Studying the humidity sensing behavior of MWCNTs boosted with Co3O4 nanorods

For the development of humidity sensors, multiwall carbon nanotubes boosted with cobalt oxides nanorods (MWCNTs/Co3O4) has been prepared by precipitation method to be utilized in humidity sensing application. To evaluate the prepared materials quality, both of functionalized MWCNTs and MWCNTs boosted with Co3O4 nano rods are characterized by High Resolution Transmission Electron Microscope (HRTEM), X- ray powder diffraction (XRD), thermal analysis (DTA and TGA), Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectroscopy. Meanwhile the humidity sensing behavior was also investigated. The proposed composite was tested in the wide range in relative humidity and testing frequency. The obtained results confirmed that the optimum testing frequency is 50 Hz. The MWCNTs/Co3O4 nanocomposite exhibited a good sensitivity toward humidity from 11% up to 97% RH with reasonable response and recovery time. Also, the sensor revealed a low hysteresis and good repeatability with increasing and decreasing of humidity levels.

Automated summary

The MWCNTs/Co3O4 nanocomposite showed good sensitivity to humidity over a wide range of relative humidity, with a reasonable response and recovery time. The sensor also exhibited low hysteresis and good repeatability with changes in humidity levels. The optimum testing frequency was determined to be 50 Hz.