Microjet ring electrode (MJRE): Development, modelling and experimental characterisation
Bitziou, Eleni, Rudd, Nicola C. and Unwin, Patrick R.. (2007) Microjet ring electrode (MJRE): Development, modelling and experimental characterisation. Journal of Electroanalytical Chemistry, Vol.602 (No.2). pp. 263-274. ISSN 0022-0728Full text not available from this repository.
Official URL: http://dx.doi.org/10.1016/j.jelechem.2007.01.014
A novel type of hydrodynamic ultramicroelectrode (UME) is described, which employs a ring UME coupled to a high speed perpendicular impinging microjet. Two types of ring UME have been fabricated, both based on an optical fibre, coated in a thin metal film, which is then sealed using either epoxy resin or glass. After polishing, a thin ring UME (approximate to 300-1000 nm) is obtained. When employed in the impinging microjet system, both UMEs show an increase in mass-transport-limited current with flow rate, for simple redox processes such as the reduction of Ru(NH3)(6)(3+) or methyl viologen dication in aqueous solution. However, the mass-transport rates observed are significantly lower than predicted by solving the Navier-Stokes and diffusion equations for an idealised coplanar UME. Characterisation of the UMEs with microscopy reveals imperfections on a 10 nm-1 pin length scale which impact mass-transport significantly. When these imperfections are included in the simulations, it is possible to account for the transport-limiting currents observed experimentally. A general implication of the studies in this paper is that even small perturbations in electrode structure can dramatically influence high-speed convective flow across small-scale UMEs, such that thorough geometric characterisation of UMEs employed in fast-flow systems is important. (c) 2007 Elsevier B.V. All rights reserved.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry|
|Divisions:||Faculty of Science > Chemistry|
|Journal or Publication Title:||Journal of Electroanalytical Chemistry|
|Date:||15 April 2007|
|Number of Pages:||12|
|Page Range:||pp. 263-274|
|Access rights to Published version:||Restricted or Subscription Access|
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