Sono-electroplting of Copper-Graphene nano-composite thin films for electrofriction applications

Abstract

Graphene has been used as a reinforcement material for improving the strength of metal matrix composite due to its outstanding mechanical properties. In the present paper, the copper-graphene nanocomposite films were synthesized onto the copper substrate by a simple and cost-effective electrodeposition process. The electrolyte contains CuSO4 and H2SO4 with different concentrations of graphene (0.1, 0.3 and 0.5 g/L). The electrodeposition process was carried out at pH of 1 and at a temperature of 15-17 °C. Ultrasonication was used during electrodeposition for uniform dispersion of graphene with the copper matrix. The graphene sheets were synthesized by electrochemical exfoliation technique as nitric acid electrolyte. (001) and (002) planes of graphene sheets have been observed from X-ray diffraction. The aromatic ring of carbon C=C bond stretching vibration at 1580 cm-1 and oxygen functional groups have been observed from Fourier transform infrared spectroscopy spectra. The partial transparency and Few-layers (10-12) of graphene sheets have been observed by transmission electron microscope and High-resolution Transmission electron microscope. The SAED pattern shows the crystallographic and hexagonal structure of graphene sheets. The presences of Graphene in composite films were observed from elemental mapping analysis. There is a significant improvement of in the electrical conductivity of the films. The analysis of the wear properties of the films implies that the wear resistances has been increased with addition as well as increase of graphene content the films. The co-efficient of friction has also been decreased. However the study needs a critical assessment before drawing a definite conclusion.