Simultaneous joule heating and potential cycling of cylindrical microelectrodes

An improved electrode design enabled to perform electroanalytical experiments in which a platinum wire electrode inside an aqueous electrolyte solution was continuously joule heated during dc polarization. The proposed symmetrical electrode arrangement allowed measurement of low magnitude electrochemical signals even when a high magnitude audio frequency current was used for heating. The new arrangement could open a way to amperometric sensing of sluggish reacting species without changing bulk solution temperature. The electrochemical behaviour of a platinum wire surface exposed to these conditions was considered. The heating effects are demonstrated by cyclic voltammograms of hexacyanoferrate(II)/(III) and by cathodic stripping of dissolved oxygen at the hot platinum surface.