Surface stability and electronic structure of CuNi alloy (111) as a potential catalyst for graphene growth-a density-functional theory study Erik Bhekti Yutomo, Fatimah Arofiati Noor, Toto Winata
Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung 40131, INDONESIA
Abstract
Controlling the number of graphene layers during its growth process is essential in realizing its practical application as a transparent conductive electrode. Based on the experimental results, growth with CuNi alloy catalysts can effectively control the number of graphene layers. However, research at the experimental level has not been supported by research at the theoretical level. Therefore, we will study the growth of graphene on a CuNi alloy catalyst using the density functional theory (DFT) method. However, in this paper, we only focus on studying the stability of the surface system of CuNi using the DFT method as a preliminary study. Based on geometry optimization, CuNi (111) has a wrinkled surface in the slab model due to the anisotropy shift of the atoms in the first layer. Furthermore, CuNi (111) has a surface energy of J/m^2 , which is between the surface energies of its components. This condition indicates that CuNi (111) has excellent stability. When forming CuNi alloy, electrons in the Cu 4s and Ni 3d orbitals have an enormous contribution in forming the metallic bonds indicated by a significant shift of the band center energy and considerable change of the number of states at the Fermi level. Our results show that the CuNi surface system can potentially be a catalyst for graphene growth in future studies.
Keywords: Band center energy, catalyst, CuNi alloy, surface energy.
