Corrosion protection of zinc by a silane conversion coating modified with graphene oxide

Abstract

Graphene possesses an adverse side effect that can aggravate metal corrosion, which impedes its applications in metal protection. This work aims to demonstrate a strategy to effectively inhibit the corrosion activity of graphene and, thus, apply graphene protection to a metal. A γ‐(2,3‐glycidoxypropyl)propyltrimethoxysilane/reduced graphene oxide (GPTMS/rGO) composite coating was prepared on a Zn surface by immersion in a GPTMS‐modified graphene oxide (GO) solution. The formation mechanism of the coating was investigated by means of scanning electron microscopy (SEM), Raman spectroscopy, Fourier transform infrared absorption (FTIR) spectroscopy, and X‐ray photoelectron spectroscopy (XPS). Afterward, the corrosion resistance of the coating was studied by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). The results show that a dense layer of the GPTMS/rGO coating covers the Zn surface during the immersion process with the GO reduction reaction. The thickness of the GPTMS/rGO composite coating is approximately 20 μm, which is much thicker than that of a GPTMS coating. Furthermore, the formed coating shows good corrosion resistance with an icorr value of 0.029 μA/cm2, and the protection efficiency of the coating reaches 99.94%. After a 12‐day immersion in a 0.6‐M NaCl solution, the coating maintains its high corrosion resistance.