Gas sensing performance of TiO2-Al2O3 pellets

Nanoparticles of Titanium dioxide (TiO₂) in anatase phase have been synthesized through a homogeneous precipitation method using titanium butoxide (Ti(OBu)4 as precursor of Ti. The synthesis was performed by mixing (Ti(OBu)4 in ethanol at 55°C. Then, glacial acetic acid and sulfuric acid were slowly added under constant magnetic stirring until obtaining a white precipitate. Afterwards, this precipitate was centrifuged, dried, calcined, and milled in a planetary ball milling. All powders were characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). To study the gas sensing properties, pellets were manufactured from synthesized TiO₂ powders, these properties were evaluated by measurement of surface resistance change of pellets, at different temperatures and propane concentrations. Additionally, to increase the gas sensing response of pellets to propane gas, the TiO₂ powders were mixed with different proportions of alumina (Al₂O₃) powders, this mixture was carried out in order to increase the porosity of pellets, hence increasing the surface area.