SYNTHESIS OF SrTiO3 NANOPOWDER BY SOL-GEL-HYDROTHEMAL METHOD FOR GAS SENSING APPLICATION

Strontium titanate (SrTiO3) nanopowder has been synthesized through a sol-gel-hydrothermal method. The X-ray diffraction studies of SrTiO3 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 angstrom. The particle size calculated from FWHM was similar to 22 nm. SrTiO3 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 H2S 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 H2S, CO, CO2, H-2, Cl-2, LPG, C2H5OH, O-2, NH3 and NO2 as test gases. The sensitivity was found to lie below and around the ppm level for H2S gas at 150 degrees C.