng Mahmood, Asad Lu, Guanhong Wang, Yan Sun, Jing eng 2020/04/10 J Colloid Interface Sci. 2020 Jul 15; 572:374-383. doi: 10.1016/j.jcis.2020.03.114. Epub 2020 Mar 31" |
