Fundamental aspects of antimony thin film electrodes for pH measurement.

This report concerns the investigation of the sensitivity, temperature dependence, accuracy, and the standard electrode potential EO of an antimony thin film pH electrode which was prepared with electron beam evaporation techniques. The air-formed oxide film on antimony thin film electrodes has been proved by both the cathodic reduction method and electron spectroscopy for chemical analysis (ESCA). The antimony thin film electrode responded rapidly to pH changes and its sensitivity was slightly changed depending on the buffer composition. The accuracy of this electrode was compared with that of the glass electrode. Temperature had some influence on the function of this electrode. The standard electrode potential of this electrode was discussed together with that of other forms of antimony electrodes. The structure and thickness of the surface oxide on antimony thin film electrodes was confirmed by cathodic reduction and ESCA. It was clear that the surface oxide governs the electrode reactions. Possible applications of the antimony thin film electrode are discussed stating some limitations in the use.