In2O3 sensing electrode prepared by salt melt method for impedancemetric-type NH3 sensor

Salt melt synthesis is a kind of inorganic material synthesis method developed in modern times, which has certain potential advantages and development prospects. The sensing electrode (SE) material In 2 O 3 was synthesized by the salt melt method. The composition and morphology of the synthesized products under different conditions were studied in detail by combining XRD , SEM and TEM characterization. The results show that the salt melt method can facilely synthesize high-purity In 2 O 3 powder at a lower temperature, and its morphology changes regularly with the change of reaction conditions. The effects of synthesis times and temperatures on the gas-sensing performance of In 2 O 3 were discussed. The sensor based on In 2 O 3 (380 °C − 30 min)-SE exhibited superior gas-sensing performance in the range of NH 3 concentration of 50–500 ppm. The NH 3 response characteristics exhibited little effect at different relative humidity (RH) and oxygen partial pressure conditions. In addition, the sensor exhibited good repeatability and selectivity .