A LAF3-BASED OXYGEN SENSOR WITH PEROVSKITE-TYPE OXIDE ELECTRODE OPERATIVE AT ROOM-TEMPERATURE

LaF3-based oxygen sensors have been constructed by using perovskite-type oxides as new types of sensing electrode materials. The pulverized oxides are either fixed on the LaF3 surface as a thin layer by means of a holder or applied on the LaF3 surface after mixing with a binder (polystyrene or polyvinyl alcohol). The new electrodes exhibit efficient room-temperature operation, and LaCoO3 and LaMnO3 yield sensing electrodes with better sensing performance than a Pt electrode. The sensor's sensitivity as well as the response time are greatly dependent on the oxide used. The sensing mechanisms derived from the Nernst plots correspond well to the activity of the oxides for the electrochemical reduction of oxygen in an alkaline solution. © 1990.