TiO2 Nanorods Based Highly Sensitive Liquefied Petroleum Gas Sensor

TiO2 thick film sensors were fabricated from TiO2 nanorods prepared by a hydrothermal method and their gas-sensing properties were investigated. The morphologies, crystal structure and optical properties of the films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and UV -visible spectroscopy. It is found that the well-proportioned TiO2 nanorods have a length of 150-200 nm and an average diameter of 10-15 nm. The TiO2 thick film sensors were tested for various gases such as CO2, LPG, CO, ethanol, NH3 and H2S etc. by varying operating temperature. The results indicate that the TiO2 nanorods thick films showed much better sensitivity to LPG (100 ppm) at 250 degrees C. The sensor also had a high selectivity and short response time to low concentrations of LPG at 250 degrees C. These characteristics make the sensor to be a promising candidate for practical materials detecting low concentrations of LPG gas against all other tested gases.