| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1414545 | Carbon | 2013 | 13 Pages |
The broad application of graphene is impeded by its intrinsically insoluble property. Therefore, two types of water dispersible graphene were synthesized by the reaction of graphene oxide (GO) with sodium 4-aminoazobenzene-4′-sulfonate (SAS) and its aryl diazonium salt (ADS). The maximum dispersibilities of SAS- and ADS-functionalized graphene (SAS-G and ADS-G) in water were 1.4 and 2.9 mg mL−1, respectively. Fourier transform infrared, Raman and X-ray photoelectron spectroscopy (XPS) revealed successful surface modification of graphene using SAS and ADS. The electrical conductivity of ADS-G (1120 S m−1) was much greater than SAS-G (149 S m−1), which is attributed to two-step reduction of GO to graphene. Thermogravimetric analysis revealed that excess surface modifier was attached to the surface of the ADS-G compared to SAS-G, which corroborates the Raman and XPS analysis. The electrochemical properties of the formed SAS-G and ADS-G were investigated, and the results demonstrated that ADS-G showed better specific capacitance (210 F g−1) than SAS-G (170 F g−1). All these observations confirmed that the surface modified graphene can be used as energy storage electrode materials because of their high specific capacitance values.
