NO2 Gas Sensing Using a CF/Pani Composite as Electrode

Gas sensors based on CF/PAni composite electrodes were synthesized using the polymerization chemistry. These sensors were used for detection of toxic gases like NO2. Three different deposition times were used in the synthesis of the CF/PAni composite: 30, 60 and 90 min. The morphology and the structural characteristics of the composites were analyzed by scanning electron microscopy and Raman spectroscopy, respectively. Experiment results confirmed that the NO2 gas sensor using CF/PAni composite has good response characteristics to different NO2 gas concentrations. Furthermore, the NO2 gas sensor using CF/PAni-90 composite showed the best sensitivity. This behavior was attributed to its largest content of PAni on the carbon fiber, which induced to its largest surface area. This morphology favors the adsorption of gas molecules leading to the highest current variation with the oxidation process.