In-situ conversion of amorphous carbon to graphene enhances the oxidation resistance of dendritic copper powder

Copper powder has excellent electrical conductivity, but is easily oxidized by air. This limits its application in printed circuits and related fields. In this paper, graphene was grown in-situ on the surface of dendritic copper powder in order to improve the powders’ oxidation resistance and maintain its high electrical conductivity. Firstly, dendritic copper powder with a diameter of about 100-200 nm was prepared by electrochemical deposition. Then, the powder was coated with an amorphous carbon film by Plasma Enhanced Chemical Vapor Deposition (PECVD) using C2H2 at 350 °C. Finally, the amorphous carbon film was transformed into graphene at 850 °C, and dendritic copper powder coated with graphene was obtained. TG-DTA and electrical resistivity measurements showed that the oxidation resistance temperature of dendritic copper powder can be increased from 213.7 °C to 283.4 °C and the resistivity can be reduced from 0.00544 Ω·cm to 0.00308 Ω·cm by in-situ growth of graphene on the surface of copper powder. The in-situ synthesis of graphene is expected to promote the wide application of copper powder in areas requiring high electrical conductivity and oxidation resistance. [Display omitted] •Amorphous carbon is deposited at low temperature and converted into graphene at high temperature.•The oxidation resistance temperature of dendritic copper powder increase 69.7 °C by in-situ growth of graphene.•The resistivity reduced from 0.00544 Ω·cm to 0.00308 Ω·cm by in-situ growth of graphene on the surface of copper powder.