A study on corrosion behavior of graphene oxide coating produced on stainless steel by electrophoretic deposition

The purpose of this study is to investigate the effect of thickness of adhesive graphene oxide (GO) layers electrophoretically deposited on 316 stainless steel substrate on corrosion resistance. Initially, GO was synthesized from graphite using the modified Hummer method. In order to improve the adhesion of GO coatings, substrates were subjected to electropolishing and anodizing procedures. The GO was deposited from acidic (GO/water) and alkaline (GO/water/PBS buffer) solutions. To obtain a range of coating thicknesses, the GO layers were deposited using various voltages and deposition times. The produced coatings were characterized using scanning electron microscopy, X-ray diffraction, Fourier Transform Infrared, Raman spectroscopy, thermal analysis and electrochemical tests. Based on the obtained results, a partial reduction of GO during electrophoretic process and drying steps was confirmed. Compared with electropolished surface, anodizing treatment of substrate induced a better barrier property. A higher reduction of oxygen group in GO was detected by the presence of K+ ions released from PBS buffer into the suspension. It was also found that the thin GO layers obtained from alkaline solution containing PBS buffer could improve the barrier property, while, an increase in GO layers degraded it.