Enhancing the corrosion resistance of aluminum by superhydrophobic silane/graphene oxide coating

Superhydrophobic silane/graphene oxide (GO) composite coating was successfully synthesized on aluminum surface by a facile dipping and curing process. The structure and composition of the obtained composite coating was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectra and X-ray photoelectron spectroscopy. Surface characterization results suggested that the single-layer GO functionalized with silane and formed uniform coating on aluminum surface. Electrochemical impedance spectroscopy (EIS) and electrochemical noise were used to investigate the anti-corrosion behavior of the prepared superhydrophobic silane/GO coating on aluminum in 1 M NaCl solution. The EIS results indicated that the prepared silane/GO coating exhibited the largest impedance compared with the silane coating and bare aluminum substrate. Besides, the values of Rct for the prepared superhydrophobic silane (936 Ω cm2) and silane/GO coatings (1670 Ω cm2) are more than 24 and 43 times that of the bare aluminum substrate (38.5 Ω cm2), respectively. Moreover, the pitting corrosion process of aluminum in NaCl solution was strongly inhibited in the prepared superhydrophobic silane and silane/GO coatings. Therefore, this work supplies an easy and economical way to prepare outstanding anti-corrosion coatings on aluminum surface, which promises a significant potential for practical applications.