Study on the surface modification and mechanism of multilayer graphene by ion beam irradiation

Abstract

To improve the poor dispersion and insufficient interfacial adhesion of reinforced graphene (GN) in copper matrices, the graphene surface is irradiated with a Cu ion beam. To study the mechanism of surface modification of irradiated Cu ^+2 sample on the surface of graphene, the Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM), and transmission electron microscope (TEM) are employed. The results of Raman spectroscopy showed that the value of relative intensity ratio I _D / I _G of the characteristic peaks of unirradiated graphene was 1.2530 where it became 0.8693 after the irradiation process. It showed an 30.6% reduction in the ratio of I _D / I _G indicating that the ion beam irradiation reduces the surface defects of graphene and causes obvious modification effects. XPS results showed that the irradiated Cu deoxidizes with the epoxy, hydroxyl, or carboxyl group on the surface of the GN, resulting in Cu compounds attached to the surface of the GN. In addition, irradiation introduces stress on the graphene surface to promote the formation of a wrinkled structure to cause the surface morphology to change, as witnessed by the rougher surface morphology, as compared to the unirradiated area. The TEM results showed a recrystallization on the surface of the GN after the irradiation process. Moreover, it showed that the GN lattice was significantly qualified. Ion beam irradiation improves the quality of the surface of GN lattice, reduces the surface defects of graphene, and displays obvious modification effects.

Keywords

• irradiation
• graphene
• surface
• modifications