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 In2O3 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 In2O3 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 In2O3 were discussed. The sensor based on In2O3 (380 °C − 30 min)-SE exhibited superior gas-sensing performance in the range of NH3 concentration of 50–500 ppm. The NH3 response characteristics exhibited little effect at different relative humidity (RH) and oxygen partial pressure conditions. In addition, the sensor exhibited good repeatability and selectivity. •In2O3 was synthesized by the salt melt method and used as the SE for the NH3 sensor.•The sensitivity of the sensor is nearly unaffected by O2 concentration and RH.•The sensor exhibits good anti-interference performance to NO and NO2.