Specific NH3 Gas Sensor Worked at Room Temperature Based on MWCNTs-OH Network
Functionalized Multi-Walled Carbon Nanotubes (MWCNTs-OH) network with thickness 4μm was made by the vacuum filtration from suspension (FFS) method. The morphology, structure and optical properties of the MWCNTs film were characterized by SEM and UV-Vis. spectra techniques. The SEM images reflected highly ordered network in the form of ropes or bundles with close-packing which looks like spaghetti. The absorbance spectrum revealed that the network has a good absorbance in the UV-Vis. region. The gas sensor system was used to test the MWCNT-OH network to detect NH3 gas at room temperature. The resistance of the sensor was increased when exposed to the NH3 gas. The sensitivities of the network were 1.3% at 14ppm, 3.3% at 27ppm and 6.13% at 68ppm. The sensor is specifically sensitive to NH3 gas and does not affect by the amount of ambient air.
A. H. Al-Husseini et al., "Specific NH3 Gas Sensor Worked at Room Temperature Based on MWCNTs-OH Network", Nano Hybrids and Composites, Vol. 23, pp. 8-16, 2018