The stability of TiC surfaces in the environment with various carbon chemical potential and surface defects

摘要

The low-index surfaces of TiC are studied using the first -principles method based on density functional theory. The surface energy of TiC is calculated with consideration of the surface orientation, termination and carbon chemical potential, as well as the influence of surface vacancy defects of various concentrations. It is found that the surface relaxation results in rumpling of the (001) and (110) surfaces and the contraction of the (111) surfaces. The relative stability of the low-index surfaces of TiC varies with the carbon chemical potential, surface defects and vacancy concentrations, which will have an effect on the nanoparticles morphology and catalytic performance in practical applications. The results will serve as a guidance for understanding and designing novel TiC nanocatalysts with special morphology. (C) 2016 Elsevier B.V. All rights reserved.