Voltammetry at micro-mesh electrodes

Abstract

Neste trabalho investigamos a voltametria em eletrodos do tipo micromesh. Em experimento de duração suficientemente curta, os eletrodods de trabalho micromesh se comportam primeiramente como uma rede de eletrodos de microbanda, seguido pelo comportamento esperado para um arranjo de eletrodos de micro-anel, independentes de difusão, com perímetro igual ao tamanho da grade. Durante eletrólise prolongada, o eletrodo apresentou o comportamento previsto para um eletrodo parcialmente bloqueado, com arranjo cúbico. A aplicação deste eletrodo micromesh na determinação eletroquímica de dióxido de carbono em soluções eletrolíticas de DMSO é descrita. The voltammetry at three micro-mesh electrodes is explored. It is found that at sufficiently short experimental durations, the micro-mesh working electrode first behaves as an ensemble of microband electrodes, then follows the behaviour anticipated for an array of diffusion-independent micro-ring electrodes of the same perimeter as individual grid-squares within the mesh. During prolonged electrolysis, the micro-mesh electrode follows that behaviour anticipated theoretically for a cubicallypacked partially-blocked electrode. Application of the micro-mesh electrode for the electrochemical determination of carbon dioxide in DMSO electrolyte solutions is further illustrated.

Electrochemistry of immobilised redox droplets: Concepts and applications

“…Mesh electrodes have recently been shown to exhibit time-dependent features, in that at short times they act as microband electrodes followed by micro-ring behaviour, and at long times, they show voltammetric features that may be understood by comparison with a regularly-distributed (specifically cubically packed) partially blocked electrode. 72 The modified mesh, supported on one side with a transparent plastic backing, is then immersed into aqueous solutions and the potential scanned in the usual manner. It can be seen that this arrangement gives rise to quasi-steady-state oxidative currents, which generally increase with the number of individual mesh '' squares '' covered by the THPD liquid (Fig.…”

Simulation of Irreversible Electro-oxidation on a Partially Blocked Electrode

“…The material lying above the insulating part of the platform is diffusing towards the edge of the microelectrode, and thus contributes to the flux. Hence, the diffusion layers of individual electrodes overlap, and the response of the array changes from the sum of responses of the microelectrodes to the response of the planar macroelectrode [2,[6][7][8]. The arrays of microelectrodes are suitable for use in highly resistive media [9], and for the kinetic measurements using high scan rates [10][11].…”

Electrochemical measurement of the size of microband electrodes: A theoretical study

“…Fabrication methods for band electrodes have been widely discussed in the literature and include thin film deposition techniques and a lamination method [16][17][18][19]. Girault et al presented a method for the construction of band electrode based on thin film laminated materials [16], whilst the Compton group has successfully used thermal lamination method of metal foils, wires or meshes to fabricate microbands, microdiscs and a linear array of microdisc electrodes [18].…”