No abstract

In this study, electrochemical exfoliation method was adopted in the production of graphene oxide (GO). The electrolyte used was sodium dodecyl sulphate (SDS) aqueous solution at various concentrations from 0.001 to 1.0 M. The effect of SDS concentrations on the morphology of GO samples were characterized using field emission scanning electron microscopy (FESEM), energy dispersive X-ray, micro-Raman and UV-Vis spectroscopy. As evident by the FESEM analysis, the concentration of SDS does give effect to the GO obtained in this study. The lowest GO production is given by the lowest concentration of SDS used which is 0.001 M. However, in term of ID/IGratio, the sample prepared at 0.001 M has the lowest value (0.33) as compared to the sample prepared with highest SDS concentration of 1.0 M (ID/IG~1.12). Meanwhile, the presence of absorbance peaks in the range of 224-237 nm from UV-Vis spectra analysis were seen for the whole samples and this indicate the formation of GO.

Graphene is a remarkable material with high electron mobility, good mechanical strength and almost transparent. In this paper, we review the available methods which are chemical vapour deposition, Hummers and electrochemical exfoliation method for the production of graphene. Among the extensive studies in the application of graphene, supercapacitor has gained much attention nowadays. Therefore, we also briefly review the application of graphene as electrodes for the supercapacitor devices.

Carbon nanotubes (CNTs) were successfully synthesized using waste cooking palm oil (WCPO) as precursor by modified double-stages thermal chemical vapor deposition set-up. The total amount of 30 ml WCPO precursor was consumed during the experiment with 5.33 wt% ferrocene as catalyst. Precursor volume of 2 ml was injected continuously for different time intervals of 5, 8, 10 and 12 minutes respectively. The effect of time interval between injections on the production of CNTs were systematically studied using field emission scanning electron microscopy, micro-Raman spectroscopy and current-voltage (I-V) measurement system. It was detected that the differences in time interval of injections resulted in different quality and diameter of CNTs produced. Sample produced at 10 minutes of time interval of injection gave the smallest tubes diameter in the range of 39.45-49.01 nm and good crystallinity of 0.69 ID/IG ratio. This sample also gave the best I-V characteristic with conductivity of 6.06 x 10-1 S/cm.

This paper reviews the mass production of carbon nanotubes via chemical vapor deposition method using conventional and bio-hydrocarbon precursors. Its applications in nanocomposite material and energy storage are also briefly reviewed.