An enhanced flexible room temperature ammonia gas sensor based on GP-PANI/PVDF multi-hierarchical nanocomposite film.

[Display omitted] • Flexible GP-PANI/PVDF film with multi-hierarchical porous structure. • The sensor with 10% response to 100 ppb NH 3 at room temperature. • Graphene as additives enhancing the flexibility of the sensor. • Three synergistical roles effect on the film's high NH 3 sensing performance. Resistive-type polyaniline (PANI) based sensing film was fabricated by a simple in-situ polymerization method with graphene (GP) as additives on flexible porous polyvinylidene fluoride (PVDF) substrate. The fabricated flexible GP-PANI/PVDF membrane demonstrates a multi-hierarchical porous microstructure, enhancing its sensing performance towards ammonia (NH 3). The optimized GP-PANI/PVDF sensor shows 60% response towards 1 ppm NH 3 with a response time of 46 s, and 10% response towards 0.1 ppm NH 3 at 24℃, respectively. Moreover, the GP-PANI/PVDF sensor presents excellent flexibility, exhibiting only small response values' difference upon several bending angles and after 1500 bending/extending cycles. Besides, the GP-PANI/PVDF sensor exhibits a strong linear relationship between the NH 3 response values and working temperatures with a range of 24℃∼50℃. The results demonstrate that the flexible GP-PANI/PVDF film sensor holds great promise for the application of portable, lightweight, and room temperature sub-ppm level NH 3 detection devices. [ABSTRACT FROM AUTHOR]