Anti-corrosion and electrically conductive inorganic conversion coatings based on aligned graphene derivatives by electrodeposition

Ultrathin conversion coatings, made from aligned graphene derivatives and ammonium zirconium carbonate(AZC), were fabricated on stainless steel by electrodeposition. Sulfonated graphene oxide (SGO) provided electronpathways and physical barriers to corrosive molecules. Electrodeposition ensured the alignment of SGO and thefacile fabrication of the coatings. AZC is an environmental-friendly crosslinking agent, water-repellent andcorrosion inhibitor. Upon dehydration reactions, AZC improved the cohesion between SGO layers and anchoredthe conversion coatings on metal substrates. When the mass ratio of SGO to AZC was 2:1, the corrosion currentdensity of the composite coatings reached 0.098 μA cm^(-2), while that of the bared stainless steel was1.04 μA cm ^(-2), given a coating thickness of only 500 nm. The electrical conductivity of SGO/AZC compositecoatings can be tailored from 3.84 × 10^(-5) to 2.28×10^(-3)S‧cm^(-1) by heat treatment and HI reduction, whichsatisfied the electrical conductivity requirement of wide applications in electronic industry, office appliances andpetroleum storage.