Study of electroless plating Cu by reduced graphene oxide and the effects on the microstructures and properties of RGO/Cu composites

The copper-coated reduced graphene oxide (RGO) composite powders were obtained by electroless plating method in this paper, using RGO and CuSO₄·5H₂O as the main raw materials. The mixed RGO/Cu powders were obtained by added RGO in different mass fractions (0.2%, 0.4%, 0.6%, 0.8%). RGO/Cu composite materials were prepared by pressing and sintering. Compared with the RGO/Cu composite materials without copper-coated on RGO, the microstructures and performances of RGO/Cu composite materials were tested and analyzed by X-ray diffraction, Raman spectroscopy, and field emission scanning electron microscope. The results show that, the copper-coated RGO powders disperse uniformly in the RGO/Cu composites, while the copper-uncoated RGO agglomerates seriously in the Cu matrix. The mechanical properties of composites improve with the addition of RGO, while the electrical and thermal conductivity of the RGO/Cu composites decrease with the increase of RGO content. Properties of the RGO/Cu composites prepared by copper-coated RGO are better than those of RGO/Cu composites prepared by the Cu-unplated RGO. The maximum comprehensive performances of RGO/Cu composites prepared by copper-coated RGO in RGO mass fraction of 0.4% are obtained, and the compressive yield strength and tensile strength reach 156.73 and 268.62 MPa, respectively, which increase by 109% and 14.48%, compared with the pure copper yield strength (75 MPa) and tensile strength (234.64 MPa) obtained in the same conditions, the electrical conductivity reaches 95.01% IACS and the thermal conductivity is 415.5 W·(m·K)^-1.