Titanium Based Materials for High-Temperature Gas Sensor in Harsh Environment Application

Gas selective sensors that are capable of sensing at hot-gas environment are increasingly gaining importance for the monitoring of combustion and thermal processes releasing NO, NO2 and H2 containing hot gases at temperatures exceeding 600 °C. Despite some drawbacks, TiO2 is capable of operating as a gas sensor above 500 °C. In this context, Ni-doped TiO2, Co-doped TiO2 and Rh-doped BaTiO3 have been prepared by oxalate coprecipitation route and fully characterized. Co-doping of TiO2 promotes p-type behavior exhibiting good sensing properties to NO2 while Ni-doping displays the maintenance of n-type behavior and better H2-sensing properties at 600 °C. Rh-doped BaTiO3 shows excellent NO sensing properties at 900 °C.