An improved strategy to synthesize graphite oxide with controllable interlayer spacing as coatings for anticorrosion application

Abstract

AbstractA facile method to synthesize nanoscale graphene oxide (GO) with controllable interlayer spacing was carried out using two‐step oxidation process and much less acid to improve the efficiency of the oxidation. The X‐ray diffraction results demonstrated that GO had been successfully prepared from graphite because of disappearance of characteristic peaks of pristine graphite at about 2θ = 26.5° along with appearance of a sharp major peak of GO at about 2θ = 9.4°. The increased basal spacing d001of as‐prepared GO could reach as high as 9.39 Å, suggesting higher degree of oxidation than that prepared by the classical Hummers' synthesis, and characterization results from Fourier transform infrared spectrometer, X‐ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy further confirmed this conclusion. The influence of GO on anti‐corrosion performance of nanocomposite coatings composited with the 2,5‐dimethoxyaniline (DMA) conductive polymer was examined via potentiodynamic polarization curve tests in 3.5 wt% NaCl aqueous solution. The results demonstrated that the incorporation of GO significantly decreased the corrosion current density (icorr= 2.62 μA/cm2) in the case of GO‐PDMA coating, reflecting excellent physical isolation of GO and its synergistic effect with PDMA against the infiltration of water and corrosive electrolyte.