Electrochimica Acta, Vol.41, No.2, 337-344, 1996
An Amperometric Aqueous-Ethanol Sensor-Based on the Electrocatalytic Oxidation at a Cobalt-Nickel Oxide Electrode
An electrodeposited mixed oxide film of Co-Ni has been applied as a sensor for the amperometric determination of aqueous ethanol samples. The electrode has a linear response over a 1.5-7.9 mM ethanol concentration range with a detection limit of 32 mu M ethanol. Deposition conditions for maximum catalytic efficiency, electrode lifetime and optimum analytical analysis potential are discussed. SEM, EDAX and electrochemical kinetic studies indicate that the active catalytic species in the electrode film is a 2:1 Co-Ni oxide species and suggest a partial mechanism of the ethanol oxidation reaction. The feasibility of this modified electrode for the determination of atmospheric ethanol is also examined. All other organic alcohols tested were interferents. Conditions affecting the stability of the sensor are discussed.
Keywords:SINGLE-CRYSTAL PLATINUM;ELECTROCHEMICAL CHARACTERIZATION;ORGANIC-COMPOUNDS;ALKALINE-SOLUTION;ENZYME ELECTRODE;METHANOL;EVOLUTION;ELECTROOXIDATION;ALCOHOLS