First-principles studies of HF and HCl adsorption over graphene.

In this paper, the adsorption characteristics of HF and HCl over graphene were studied by the first-principles method. The results showed that the adsorption of HCl over graphene was a weak chemical adsorption, while HF was a weak physical adsorption. The density of states showed that HCl and graphene at - 4.3 eV are relative to the Fermi level. At the same time, there is no obvious change and hybridization between HF-graphene system near the Fermi level. Furthermore, when HCl and HF molecules adsorbed over the graphene simultaneously, two optimal adsorption structures would be chosen to investigate how HCl and HF molecules jointly affected adsorption properties. The result showed that two gas molecules adsorbed over graphene could enhance the adsorption effect and influenced electronic distribution. Graphical abstract HF and HCl over graphene belong to weak physical and chemical adsorption separately. Two gases on graphene surface can be enhanced.