引用本文:
【打印本页】   【HTML】   【下载PDF全文】   查看/发表评论  【EndNote】   【RefMan】   【BibTex】
←前一篇|后一篇→ 过刊浏览    高级检索
本文已被:浏览 1115次   下载 0 本文二维码信息
码上扫一扫!
分享到: 微信 更多
锐钛矿(001)表面氧化机理的第一性原理计算研究
陈宽达,史永亮,赵瑾*
作者单位E-mail
陈宽达 中国科学技术大学物理系及微尺度物质科学国家实验室合肥230026  
史永亮 中国科学技术大学物理系及微尺度物质科学国家实验室合肥230026  
赵瑾* 中国科学技术大学物理系及微尺度物质科学国家实验室合肥230026中国科学技术大学量子信息与量子科技前沿协同创新中心合肥230026美国匹兹堡大学物理系匹兹堡宾夕法尼亚州15261 zhaojin@ustc.edu.cn 
摘要:
基于第一性原理计算,研究了(1×4)重构锐钛矿(001)面的氧化过程和结构,发现了分子氧化和解离氧化两种氧化结构,并研究了氧化过程的反应势垒.通过计算表面的自由能,比较了不同的氧化结构在不同氧化率时的稳定性,并依此绘制该表面氧化结构的相图.同时也研究了晶格应力对氧化结构的影响.研究结果表明,(1×4)重构锐钛矿(001)面的氧化结构和氧化率强烈依赖于温度和压力,且晶格应力也起着重要的作用.
关键词:  表面相图,表面重构,氧化过程
DOI:10.1063/1674-0068/28/cjcp1505095
分类号:
基金项目:
Oxidation of Anatase TiO2(001) (1×4) Surface
Kuan-da Chen,Yong-liang Shi,Jin Zhao*
Abstract:
Anatase TiO2(001) surface arouses lots of research interests since it is believed to be the most reactive surface. However, recent STM measurements showed that except the defect sites, anatase TiO2(001) (1×4) reconstructed surface is inert to H2O adsorption. It was indicated that oxidation could be the reason which induces the inert surface reactivity. Therefore, it is strongly motivated to understand the oxidation structures as well as the oxidation process on this surface. In this work, based on first principles calculations, we investigated the oxidized structures and processes of TiO2 anatase (001) surface with (1×4) reconstruction. We have discovered two kinds of oxidized structures through the molecular adsorption and dissociated adsorption with different oxidation ratio. To understand the oxidation process, we studied the reaction barrier of oxidation process. We conclude the stability of different oxidized structures with different oxidation ratio by comparing the free energy of the system as a function of oxygen chemical potential. Based on that, a first-principles-based phase diagram of the low-energy oxidized surface structures is provided. The effects of the lattice stress are also studied. Results show that the oxidized structure and oxidation ratio strongly depend on the temperature and pressure. The lattice stress also plays an important role.
Key words:  Surface phase diagram, Oxidization process, Surface reconstruction