Pt/MoS₂/Polyaniline Nanocomposite as a Highly Effective Room Temperature Flexible Gas Sensor for Ammonia Detection

Abstract

A Pt/MoS2/polyaniline (Pt/MoS2/PANI) nanocomposite is successfully synthesized by the hydrothermal process combined with the in situ polymerization method, and then Pt particles are decorated on its surface. The Pt/MoS2/PANI nanocomposite is deposited on a flexible Au-interdigitated electrode of a polyimide (PI) film. The flexible sensor exhibits a higher response value and fast response/recovery time to NH3 at room temperature (RT). It results in 2.32-fold and 1.13-fold improvement in the gas-sensing response toward 50 ppm NH3 compared to those of PANI and MoS2/PANI-based gas sensors. The detection limit is 250 ppb. The enhancement sensing mechanisms are attributed to the p–n heterojunction and the Schottky barrier between the three components, which has been confirmed by the current–voltage (I–V) curves. A satisfactory selectivity to NH3 against trimethylamine (TMA) and triethylamine (TEA) is obtained according to density functional theory (DFT), Bader’s analysis, and differential charge density to illustrate the adsorption behavior and charge transfer of gas molecules on the surface of the sensing materials. The sensor retains the excellent sensing response value even under high relative humidity and sensing stability at higher bending angle/numbers to NH3 gas. Hence, Pt/MoS2/PANI can be regarded as a promising sensing material for high-performance NH3 detection at room temperature applied in flexible wearable electronics.

Capping Ligand Engineering Enables Stable CsPbBr3 Perovskite Quantum Dots toward White-Light-Emitting Diodes

“…In order to improve the thermal stability of PeQDs as well as photoluminescence quantum yield (PLQY), tremendous energy has been invested in this project, such as Cs/Pb site doping − and surface engineering. − Among them, capping ligand engineering is an effective method to tune capping ligands sitting on PeQDs, , simultaneously passivating surface defects , and improving the stability of PeQDs. Specifically, Zeng et al effectively synthesized CsPbBr 3 PeQDs via a controlled thermal injection technique utilizing tetraoctylammonium bromide which exhibits a long chain structure serving as the source of Br and restraining the likelihood of exciton trapping caused by bromide vacancies.…”

PANI/CoMoO4 Nanocomposite Heterostructures for Detection of NH3 at Room Temperature

“…In order to further explain the response mechanism of the PANI/CoMoO 4 sensor, theoretical calculation was used for detailed analysis (more details in the Supporting Information). The charge density, redistribution charge transfer, and adsorption behavior of ammonia and oxygen to PANI and PANI/CoMoO 4 (002) were evaluated by means of the Vienna Ab Initio Simulation Package (VASP) using density functional theory and Bader analysis. − Figure a shows the side view of theoretical models of PANI and PANI/CoMoO 4 (002). The heterointerface is closely linked with the sensing mechanism.…”

2D V2C MXene Based Flexible Gas Sensor for Highly Selective and Sensitive Toluene Detection at Room Temperature

“…1,2 To overcome these drawbacks, flexible gas sensors have recently gained considerable attention among the research communities for their usage in wearable electronics like smartwatches, bands, human skins, robots, and so on because of their attractive properties, including low-cost, lightweight, compactness, and real-time monitoring of toxic gases without any requirement of special conditions. 3,4 Flexible gas sensors are usually made up of electrodes, sensing materials, and a flexible substrate. Paper, polyethylene naphthalate, poly(ethylene terephthalate) (PET), polyimide, poly(dimethylsiloxane), polyester film, etc., are the substrates that are most often employed because of their unique properties such as biocompatibility, portability, flexibility, and so forth.…”