Modulation of photocatalytic activity of SrBi_(2)Ta_(2)O_(9)nanosheets in NO removal by tuning facets exposure  

作　　者：Nan Li Qiuhui Zhu Guimei Liu Qi Zhao Haiqin Lv Mingzhe Yuan Qingguo Meng Yingtang Zhou Jingkun Xu Chuanyi Wang 

机构地区：[1]School of Environmental Science and Engineering,Shaanxi University of Science and Technology,Xi’an 710021,China [2]Guangzhou Institute of Industrial Intelligence(GIII),Guangzhou 511400,China [3]National Engineering Research Center for Marine Aquaculture,Marine Science and Technology College,Zhejiang Ocean University,Zhoushan 316004,China [4]Flexible Electronics Innovation Institute(FEII),Jiangxi Science&Technology Normal University,Nanchang 330006,China

出　　处：《Journal of Materials Science & Technology》2022年第27期91-100,共10页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.21976116,52161145409);Shaanxi Science and Technology Program(No.2020KWZ-005);High Level Talents Introduction Project of"Pearl River Talent Plan"in Guangdong Province(No.2019CX01L308);the Support Scheme of Guangzhou for Leading Talents in Innovation and Entrepreneurship Funding(No.2016015);SAFEA of China(High-end Foreign Expert Project);Alexander-von-Humboldt Foundation of Germany(Group-Linkage Program)。

摘　　要：Photocatalysts with exposure of different crystal facets often show great differences in their photocatalytic activities due to differences in surface atomic arrangement and coordination.Thus,the actual photoreaction mechanism of a specific crystal facet in photocatalysis deserves to be explored.In this paper,as a case study,Sr Bi_(2)Ta_(2)O_(9)photocatalyst with preferential facet exposure was explored for the photocatalytic removal of NO at a ppb level.The efficiency of NO removal was remarkably improved by tuning the crystal exposure facet with high(200)facet exposure ratio.Optimized exposure of(200)crystal facet in Sr Bi_(2)Ta_(2)O_(9)(SBT)by thermal calcination at 800℃(SBT-800)leads to the highest NO removal activity of51%under a 300 W Xe lamp for 20 min;under visible light,SBT 800 achieves a 5-fold enhancement in NO removal efficiency compared to its counterpart,SBT-900.Active species capture experiments prove that the superoxide radical·O_(2)-is the main active species for the photocatalytic removal of NO,and surface selective deposition experiments conclude that(200)is the main electron-rich crystal plane,based on which the results of density functional theory(DFT)computation reveal the Bi O terminated nature of(001)crystal plane,where the models with both Bi O and Ta O terminated(001)planes were created and computated.Mechanistic study reveals that Sr Bi_(2)Ta_(2)O_(9)with a larger exposure of(200)facet provides more active reduction sites,thereby reducing more O_(2)to·O_(2)-,which further oxidizes the adsorbed NO to NO_(2)-/NO_(3)-.The present work underlines the role of facet tuning in the photoactivity modulation for NO removal photocatalytically.

关 键 词：SrBi_(2)Ta_(2)O_(9) NO removal Facet exposure Photocatalysis DFT computation 

分 类 号：O643.36[理学—物理化学] O644.1[理学—化学] X701[环境科学与工程—环境工程]