ZnO Nanobelt Based Conductometric H2 and NO2 Gas Sensors

Conductometric H₂ and NO₂ gas sensors based on single-crystalline ZnO nanobelt sensitive layers have been developed. These layers were deposited using a rf magnetron sputterer. TEM and SEM characterization methods were employed to study the morphology of the nanobelts. These sensors were exposed to H₂ and NO₂ gases at operating temperatures between 225degC and 420degC. Study showed that sensors responded with highest magnitude at above 300degC. The fastest response and recovery times, with greater repeatability occurred at 385degC and 350degC for H₂ and NO₂ gases, respectively. Sensor with ZnO nanobelts has a much lower optimum operational temperature than that of conductometric sensors with other forms of ZnO crystal layers