Long-term corrosion protection of Q235 steel by graphene oxide composite coating

In this work, graphene oxide (GO) and graphene oxide quantum dots (GOQDs) was successfully fabricated by the modified Hummer's method. Then, the GOQDswere introduced into Zn@epoxy composite and characterized by experimental approach. The microstructure and composition of GO and GOQDs was characterized using XRD, Raman and TEM. The corrosion resistance of the graphene@Zn@epoxy composite coating was analyzed by salt spray and potentiodynamic polarization tests. Results revealed that the incorporation of the GOQDs with a diameter of 15 nm into the Zn@epoxy matrix greatly improved the anti-corrosion property of the Zn@epoxy matrix. It was observed that GOQDs well inhibited the formation of conductive pathways compared to Zn@epoxy composite coating, and exhibited superior corrosion resistance even after 792 h salt spray test.