A Room Temperature Gas Sensor Based on Sulfonated SWCNTs for the Detection of NO and NO₂

The electrical response of sulfonated single-walled carbon nanotubes (SWCNTs) to NO and NO₂, for gas sensing applications, at room temperature, is reported in this work. A specific configuration based on SWCNT deposition between double pair configuration gold electrodes, supported on a substrate, was considered for the sensing device; employed characterization technique where FTIR and SEM. The experimental results showed a p-type response of the sulfonated SWCNTs, with decrease in resistance, under exposure to NO gas (40⁻200 ppb) and NO₂ (40⁻200 ppb). Also, the sensor responses to successive exposures at NO₂ 800 ppb together with investigation of long term stability, at 485 ppb for NO, are reported. The reaction mechanism in case of NO and NO₂ detection with sulfonated SWCNTs is presented.