Adsorption-based model for single-wall carbon nanotube response to NO2 gas

Abstract

In this work, the response of single-wall carbon nanotube as a resistive NO2 sensor was investigated. A model was developed based on the Freundlich adsorption isotherm and a multi-exponential function was used to describe the relationship between the sensor response and the gas concentration. The model predicts both static and dynamic responses in a closed sampling system. In addition, the model considers the effect of different variables such as the operating temperature, NO2 concentration in air and the two phases (adsorption and desorption) of response. The developed model is in good accordance with the experimental data. This model could be used to design new environmental detection devices and interpret experimental data by providing some insight into the sensor behaviour during the transient phase.