Sol-gel synthesis of TiO2 nano powder and study of their gas sensing performance using thick film resistors

Nano size TiO₂ powder with anatase and rutile structure was prepaired by a sol-gel method using TiCl₄ ethanol solution. The TiCl₄ acts as precursor in this reaction. The obtained product with grain size 2.80 nm. The obtained product consist of both rutile and anatase phases. These phase formed after drying of gel at 80°C.The proportion of anatase to rutile was 6:8.The high proportion of rutile phase responsible for higher gas sensitivity. The thermal stability of nano product tested using TGA-DTA technique. The nano size structure of TiO₂ was confirmed by X-Ray Diffraction Spectroscopy (XRD), Field Emission Scanning Electron Microscopy (FESEM). The gas sensitivity of material tested by preparing thick film by screen printing technique for this the thixotropic paste of material was prepared by using ethyl cellulose and butyl cellulose. The gas sensing performance of this thick film was tested for gases like ethanol, CO₂, H₂S, NH₃, CO, Cl₂, gases and observed maximum sensitivity for H₂S gas at 350 °C.