Understanding Carbon Nanotube Voltammetry: Distinguishing Adsorptive and Thin Layer Effects via “Single-Entity” Electrochemistry
Archana Kaliyaraj Selva Kumar, Richard G. Compton
Abstract
Cyclic voltammetry of ensembles of nanotube-modified electrodes fails to distinguish between signals from electroactive material adsorbed on the tubes from those due to a thin-layer response of analyte material occluded in the pores of the ensemble. We demonstrate that the distinction can be clearly made by combining cyclic voltammetry with single-entity measurements and provide proof of concept for the case of b-MWCNTs and the oxidation of 4-hexylresorcinol (HR), where the increased signals seen at the modified electrode are concluded to arise from thin-layer diffusion and not adsorptive effects. The physical insights are generic to porous, conductive composites.
Topics & Concepts
Cyclic voltammetryCarbon nanotubeMaterials scienceElectrodeLayer (electronics)ElectrochemistryVoltammetryAdsorptionThin filmDiffusionNanotechnologyPorosityThin layerNanotubeChemical engineeringAnalytical Chemistry (journal)ChemistryComposite materialChromatographyOrganic chemistryPhysical chemistryThermodynamicsEngineeringPhysicsElectrochemical Analysis and ApplicationsElectrochemical sensors and biosensorsConducting polymers and applications