Bj. Seddon et al., DUAL-CYLINDER MICROELECTRODES .2. STEADY-STATE GENERATOR AND COLLECTOR ELECTRODE CURRENTS, Journal of the Chemical Society. Faraday transactions, 90(4), 1994, pp. 605-608
Citations number
14
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
The feedback and collection diffusion current properties of platinum d
ual-cylinder microelectrodes have been investigated using bipotentiost
atic chronoamperometry. The study focuses on the influence of the inte
relectrode spacing on the steady-state response at independently contr
olled generator and collector microcylinders. A series of such devices
were fabricated onto polyethylene terephthalate (PET) strips using a
microscope manipulation method. Micro-manipulation techniques allowed
dual-cylinder devices to be constructed using 25 mum platinum wire wit
h gap spacings from 3.5 to 188 mum and cylinder lengths 250-500 mum. R
ecycling efficiencies, expressed as an i(c)/i(g) ratio, observed with
these feedback dual-microelectrodes could be as high as 83% for closel
y spaced microcylinders. Electrochemical measurements further indicate
that a convergence of the generator and collector currents would foll
ow as the interelectrode distance diminishes below the mum scale where
the strength of the recycling flux field at the device is high enough
to minimise bulk solution exchange. The response of the new amperomet
ric device is discussed with reference to the relevant theoretical sta
tionary flux model proposed for dual-cylinder microelectrodes.