Contrasting the electrochemical behaviors of graphene film with hexagonal boron nitride film before and after modification with stearic acid on Cu in 3.5 wt% NaCl solution

Abstract

Graphene and hexagonal boron nitride (h-BN) films were grown on the copper foil using chemical vapor deposition (CVD) method. Stearic acid was used to further repair the defects existing on both of the graphene and h-BN films. Raman spectra, Scanning probe microscope (SPM, Dimension 3100) and scanning electron microscope (SEM, Quanta 250) images confirmed the existence, thickness, and distribution of graphene and h-BN film. The morphologies of graphene and h-BN modified with stearic acid were demonstrated by SEM and SPM images. Contact angles were used to show the improvement of wettability of CVD films after modification. Electrochemical results manifested that the corrosion rate of copper foil under graphene film is 1.55 times higher than that of copper foil under h-BN film, and the corrosion rate of copper foil under graphene film is 2.87 times higher than that of copper foil under modified graphene film. SEM, SPM, laser scanning confocal microscopy (LSM, Zeiss LSM700), Raman spectra, and x-ray diffraction (XRD, D8 ADVANCE) results supported the better anti-corrosion performance of h-BN film comparing with graphene film and effective auxiliary role of stearic acid after the samples immersed in 3.5 wt% NaCl solution for 30 days. The excellent anti-corrosion ability of h-BN film was attributed to the similar laminated structure as graphene and the electrically insulating nature.