Amperometric determination of carbon dioxide using a gold electrode modified by the underpotential‐deposited cadmium

Abstract
An underpotential‐deposited cadmium layer formed on a gold electrode was used to amperometrically determine PCO2 in an aqueous medium. This electrode reduces nitrate anions in an aqueous solution. The reduction current produced can be related to the proton concentration. Thus, when dissolved CO2 is present in a nitrate solution it alters the proton concentration, which can then be measured amperometrically. Experimental investigation of this system and a Nafion coated gold electrode were both carried out. The effect of oxygen present in the system is also discussed.