Direct observation of atomic step edges on the rutile TiO2(110)-(1×1) surface using atomic force microscopy
Direct observation of atomic step edges on the rutile TiO2(110)-(1×1) surface using atomic force microscopy
复制标题
使用原子力显微镜直接观察金红石 TiO2(110)-(1×1) 表面上的原子台阶边缘
DOI：
10.1039/c8cp06156d
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
and Y. Sugawara
中科院分区：
文献类型：
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作者：
H. F. Wen;M. Miyazaki;Q. Zhang;Y. Adachi;Y. J. Li; and Y. Sugawara
阐明金红石 TiO2 表面阶梯边缘的原子构型对于理解其基本反应性至关重要，而直接观察原子阶梯边缘仍然是一个挑战。 AFM 是一种强大的工具，用于以真正的原子分辨率研究表面结构，并且它提供了通过改进的技术解析阶梯边缘的真实结构的机会。在这项工作中，我们成功地对金红石TiO2(110)-(1 × 1)表面上<001>和<1−11>台阶边缘的原子构型进行了成像，并且我们沿<1−11>台阶边缘直接观察到了氧空位，表明使用AFM，一个<1−11>台阶边缘位置对应于一个氧空位。我们还利用同步 AFM/STM 测量来探索阶梯边缘的电子结构，这增强了沿 <1−11> 阶梯边缘存在氧空位的证据，并进一步证明了 <001> 阶梯边缘由 O 排终止。通过探测 O2 吸附和金簇的成核行为，探索了减少的 <1−11> 阶梯边缘的影响。研究发现沿<1−11>台阶边缘的氧空位有助于O2解离吸附，与平坦台阶上的氧空位相比没有明显差异。与之前的报道一致，减少的阶梯边缘和平台同样充当金原子/纳米颗粒的成核和生长位点。本研究提供了 TiO2(110) 表面阶梯边缘原子构型的完整表征，在研究金属氧化物的表面化学方面发挥着重要作用。
Clarifying the atomic configuration of step edges on a rutile TiO2 surface is crucial for understanding its fundamental reactivity, and the direct observation of atomic step edges is still a challenge. AFM is a powerful tool for investigating surface structures with true atomic resolution, and it provides the opportunity to resolve the real structure of step edges with improved techniques. In this work, we successfully imaged the atomic configuration of <001> and <1−11> step edges on the surface of rutile TiO2(110)-(1 × 1), and we present the direct observation of oxygen vacancies along the <1−11> step edges, indicating that one <1−11> step edge site corresponds to one oxygen vacancy using AFM. We also made use of the simultaneous AFM/STM measurements to explore the electronic structure of step edges, which enhanced the evidence of oxygen vacancies existing along the <1−11> step edges and further demonstrated that the <001> step edge was terminated by an O row. The effect of the reduced <1−11> step edges was explored by probing the O2 adsorption and the nucleation behavior of gold clusters. It was found that oxygen vacancies along the <1−11> step edges could contribute to O2 dissociative adsorption and there was no obvious difference compared with the oxygen vacancies on the flat terrace. The reduced step edge and terrace likewise acted as nucleation and growth sites for gold atoms/nanoparticles, in line with previous reports. The present study provides a complete characterization of the atomic configuration of the step edges on the TiO2(110) surface and plays an important role in investigating the surface chemistry of metal oxides.