A novel thermocouple microelectrode for applications in SECM and variable temperature electrochemistry

Abstract

This paper describes a novel method for the fabrication of a thermocouple microelectrode by melting Pt and Pt–Rh wires into a measuring junction using a hydroxygen flame. A thermocouple with a tip apex diameter of approximately 20μm can be fabricated by sharpening the two wires by electrochemical etching, followed by merging of the two etched ends into a spherical joint to act as the measuring point. The as-fabricated microelectrode can work as a kind of thermocouple to measure the local temperature of the electrode. The microelectrode can be employed to study the electrocatalytic oxidation of methanol. Most importantly, the thermocouple microelectrode can be employed as an SECM tip, for example in the measurement of the reactivity of Cu patterns with bromine on a circuit board over a variable temperature range.