Saltwater corrosion-resistant composite coating

A saltwater corrosion resistant composite coating, comprising:

• chitosan;
• reduced graphene oxide (rGO) having a nanosheet morphology in which a plurality of wrinkled nanosheets are turbostratically stacked on top of each other;
• a conductive polymer uniformly deposited on a surface of the nanosheet of the rGO;
• and
• a cured epoxy,
• wherein the rGO and the chitosan are dispersed in particles of the conductive polymer to form a 3D network, the 3D network comprising 85-95 wt. % of the conductive polymer, 0.5-5 wt. % of the rGO, and 1-10 wt. % of the chitosan, based on a total weight of the conductive polymer, the rGO, and the chitosan,
• at least a portion of the chitosan is covalently bound to the rGO,
• at least a portion of the conductive polymer is covalently bound to the chitosan,
• the 3D network is dispersed in the cured epoxy, and
• the saltwater corrosion resistant composite coating comprises 1-10 wt. % of the conductive polymer, the rGO, and the chitosan in total, and 90-99 wt. % of the cured epoxy, based on a total weight of the conductive polymer, the rGO, the chitosan, and the cured epoxy.