Development of a gas sensor utilizing chemiluminescence on nanosized titanium dioxide

A gas-sensing mode based on chemiluminescence generated on the surface of nanosized materials is proposed in the present work. Seven nanosized materials were tested, and chemiluminescence was detected from six of them during the catalytic oxidation of organic vapors in air. The luminescence characteristics of ethanol and acetone vapors passing through the surface of TiO2 chosen were studied with a chemiluminescence-based detection system. The linear range of chemiluminescence intensity versus concentration of organic compounds is 40-400 mug/mL for ethanol and 20-200 mug/mL for acetone dissolved in water, respectively. X-ray powder diffraction and Raman spectrometry were used to investigate the changes in catalytic activity of TiO2 after a 60-h reaction at 380 degreesC. The results showed that the carbon deposited on the surface of TiO2, decreasing the catalytic activity, but can be removed in air by controlling the temperature at 500 degreesC for 3 h. Regenerability and no consumption of sensor substrate signify the long lifetime of the gas sensor.