Facile synthesis of reduced graphene oxide/MWNTs nanocomposite supercapacitor materials tested as electrophoretically deposited films on glassy carbon electrodes

Abstract

. (2013). Facile synthesis of reduced graphene oxide/MWNTs nanocomposite supercapacitor materials tested as electrophoretically deposited films on glassy carbon electrodes. Journal of Applied Electrochemistry, 43 (9), 865-877.Facile synthesis of reduced graphene oxide/MWNTs nanocomposite supercapacitor materials tested as electrophoretically deposited films on glassy carbon electrodes AbstractThis paper reports on a facile synthesis method for reduced graphene oxide (rGO)/multi-walled carbon nanotubes (MWNTs) nanocomposites. The initial step involves the use of graphene oxide to disperse the MWNTs, with subsequent reduction of the resultant graphene oxide/MWNTs composites using l-ascorbic acid (LAA) as a mild reductant. Reduction by LAA preserves the interaction between the rGO sheets and MWNTs. The dispersion-containing rGO/MWNTs composites was characterized and electrophoretically deposited anodically onto glassy carbon electrodes to form high surface area films for capacitance testing. Pseudo capacitance peaks were observed in the rGO/MWNTs composite electrodes, resulting in superior performance with capacitance values up to 134.3 F g-1 recorded. This capacitance value is higher than those observed for LAA-reduced GO (LAA-rGO) (63.5 F g-1), electrochemically reduced GO (EC-rGO) (27.6 F g-1), or electrochemically reduced GO/MWNTs (EC-rGO/MWNTs) (98.4 F g-1)-based electrodes. AbstractThis paper reports on a facile synthesis method for reduced graphene oxide (rGO)/multi-

Oxygen-modified multiwalled carbon nanotubes: physicochemical properties and capacitor functionality

“…The temperatures of maximum thermal decomposition in air, deduced from derivative weight curve (Figure 4b), were 636, 634, 618, 614 and 612°C for HCl/HNO 3 (1:3, v/v), pristine, H 2 O 2 , HNO 3 and HCl treated MWCNTs, respectively. The decrease in thermal stability upon treatment is often associated with the attachment of oxygencontaining groups on MWCNT walls and the destruction of the MWCNTs hexatomic structure [35].…”

“…Additionally, a decrease in OD of MWCNTs, especially after HNO 3 treatment, could mean the most defective shells were removed leaving the most thermally stable inner layers. Also, the Figure 2b) associated with HCl treatment is a possible reason for them being the more thermally stable than those from harsh treatments like HNO 3 . This culminates in diverse reactivity of inner and outer layers of MWCNTs and, hence, also contributes to the slight peaks at ca.…”

“…Additionally, Likodimos et al [27] were able to vary the textural characteristics of the MWCNTs using different concentrations of HNO 3 along with hydrothermal treatment techniques. Pumera [28] treated CNTs in HNO 3 at 80°C for 24 h under reflux and reported enhanced capacitance because of a rugged surface and an increase in the porosity of double-walled carbon nanotubes and single-walled carbon nanotubes. Huang et al [29] studied the effect of concentrated nitric acid-treated MWCNTs loading on activated carbon in ECs and reported a 15% enhancement at 10 wt.%.…”

Application of GO in Energy Conversion and Storage

“…The interdigitated RGO-CNT electrodes can increase the accessibility of electrolyte ions into graphene sheets and therefore lead to a high-frequency response of the micro-supercapacitors with resistive-capacitive time constants as low as 4.8 ms. Furthermore, the GO/RGO-CNT composites have been deposited on the carbon cloth for SC application [161,162]. In these composites, GO plays an important role in facilitating the deposition of CNTs on carbon cloth, and the existence of CNTs prevents the GO restacking simultaneously.…”

Preparation and Electrochemical Capacitive Behavior of Graphene by Microwave Assisted Thermal Reduction of Graphite Oxide in Hydrazine Hydrate

“…1 In the practical application, carbon and its allotropes are the most commonly used electrode materials for EDLCs due to their high surface area to weight ratio, long cycle life, excellent electrochemical stability, high electrical conductivity and low production costs. [2][3][4][5][6] Graphene is a promising alternate electrode material for the electrical application due to its reported vast surface area, large electrical conductivity, unique electron transfer and charge carrier rates [7][8][9] among all the carbon materials. Chemical reduction using agents such as hydrazine or dimethylhydrazine, 10,11 and NaBH 4 (Ref.…”