Highly selective ethanol In2O3-based gas sensor

The sensitive composite material was prepared by loading Pt and La₂O₃ into ultrafine In₂O₃ matric material (8 nm) synthesized by microemulsion method. A highly selective ethanol gas sensor was developed based on hot-wire type gas sensor, which was sintered in a bead (0.8 mm in diameter) to cover a platinum wire coil (0.4 mm in diameter). The gas sensor was operated by a bridge electric circuit. The influences of La₂O₃ and Pt additives on C₂H₅OH sensing properties of In₂O₃-based gas sensor were discussed. The addition of La₂O₃ resulted in a prominent selectivity for C₂H₅OH, and the addition of Pt improved the response rate to C₂H₅OH without affecting the sensitivity. The temperature and humidity characteristics of the sensor output were also investigated. The selective sensor had low power consumption, significantly minor humidity and temperature dependence, high selectivity and prominent long-term stability.