摘要
运用第一性原理计算了氟(F)掺杂锐钛矿二氧化钛(101)(F-TiO2(101))表面水的吸附及其光氧化动力学。结果表明:光激发的空穴在F-TiO2(101)表面的电子结构中引入了缺陷态,主要分布在表面吸附的羟基和表面二配位氧原子(O2c)上;而且当水以双氢键吸附在F-TiO2(101)表面上时,电子结构中进一步产生了电子和空穴分别占据的2个缺陷态。在此基础上,系统地研究了空穴存在条件下,F-TiO2(101)表面水氧化的3种反应路径,并得到了2种最可能发生的路径:(1)水直接将氢转移到O2c原子上,同时剩余羟基转移到表面五配位钛原子(Ti5c)上;(2)水分子扩散到Ti5c原子上,然后将氢转移到O2c原子上。低反应能和适中的势垒表明,2种反应路径在可见光照射条件下均可快速地发生。
The surface water adsorption and photocatalytic oxidation kinetics of fluorine doped anatase titanium dioxide(101)(F-TiO2(101))were studied by first principles calculation.The results show that the photoexcited holes introduce defect states into the electron structure of F-TiO2(101)surface,mainly distributing on the surface adsorbed hydroxyl group and surface discoordinated oxygen atom(O2c).Furthermore,when water is adsorbed on F-TiO2(101)surface by double hydrogen bonds,two defect states occupied by electrons and holes are further generated in the electronic structure.On this basis,three reaction paths of surface water oxidation of F-TiO2(101)are systematically studied in the presence of holes,and two most likely paths are obtained:(1)water directly transfers hydrogen to O2c,while the remaining hydroxyl group is transferred to surface Pentacoordinate titanium atom(Ti5c);(2)water molecules spread to Ti5c and then transfer hydrogen to O2c.Low reaction energy and moderate barrier indicate that both reaction paths can occur rapidly under visible light irradiation.
作者
郎秀峰
崔少鑫
朱岩
梁艳红
LANG Xiu feng;CUI Shao xin;ZHU yan;LIANG Yan hong(Material Simulation and Computing Laboratory,Department of Physics,Hebei Normal University of Science&Technology,Qinghuangdao Hebei,066004;Institute of Functional Crystals,Tianjin University of technology,China)
出处
《河北科技师范学院学报》
CAS
2020年第2期44-50,73,共8页
Journal of Hebei Normal University of Science & Technology
基金
河北省自然科学优秀青年基金项目(项目编号:B2017407009)
河北科技师范学院博士启动基金资助项目(项目编号:2019YB017)
河北科技师范学院海洋科学研究专项(项目编号:2018HY023)。
关键词
TIO2
F掺杂
空穴
水分解
Titanium dioxide
fluorine doping
hole
water decomposition
