A Thermoelectric-Driven nitrogen dioxide gas sensor based on Multiwall carbon Nanotube/Polypyrrole composites

• A thermoelectric—driven NO 2 gas sensor based on MWCNT/PPy was developed. • PPy plays a dual role: a gas-sensing material detecting NO 2 , and a thermoelectric material generating power to supply the sensor. • Incorporation of 0.375 wt% MWCNT boosts NO₂ adsorption capacity by 207% and increases the Seebeck coefficient by 42.05%. • The maximum response to 300 ppm NO₂ hits 55.50% at 0.375 wt% MWCNT doping, 5.35 times the undoped sample. Nitrogen dioxide (NO 2 ) gas sensors commonly suffer from h