Liquefied petroleum gas (LPG) sensor properties of interconnected web-like structured sprayed TiO2 films

In this paper, we explore for the first time the liquefied petroleum gas (LPG) sensing properties of the interconnected web-like structured TiO2 films synthesized by a spray pyrolysis deposition method using an aqueous Ti(III) chloride solution. The TiO2 films were characterized for their structural, surface morphological, optical and electrical properties and used for LPG response measurements. The SEM analyses indicated the systematically grown web-like surface morphology, to which LPG was found to be sensitive. The deposited films were polycrystalline with pronounced orientation along the (1 0 1) plane, uniform and adherent to the glass substrate. From optical absorbance studies, the optical band gap was estimated to be 3.1 eV. Thermo-emf measurement revealed that the conductivity of the TiO2 web-like structure was of n-type. With this morphology, the maximum response of 35.8% at 698 K was recorded on exposure to 0.08 vol% of LPG.