Synthesis and Characterization of Polymeric Graphene Quantum Dots Based Nanocomposites for Humidity Sensing

Abstract EN

Graphene quantum dots (GQDs) were synthesized and incorporated with polyethylenedioxythiophene:poly(4-styrenesulfonate) (PEDOT:PSS) and carbon nanotube (CNT) to form a composite that can be used for humidity sensors.

The 600 nm thick composite films contained bulk heterojunctions of CNT/GQD and CNT/PEDOT:PSS.

The sensors made from the composites responded well to humidity in a range from 60 to 80% at room temperature and atmospheric pressure.

With a CNT content of 0.4 wt.% (GPC-1) to 0.8 wt.% (GPC-2) and 1.2 wt.% (GPC-3), the sensitivity of the humidity sensing devices based on CNT-doped graphene quantum dot-PEDOT:PSS composites was increased from 4.5% (GPC-1) to 9.0% (GPC-1) and 11.0% (GPC-2), respectively.

The fast response time of the GPC sensors was about 20 s and it was much improved due to CNTs doping in the composites.

The best value of the recovery time was found to be of 40 s, for the GPC composite film doped with 1.2 wt.% CNT content.