Particle Size Effect of Silver Nanoparticles Decorated Single Walled Carbon Nanotube Electrode for Supercapacitors

Abstract

Well dispersed silver nanoparticles ͑AgNPs͒ of different sizes ͑1-13 nm͒ on single walled carbon nanotubes ͑SWCNTs͒ were synthesized by a facile room-temperature deposition-precipitation process. The morphology and microstructure of samples examined by the transmission electron microscopy showed a monodispersed silver particle decorated SWCNT of 2 wt % as determined by the Rietveld phase analysis of powder X-ray diffraction patterns. The chemical state of silver determined from the binding energies of high resolution Ag 3d peaks from X-ray photoelectron spectroscopy revealed a silver ͑Ag 0 ͒ oxidation state. Electrochemical properties were studied using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance studies. Silver decorated SWCNTs demonstrated to be effective bifunctional charge collectors and active electrode materials for a supercapacitor, exhibiting a higher specific capacitance ͑106 F g −1 ͒ compared to pristine SWCNT ͑47 F g −1 ͒. An enhancement observed with AgNP decoration is highly size-dependent and is related to the improved intertube contact resistance, electroactive surface considerations, as well as the participation of Ag in a faradaic reaction induced pseudocapacitance. Decorating the SWCNT with 1 nm AgNP doubled the energy density of the device, which on charge-discharge cycling retained 84% of the initial capacitance at the end of 8000 cycles.

Bendable solid-state supercapacitors with Au nanoparticle-embedded graphene hydrogel films

“…Compared with the GH SC (R ct  = 16 Ω and R int  = 35 Ω), the NP-GH SC has relatively lower values of R ct (3 Ω) and R int (21 Ω), owing to the embedding of the high conductivity Au NPs. In particular, the relatively lower R int of the NP-GH SC is due to the increase in the number of conducting paths by the addition of Au NPs; the additional conducting paths between an active electrode material and the current collector lower the internal resistance1920.…”

Synergistic oxidation of NADH on bimetallic CoPt nanoparticles decorated carbon nitride nanotubes

“…Both cathodic and anodic peak currents, which reflected the redox behavior of [Fe(CN) 6 ] 3−/4− , increased upon nitrogen doping. While the cathodic current of CNNTs increased slightly due to an increase in the number of defect sites and the electronic conductivity conferred by nitrogen doping [34], the cathodic current of the high loading CoPt-CNNT hybrids increased by about three-fold compared to that of the pristine CNTs. In addition to the high surface area of small CoPt NPs, CoPt NPs on CNNTs appear to facilitate electron transfer (see Fig.…”

Carbon nanotube nanocomposite-modified paper electrodes for supercapacitor applications

“…Observations indicate that the incorporation of the layer of Ag nano-ink/MWCNT composite is significant in terms of the overall performance of the supercapacitor (Wee et al 2010). In an earlier work, we evaluated electrodes based on the same type of carbon paper coated with a layer of silver nano-particulate ink, followed by a layer of MWCNTs (Korivi et al 2012).…”