Electrical field-induced selective adsorption behaviours on graphene/Ni heterostructured surfaces: A theoretical study

Graphene is a promising candidate as an ideal reinforcing phase for metal matrix, but the grain growth mechanism within functional graphene/metal composite is still unclear. In our work, the interface microstructures evolution process of graphene/Ni composites is proposed from a theoretical perspective using the first-principles method based on density functional theory (DFT). Specifically, the adsorption and diffusion behaviours of Ni atoms on the graphene/Ni heterostructured surfaces and the selective adsorption sites under external electrical field are comprehensively investigated. Strong interactions are verified by population analysis and charge difference density. To elucidate the influence from the external electrical field, the intensity and the direction of the external electric field are considered. Moreover, the adsorption behaviours of Ni on the boron-doped graphene are studied. It can be concluded that the preferable adsorption sites are near the edge of graphene, and the presence of graphene is favourable for fine grains, and the introduction of boron will decrease adsorption capability. It is expected that our results could provide the underlying insights to reveal the role of graphene in structural evolution and offer some theoretical guidance to rationally design graphene/metal composites.