摘要
采用基于密度泛函理论体系下的第一性原理平面波超软赝势方法,研究了金红石相二氧化钛[TiO(2110)]表面吸附氢气(H2)的微观机制,计算了TiO_(2)表面的吸附能、态密度、电荷布局和光学性质的变化。结果表明:单碳(C)、单钼(Mo)以及C、Mo共掺杂的金红石相TiO(2110)表面均容易吸附H2,吸附方式属于化学吸附。掺杂后,禁带中形成的杂质能级可以诱导光生电子与空穴的分离,为电子在禁带中的跃迁提供“阶梯”,改善了TiO_(2)表面的光学性质,在可见光380~780 nm范围内C、Mo共掺,单Mo掺杂和单C掺杂材料的光学性能依次降低。C、Mo共掺时,TiO_(2)表面的吸收系数和反射率峰值较未掺杂时分别提高了约5倍和6倍。本工作加深了人们对TiO_(2)表面吸附H2的微观机制的理解,利用掺杂方法改善了材料的光学性能,为TiO_(2)在H2传感器中的应用提供了理论支持。
This paper studies the microscopic mechanisms of H2 adsorption on the rutile TiO_(2)(110)surface by the firstprinciple planewave ultrasoft pseudopotential method based on density functional theory.The changes in the adsorption energy,density of states,distribution of charges,and optical properties on the TiO_(2) surface are calculated.The experimental results indicate that the rutile TiO_(2)(110)surfaces doped with C,Mo,and CMo separately can easily adsorb H2 in the way of chemical adsorption.After doping,the impurity level formed in the forbidden band can induce the separation of photogenerated electrons and holes.This provides a"step"for electron transitions in the forbidden band and improves the optical properties of the TiO_(2) surface.In the visible light range of 380-780 nm,the optical performance of CMo codoping,Mo doping,and C doping materials decreases in turn.The absorption coefficient and reflectance peak of the TiO_(2) surface doped with CMo are increased by about 5 times and 6 times,respectively,compared with those of the undoped one.This study deepens the understanding of the microscopic mechanism of H2 adsorption on the TiO_(2) surface and improves the optical properties of the material by using the doping method,which provides theoretical support for the application of TiO_(2) in hydrogen sensors.
作者
霍雅洁
罗磊
岳远霞
朱洪强
Huo Yajie;Luo Lei;Yue Yuanxia;Zhu Hongqiang(Department of Mathematics and Physics,Chongqing College of Mobile Communication,Chongqing 401520,China;College of Physics and Electronic Engineering,Chongqing Normal University,Chongqing 401331,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2022年第22期1-6,共6页
Acta Optica Sinica
基金
重庆自然科学基金(cstc2019jcyjmsxmX0560)
重庆师范大学校级基金(21XLB050)。
关键词
原子与分子物理学
氢气
密度泛函理论
二氧化钛
吸附
atomic and molecular physics
hydrogen
density functional theory
titanium dioxide
adsorption
