Graphene coating on copper by electrophoretic deposition for corrosion prevention

Abstract

In this paper, we report the use of a simple and inexpensive electrophoretic deposition (EPD) technique to develop thin, uniform, and transparent graphene oxide (GO) coating on copper (Cu) substrate on application of 10 V for 1 s from an aqueous suspension containing 0.03 wt % graphene oxide. GO was partially reduced during the EPD process itself. The GO coated on Cu was completely reduced chemically by using sodium borohydride (NaBH 4 ) solution. The coatings were characterized by field emission scanning electron microscope (FESEM), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), XRD, and UV/VIS spectrophotometry. Corrosion resistance of the coatings was evaluated by electrochemical measurements under accelerated corrosion condition in 3.5 wt % NaCl solution. The GO coated on Cu and chemically reduced by NaBH 4 showed more positive corrosion potential (E corr ) (-145.4 mV) compared to GO coated on Cu (-182.2 mV) and bare Cu (-235.3 mV), and much lower corrosion current (I corr ) (7.01 μA/cm 2 ) when compared to 15.375 μA/cm 2 for bare Cu indicating that reduced GO film on copper exhibit enhanced corrosion resistance. The corrosion inhibition efficiency of chemically reduced GO coated Cu was 54.40%, and its corrosion rate was 0.08 mm/year as compared to 0.18 mm/year for bare copper.