Semiconductor Sensor with Loaded SnO2 Nanoparticles for Early Warning of Indoor Fires

Nanosized tin dioxide material with an average particle size of 10-11 nm was prepared by a sol-gel method. The material has been tested as a gas sensitive layer of a semiconductor sensor. Platinum was introduced into the gas sensitive layer to increase the sensor response to hydrogen. It was shown that the Pt-containing sensor has high sensitivity to hydrogen: its electrical resistance changes in 9.2 times in the presence of 22 ppm H-2 in air. It was demonstrated that the sensor applicable to a wide range of H-2 measurements in air (3-935 ppm) and has a fast dynamic response. The sensor demonstrates rather good reproducibility of its signal to H-2 and withstands hydrogen overload (935 ppm) without a loss of its sensitivity to H-2 microconcentration (22 ppm). The results are prospective for applying the sensor in the detectors for early warning of indoor fires.