Ultrasensitive flexible NH3 gas sensor based on polyaniline/SrGe4O9 nanocomposite with ppt-level detection ability at room temperature

By Yajie Zhang, Junxin Zhang, Yadong Jiang, Zaihua Duan, Bohao Liu, Qiuni Zhao, Si Wang, Zhentao Yuan, Huiling Tai. 2020

180 citations recorded by the source corpus.

Abstract Detection limit as an important parameter of gas sensors, much effort has been devoted to developing high-performance gas sensors with low detection limit. However, the development of gas sensors with ppt-level detection limit still faces enormous challenges. In this work, a flexible and ultra-highly sensitive ammonia (NH3) sensor based on polyaniline/SrGe4O9 nanocomposites (PSN) was successfully fabricated via a facile in situ chemical oxidation polymerization method. When exposed to 0.2–10 ppm NH3 at 25 °C in 60% relative humidity (RH), the PSN sensor showed larger sensitivity (20.59% ppm−1) than that of PANI sensor (9.82% ppm−1). The response of the PSN sensor (16%) was two-fold higher than that of the PANI one (8%) to 0.2 ppm NH3 at room temperature. Meanwhile, the response time of the PSN sensor (24 s) was reduced to up to a third of that of the PANI sensor (64 s) for 800 ppb NH3. Additionally, the flexible PSN sensor exhibited good reproducibility, satisfactory long-term stability, excellent selectivity and outstanding flexibility to NH3 at room temperature. Significantly, the PSN sensor presented the ultra-low detection limit of 250 ppt toward NH3. Such outstanding gas-sensing properties were attributed to the unique hierarchical architecture with abundant mesoporous and the formation of p-n heterojunction at the interface between p-type PANI and n-type SrGe4O9. This research provides new strategies for developing high-performance NH3 sensors with supersensitive and ultra-low detection limit.

Subfields: Bioengineering, Biomedical Engineering, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/643a00305eb0e2fea90b9b8980b52d335a07103e