理论研究CO_(2)分子在金红石相TiO_(2)(110)面的吸附特性  

Theoretical study on the adsorption of CO_(2)molecules on the rutile TiO_(2)(110)

作　　者：曹毅 杨培龙 段嘉通 张浩 涂喆研[1] CAO Yi;YANG Peilong;DUAN Jiatong;ZHANG Hao;TU Zheyan(School of Science,Xi’an Polytechnic University,Xi’an 710048,China)

机构地区：[1]西安工程大学理学院,陕西西安710048

出　　处：《陕西理工大学学报（自然科学版）》2024年第2期71-78,共8页Journal of Shaanxi University of Technology:Natural Science Edition

基　　金：国家自然科学基金项目(21503153);国家级大学生创新创业项目(202110709059)。

摘　　要：采用PBE泛函和平面波超软赝势研究了CO_(2)分子在含氧空位金红石相TiO_(2)(110)表面的吸附特性,分析了4种吸附模型的吸附能、电子态密度、Mulliken电荷分布和差分电荷密度。结果表明:CO_(2)分子垂直于表面的吸附能最大,CO_(2)分子斜向吸附于表面的吸附能略小于垂直吸附,CO_(2)分子平行吸附于表面的吸附能较小,说明垂直于表面吸附的稳定性最好;CO_(2)分子的C原子吸附时与表面Ti原子没有明显的电子云交叠,而O原子吸附时与表面Ti原子存在明显的电子云交叠,说明金红石表面的Ti_(5c)原子更倾向与CO_(2)分子中的O原子结合;4种吸附CO_(2)的C_(2p)或O_(2p)电子均在费米能级附近形成态密度峰值,其中垂直吸附时形成的态密度峰值最为显著,进一步证实了垂直吸附的稳定性最好。研究结果为金红石相TiO_(2)的CO_(2)吸附和捕集提供了一些可靠的理论依据。The adsorption of CO_(2)molecules on the rutile TiO_(2)(110)with oxygen vacancy were studied by the PBE functional and the plane wave ultra-soft pseudopotential.The adsorption energy,the density of state,the Mulliken charge distribution and the charge density difference of four adsorption models were analyzed.The theoretical results show that the adsorption energy of CO_(2)molecule perpendicular to the surface is the largest,the adsorption energy of CO_(2)molecule tilted to the surface is slightly less than that of vertical adsorption,and the adsorption energy of CO_(2)molecule parallel to the surface is small.It is indicated that the stability of vertical adsorption is the best.When the C atom in CO_(2)molecule is adsorbed to the surface,there is no obvious electron cloud overlap between the C atom and the surface Ti atom.However,when the O atom in CO_(2)molecule is absorbed to the surface,there is an obvious electron cloud overlap between the O atom and the surface Ti atom,which indicates that the Ti_(5c)atom on the surface is inclined to bind with the O atom in CO_(2)molecule.In the four adsorption models,C_(2p)or O_(2p)electrons of CO_(2)contribute the peak of density of state near the Fermi level,and the vertical adsorption shows the most significant peak,which further confirms that vertical adsorption is the most stable.This work provides some reliable theoretical results for CO_(2)adsorption and capture on the rutile TiO_(2).

关 键 词：金红石相TiO_(2) CO_(2)表面吸附 密度泛函理论 电子态密度 差分电荷密度 

分 类 号：O647.3[理学—物理化学]