High-performance ethanol sensor of wrinkled microspheres by spray pyrolysis

Abstract Different morphologies of In2O3 were synthesized by ultrasonic spray using InCl3 and In(NO3)3 as precursors. The samples using In(NO3)3 as a precursor exhibited more excellent gas sensing performance compared with InCl3. Furthermore, different molar ratios of Sb were introduced to study the influence of Sb concentration on gas sensing performance of In2O3 microspheres. All samples have been tested by SEM, TEM, ESR and other analysis methods to help verify the chemical and structural properties of the material. A series of gas sensing tests have been carried out, 2 mol% Sb ion-doped sample showed an excellent sensing performance for 100 ppm ethanol detection, with a response of 41.3, response/recovery time of 17 s/36 s. At a high humidity atmosphere (RH = 90 %), the device exhibited higher response (60.83) and better selectivity to 100 ppm ethanol. In this study, the gas sensing and humidity sensing mechanisms of Sb ions acted on the surface of In2O3 microspheres have been discussed exhaustedly. It is a significant study of gas-sensitive materials for ethanol detection.