Effect of Reaction Time on the rGO-CoS Composite Structural Properties

In this research, the rGO-CoS composites were successfully synthesized from GO and the Cobalt and Sulfur precursors via solvothermal reaction. The GO material was obtained by Hummer method reaction synthesis. In term of rGO synthesis, reaction time is one of important factors that determine the reduction process and the resulting material properties. Therefore, we studied the influence of reaction time to the chemical properties of the obtained composites by varying i.e 12, 24, 36 and 48 hours of reaction time. The characterizations were carried out using Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), and Fourier Transform Infra-Red (FTIR). Morphological observation of rGo-CoS shows that rGO-CoS are has many thin layers, rougher, and wider surface. From the XRD result, GO shows shift of peak diffractogram to 2θ 9.56 ° with interplanar space 9.24 Á and rGO-CoS 36 shows several peaks at 2θ 30.84, 35.47, 47.54, 54.94°. The GO spectrum pattern shows specific functional group, OH groups (hydroxyl), carboxyl stretching vibration C=O (-COOH), C=C of unoxidized graphite consisting aromatic rings, and epoxy group vibration C-O(-C), while rGO and rGO-CoS shows decrease in intensity of these bands. It concluded that the rGO-CoS 36 (hours) is considered as the most optimum reduction reaction time. (paper)