Ultra-high performance of PPy/MoS2 2D nanocomposites for ammonia sensing

Abstract

The synergistic interaction between Polypyrrole/Molybdenum disulfide at the interface makes their nanocomposites ideal for gas sensing applications. In this work, PPy/MoS2 (1 wt%, 5 wt%, 10 wt%, 20 wt% and 30 wt%) based nanocomposites have been prepared by in-situ chemical oxidative polymerization of pyrrole. In these nanocomposites, pyrrole acts as a matrix component and MoS2 as filler, which is finally loaded on interdigitated electrodes. In a significant development for large-scale production, the gas sensor fabrication process was designed to be both cost-effective and easy to operate. This paves the way for wider commercialization. The optimized sensor made from PPy and MoS2 with 5 wt% of MoS2, demonstrates excellent sensing performance. It has a sensitivity of 21.65 % for 100 ppm gas exposure, along with fast response and recovery times of 340 seconds and 680 seconds, respectively. It also shows a high response towards NH3 compared with pure PPy. In addition, high repeatability and long-term stability of prepared nanocomposites have also been observed over a concentration range of 10–200 ppm. This material stands out for its strong response to ammonia gas compared to other detectable gases. These results render the PPy/MoS2 nanocomposite a promising candidate for high-performance NH3 sensing at 28 ̊C. The underlying sensing mechanism of the PPy/MoS2 sensing device towards NH3 gas was systematically discussed which is attributed to the synergistic effect of binary nanocomposites.