A method of manufacturing an electrical conductor includes providing a substrate layer, depositing a graphene layer on the substrate layer and selectively depositing boundary cappings on defects of the graphene layer to inhibit corrosion of the substrate layer at the defects. Optionally, the boundary cappings may include nano-sized crystals deposited only at the defects. The selectively depositing may include electrodepositing boundary cappings on exposed portions of the substrate layer at the defects. The selectively depositing may include reacting boundary capping material with exposed portions of the substrate layer at the defects to deposit the boundary cappings only at the defects.