Sensoy Mehmet Gokhan, Toffoli Daniele, Ustunel Hande
Department of Physics, Middle East Technical University, Dumlupinar Blv 1, 06800, Ankara, Turkey.
J Phys Condens Matter. 2017 Mar 29;29(12):125002. doi: 10.1088/1361-648X/aa57e3. Epub 2017 Jan 9.
Transition metal carbides have been extensively used in diverse applications over the past decade. Their versatility is in part thanks to their unique bonding, which displays a mixture of ionic, metallic and covalent character. While the bulk structure of zincblende (ZB) PtC has been investigated several times, a detailed understanding of the electronic and structural properties of its low-index surfaces is lacking. In this work, we present an ab initio investigation of the properties of five crystallographic ZB PtC surfaces (Pt/C-terminated PtC(1 0 0), PtC(1 1 0) and Pt/C-terminated PtC(1 1 1)). Upon geometry optimization, both polar and nonpolar surfaces undergo a mild interlayer relaxation, without extensive reconstructions. Calculated vacancy formation energies indicate facile C removal on the (1 1 1) surface while Pt-vacancy formation is endothermic. Finally, atomic O adsorption energies on all surfaces reveal a high affinity of the C-terminated surfaces towards this species.
在过去十年中，过渡金属碳化物已被广泛应用于各种领域。它们的多功能性部分归功于其独特的键合方式，这种键合方式表现出离子、金属和共价特性的混合。虽然闪锌矿（ZB）结构的PtC的体相结构已被多次研究，但对其低指数表面的电子和结构性质仍缺乏详细了解。在这项工作中，我们对五个晶体学ZB PtC表面（Pt/C端接的PtC(1 0 0)、PtC(1 1 0)和Pt/C端接的PtC(1 1 1)）的性质进行了从头算研究。经过几何优化后，极性和非极性表面都经历了轻微的层间弛豫，没有广泛的重构。计算得到的空位形成能表明，在(1 1 1)表面上C的去除很容易，而Pt空位的形成是吸热的。最后，所有表面上的原子O吸附能表明，C端接的表面对该物种具有很高的亲和力。
