Synthesis and Characterization of Graphene-Oxide Reinforced Copper Matrix Composite

In this study, eletrolitical copper powder (Cu) was initially mixed with the aqueous solution of graphene oxide (GO); later, the mixture underwent mechanical stirring for 1 h, vacuum filtration, and drying for 42 h. The final concentration of GO in the composite was 0.3%wt. Through scanning electron microscopy (SEM), it was possible to observe the homogeneous dispersion of graphene sheets between copper particles, without the presence of agglomerates. In addition, X-ray diffraction (XRD) of the pure samples and after mixing revealed that there was no oxidation of the copper and the absence of peaks related to other elements, confirming the high purity of the copper used. Still, by XRD, it was possible to analyze that the graphene oxide produced was formed by stacking layers of graphene owing to the appearance of a diffraction peak referring to the plane (002), which was confirmed by Raman spectroscopy performed in GO from the appearance of the 2D bands. Fourier transform infrared spectroscopy (FTIR) allowed the identification of the vibrational spectra referring to the hydroxyl, carbonyl, and epoxy functional groups in GO, confirming that the oxidation process was effective in inserting functional groups in the basal graphical plane. Through the GO thermogravimetric analysis (TGA), it was possible to identify a significant loss of mass of approximately 30% at temperatures below 100 °C; referring to the elimination of water molecules, the most stable functional groups were eliminated at temperatures between 600 °C and 800 °C.