Sulfonated cobalt phthalocyanine-stabilized graphene: Ultrasonic exfoliation and application in anticorrosion of aluminum

Aqueous phase exfoliation (APE) has become a promising method of the graphene preparation. However, it still has some disadvantages, such as low yield and the influence of residual stabilizer on its application. Herein we report a method of the graphene preparation via APE of graphite assisted by sulfonated cobalt phthalocyanine (CoPcS) as the stabilizer. A high yield of graphene can be obtained at low concentration of CoPcS. The yield was 3.2 % in single exploitation, and the total yield reached to 7.3 % after three cycles of exfoliation. The sizes of the prepared graphene sheets were in micron level, and the percentage of few-layer graphene (<5) reached 93 %. The π-π interaction of graphene with CoPcS, as well as the repulsive interaction between negatively charged CoPcS ions, played a crucial role in stabilizing the graphene dispersion. The as-exfoliated graphene powder served directly as a filler in the epoxy coating on the surface of aluminum to improve the protection performance of the coating. A simple, cost-effective, and potential avenue has been provided to product and utilize high-quality graphene materials.