First-Principles Investigation of Titanium Nanoparticle Oxidation
First-Principles Investigation of Titanium Nanoparticle Oxidation
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DOI：
10.1021/acs.jpcc.7b11582
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发表时间：
2018-02-08
影响因子：
3.7
通讯作者：
McKenna, Keith P.
中科院分区：
文献类型：
--
作者：
Hung, Shih-Hsuan;McKenna, Keith P.
我们进行第一性原理计算，研究钛纳米颗粒氧化的初始阶段。我们确定了最稳定的结构的181个原子的十面体纳米粒子与各种氧覆盖范围从一个单一的原子，以充分氧化的表面。发现纳米颗粒表面上的线性Q（ad）-Ti-O-ad键合构型对于低氧覆盖率是最稳定的。观察到晶格膨胀的程度逐渐增加，随着氧含量的增加，最高可达8.2%的充分氧化的表面。为了研究后续亚表面氧化的可能机制，我们计算了许多不等价的氧扩散途径的能垒。我们发现，最有利的途径涉及渗透到表面下的八面体网站在小平面的应变是最大的中心。结果提供了原子的洞察钛纳米粒子的氧化行为，并强调吸附诱导应变所发挥的重要作用。
We perform first-principles calculations to investigate the initial stages of titanium nanoparticle oxidation. We determine the most stable structure of a 181-atom decahedral nanoparticle with various Oxygen coverages ranging from a single atom to full oxidation of the surface. Linear Q(ad)-Ti-O-ad bonding configurations on the nanoparticle surface are found to be most stable for low oxygen coverage. The degree of lattice expansion is observed to gradually increase with increasing oxygen content up to 8.2% for full oxidation of the surface. To investigate likely mechanisms for subsequent subsurface oxidation, we calculate energy barriers for many inequivalent oxygen diffusion pathways. We find that the most favorable pathways involve penetration of oxygen into subsurface octahedral sites in the center of facets where the strain is largest. The results provide atomistic insight into the oxidation behavior of Ti nanoparticles and highlight the important role played by adsorption induced strain.