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

•Dielectric nanocomposite comprising P-MWCNT and a low molecular weight organic diphenylethylenediamine stabilised with an acrylate resin is designed for realizing CO2 detection at room temperature.•Small amount (0.5wt%) of P-type multi-walled carbon nanotube in DPED dramatically improves the CO2 sensitivity by ∼100 times.•Sensitivity improvement is duo to significantly improved transformation of amine to carbamate in CO2 atmosphere with the P-MWCNT.