Cooperative roles of mechanical behavior and chemical reactions in mechanical chemical nano cutting of graphene assisted by ·OH radicals: quantum mechanics and reaction molecular dynamics simulations

Abstract In order to achieve precise and controllable cutting of graphene and to meet the high quality of cutting edges required in electronics. In this study, the tangential force, radial distribution function, dangling bonds, oxidation bonds, and density functional theory were used to investigate the mechanical behaviour, cutting damage, microscopic mechanism of chemical reactions, and feasibility of elementary reactions in mechanical chemical nano cutting graphene with different solution environments. The results show that the difference in the number of broken and interfacial bonds, dominated by the variability of chemical interactions, leads to a difference in cutting forces, and that there is a negative correlation between the number of C–C bonds and the number of C–O bonds. In the pure H2O solution environment, the unsaturated C atoms in the carbon chain undergo adsorption reactions with the solution atoms, which shows the carbon chain structures such as –C#–H2O, –C#–H, –C#–O and –C#–O. In the ·OH solution environment, the edge structure atoms obtained by mechanical chemical nano cutting of graphene are more structured, more C–O interfacial bonds are formed, and the C atoms are able to detach from the graphene in the form of C*O2. The energy barriers in the elementary reactions need to be overcome by the mechanical action of the probe, and the cooperative roles of mechanical behaviour and chemical reaction enables oxidation and smooth cutting of atoms at the slit edges of graphene.