Low Cost Nanostructured Anatase TiO2 as a H2S Gas Sensor Synthesized by Microwave Assisted Technique

Nanosized TiO(2) powder was synthesized via microwave-assisted sol gel method, using titanium tetraisopropoxide as the precursor. The material was characterized by XRD, SEM, EDAX, TEM and UV-Visible techniques. XRD analysis showed the synthesized TiO(2) powder was 100% in anatase form. TEM reveals that as prepared TiO(2) sample consists of crystalline particles of 20-25 nm. UV-Visible study indicates the band edge observed at 390 nm and the band gap was found to be 3.2 eV of the material. Thick films of TiO(2) nanopowder were prepared by screen-printing technique. The gas sensing performances were tested for various gases. TiO(2) films showed highest response for H(2)S gas at 350 degrees C operating temperature. The quick response and fast recovery are the main features of the sensor. The effects of microstructure on the gas response, selectivity, response time and recovery time of the sensor in the presence of H(2)S gas were studied and discussed.