Dielectric nanocomposite of diphenylethylenediamine and P-type multi-walled carbon nanotube for capacitive carbon dioxide sensors

Abstract Dielectric nanocomposite comprising P-type multi-walled carbon nanotube and low molecular weight organic (1 R ,2 R )-(+)-1,2-diphenylethylenediamine, which is stabilised with an acrylate resin, is prepared and used as a sensing layer for capacitive carbon dioxide sensor operated at room temperature. It is found that adding a small amount (0.5 wt%) of P-type multi-walled carbon nanotube in diphenylethylenediamine can dramatically improve the CO 2 sensitivity by ∼100 times. The P-type multi-walled carbon nanotube significantly increases the transformation rate of amine to carbamate in CO 2 atmosphere as a catalyst for the chemical interactive sensing mechanism. In addition, P-type multi-walled carbon nanotube substantially improves temperature and humidity cross-sensitivities. The results show that the dielectric nanocomposite of diphenylethylenediamine and P-type multi-walled carbon nanotube is promising for capacitive carbon dioxide sensing application with ppm sensitivity at room temperature.