Synthesis of graphene electrochemical exfoliation in different electrolytes for direct electrodeposition of a Cu/graphene composite coating.

Directly dispersing graphene into an electrolyte still remains a crucial difficulty in electrodepositing a graphene enhanced composite coating onto electrical contact materials. Herein, graphene was synthesized electrochemical exfoliation in an ,-dimethylformamide (DMF)/HO solution containing (NH)SO. The electrochemically exfoliated graphene nanosheets (GNs) were directly dispersed by sonication. In comparison with graphene synthesized from aqueous solution, the GNs electrochemically exfoliated in the DMF/HO-(NH)SO solution exhibit a lower degree of oxidation. Cu/graphene composite coatings were subsequently electrodeposited onto Cu foils by adding Cu into the as-fabricated graphene solution. The surface nanostructure of the Cu/graphene composite coatings was transformed from loose pine needles to a uniform and compact structure with an increase in the concentration of Cu, which indicated that the controllable synthesis of Cu/graphene composite coatings with different performances could be achieved in graphene dispersions after adding Cu. In order to synthesize graphene electrochemical exfoliation and directly electrodeposit a Cu/graphene composite coating without adding CuSO or any other additive, an attempt was made to directly electrodeposit a Cu/graphene composite coating in CuSO/DMF/HO solution after electrochemical exfoliation.