Realization of Graphene on the Surface of Electroless Ni–P Coating for Short-Term Corrosion Prevention

摘要

Graphene was first fabricated on the surface of an electroless Ni–P coating/carbon steel (Ni–P–G) to improve its corrosion resistance. Meanwhile, an electroless Ni–P coating (Ni–P) was heated (Ni–P–H) under the same condition as Ni–P–G for comparison. The morphological results showed that a wavy multilayer graphene was formed on the surface of Ni–P–G. The layer number of the graphene film was 5–10 according to the analysis of Raman spectra and observation by a high-resolution transmission electron microscope. The ID/IG ratio calculated from the Raman spectrum revealed that the graphene growing at the grain of Ni–P–H had larger grain size than that growing at the grain boundary. The electrochemical results showed a higher Rp, a lower CPEdl, and a lower corrosion rate of Ni–P–G than Q235 steel, Ni–P, and Ni–P–H, indicating a higher corrosion resistance. In addition, the surface potential map achieved by a scanning Kelvin probe presented a more positive surface potential of Ni–P–G than Ni–P with the difference being around 375–750 mV, demonstrating a lower corrosion tendency of Ni–P–G.