Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7716759 | International Journal of Hydrogen Energy | 2014 | 8 Pages |
Abstract
The high capacitance and cyclic stability of graphene nanosheets decorated with Co3O4 nanoparticles as a material for supercapacitor electrodes are reported here. Hydrothermal method is adopted to deposit cobalt oxides on the reduced graphene oxide (RGO) sheets in a mixture of water and dimethylformamide (DMF) as the solvent with different volume ratios. The water volume ratio presents a crucial factor in the nucleation and growth process. In addition, it affects dispersion, particle size and the amount of nucleated cobalt oxide particle on the graphene sheets. By decreasing the water volume, the nucleation and growth occur mainly on graphene rather than in solution. According to the obtained results from transmission electron microscopy, scanning electron microscopy and thermogravimetric analysis, a model for growth of nanoparticles on graphene sheets is proposed. Based on the obtained results, the presented model can also be used for the synthesis of other graphene-metal (oxide) composites. Electrochemical measurements indicate that water volume ratio in the mixture solvent influences on capacitance of the RGO/Co3O4 composite electrodes. The highest obtained specific capacitance is 440.4Â FÂ gâ1 with 50% volume ratio of water at current density of 5Â AÂ gâ1.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Effat Jokar, Azam Iraji zad, Saeed Shahrokhian,