Electrodeposited reduced-graphene oxide/cobalt oxide electrodes for charge storage applications

• Published in: Applied surface science 2016-09, Vol.382, p.34-40
• Main Authors: García-Gómez, A., Eugénio, S., Duarte, R.G., Silva, T.M., Carmezim, M.J., Montemor, M.F.
• Format: Article
• Language: English
• Subjects: Charge; Charge preparation; Charge storage electrodes; Cobalt oxide; Cobalt oxides; Electrodeposition; Electrodes; Heat treatment; Oxides; Reduced-graphene oxide; Scanning electron microscopy; X-ray photoelectron spectroscopy
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2016.04.113

[Display omitted] •Electrochemically reduced graphene/CoOx composites were successfully produced by electrodeposition.•The composite material presents a specific capacitance of about 430Fg−1.•After heat treatment, the capacitance retention of the composite was 76% after 3500 cycles. In the present work, electrochemically reduced-graphene oxide/cobalt oxide composites for charge storage electrodes were prepared by a one-step pulsed electrodeposition route on stainless steel current collectors and after that submitted to a thermal treatment at 200°C. A detailed physico-chemical characterization was performed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and Raman spectroscopy. The electrochemical response of the composite electrodes was studied by cyclic voltammetry and charge-discharge curves and related to the morphological and phase composition changes induced by the thermal treatment. The results revealed that the composites were promising materials for charge storage electrodes for application in redox supercapacitors, attaining specific capacitances around 430Fg−1 at 1Ag−1 and presenting long-term cycling stability.