Acetone-Assisted Oxygen Vacancy Diffusion on TiO2(110)

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• 作者：Yaobiao Xia ; Bo Zhang ; Jingyun Ye ; Qingfeng Ge ; Zhenrong Zhang
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2012
• 出版时间：October 18, 2012
• 年：2012
• 卷：3
• 期：20
• 页码：2970-2974
• 全文大小：307K
• 年卷期：v.3,no.20(October 18, 2012)
• ISSN：1948-7185

文摘

We have studied the dynamic relationship between acetone and bridge-bonded oxygen (O_b) vacancy (V_O) defect sites on the TiO₂(110)-1 脳 1 surface using scanning tunneling microscopy (STM) and density function theory (DFT) calculations. We report an adsorbate-assisted V_O diffusion mechanism. The STM images taken at 300 K show that acetone preferably adsorbs on the V_O site and is mobile. The sequential isothermal STM images directly show that the mobile acetone effectively migrates the position of V_O by a combination of two acetone diffusion channels: one is the diffusion along the O_b row and moving as an alkyl group, which heals the initial V_O; another is the diffusion from the O_b row to the five-coordinated Ti⁴⁺ row and then moving along the Ti⁴⁺ row as an acetone, which leaves a V_O behind. The calculated acetone diffusion barriers for the two channels are comparable and agree with experimental results.

Keywords:

titanium dioxide; acetone; surface defects; diffusion; chemisorption; scanning tunneling microscope; density function theory