Tin Oxide Nanoparticles Produced by Spark Ablation: Synthesis and Gas Sensing Properties

The synthesis parameters and results of investigation of gas sensing properties of tin oxide nanoparticles produced by spark ablation are presented. The nanoparticles have sizes below 30 nm and their specific surface area is about 40 m2/g. In order to study the gas sensing properties, a special structure comprising heater, barrier layers and contact pads was utilized. The resistance of the sensor fabricated on the basis of this structure was measured at different concentrations of hydrogen in the air (100–500 ppm) and different values of relative humidity (30–80%). At working temperature of 450°C, 100 ppm of hydrogen triggers more than 8-times decrease in the sensor resistance within the time interval of about 1 s. At the same time, the humidity variation does not have pronounced effect on the sensor resistance: less than 30% in the humidity range studied.