Premium
Microwave Activation of Electrochemical Processes at Glassy Carbon and Boron‐Doped Diamond Electrodes
Author(s) -
Sur Ujjal Kumar,
Marken Frank,
Seager Robert,
Foord John S.,
Chatterjee Arnab,
Coles Barry A.,
Compton Richard G.
Publication year - 2005
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200403171
Subject(s) - electrode , materials science , diamond , microwave , microelectrode , microfiber , carbon fibers , glassy carbon , analytical chemistry (journal) , aqueous solution , electrochemistry , cyclic voltammetry , chemistry , composite material , composite number , physics , quantum mechanics , chromatography
Voltammetric experiments under intense microwave field conditions have been carried out at a carbon microfiber electrode, an array of carbon microfiber electrodes, and at a boron‐doped diamond electrode. For the reversible one electron redox systems Fe(CN) $\rm{ {_{6}^{3-/4-}}}$ and Ru(NH 3 ) $\rm{ {_{6}^{3+/2+}}}$ in aqueous KCl solution increased currents (up to 16 fold at a 33 μm diameter carbon microelectrode) and superheating (up to ca. 400 K at all types of electrodes) are observed. Electrodes with smaller diameter allow better signal enhancements to be achieved. From the missing effect of the supporting electrolyte concentration on the microwave enhanced currents, it can be concluded that effects observed at carbon electrodes (microwave absorbers) are due to the interaction of microwaves with the electrode material whereas for metal electrodes (microwave conductors) effects are dominated by the interaction of the microwaves with the aqueous dielectric. Short heat pulses can be applied by pulsing the microwave field and relatively fast temperature transients are observed for small electrodes. For the irreversible two electron oxidation of L ‐dopa in aqueous phosphate buffer, different types of effects are observed at glassy carbon and at boron‐doped diamond. Arrays of carbon microfibers give the most reproducible and analytically useful current signal enhancements in the presence of microwaves.