Synthesis of SrTiO3 Nanopowder by Sol-Gel-Hydrothemal Method for Gas Sensing Application

Strontium titanate (SrTiO 3 ) nanopowder has been synthesized through a sol-gel-hydrothermal method. The X-ray diffraction studies of SrTiO 3 nanopowder have shown that the as-prepared powder was single phase, crystalline, and has a cubic perovskite structure (ABO 3 ) with a lattice constant a = 3.903 Å. The particle size calculated from FWHM was ∼22 nm. SrTiO 3 nanopowder was examined using thermo gravimetric analysis; differential thermal analysis and UV-visible absorption spectroscopy. The transmission electron microscopic investigations have shown that the particle size of the as-prepared powder has a mean size of 34 nm. Then highly sensitive and selective sensors to H 2 S based on glass substrate were fabricated successfully by screen-printing technique. Sensitivity, selectivity, response time, and recovery time of the sensors were systematically investigated as a function of operating temperature, using H 2 S, CO, CO 2 , H 2 , Cl 2 , LPG, C 2 H 5 OH, O 2 , NH 3 and NO 2 as test gases. The sensitivity was found to lie below and around the ppm level for H 2 S gas at 150 °C.