High performance NO2 sensor using MoS2 nanowires network

• Published in: Applied physics letters Vol. 112; no. 5
• Main Authors: Kumar, Rahul, Goel, Neeraj, Kumar, Mahesh
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 29.01.2018
• Subjects: Applied physics; Chemical synthesis; Crystal structure; Fluid dynamics; Intersections; Molybdenum disulfide; Morphology; Nanowires; Nitrogen dioxide; Organic chemistry; Potential barriers; Raman spectroscopy; Scanning electron microscopy; Sensitivity enhancement; Sensors; Spectrum analysis; Turbulent flow; X ray photoelectron spectroscopy; X-ray diffraction
• DOI: 10.1063/1.5019296
• ISSN: 0003-6951

We report on a high-performance NO2 sensor based on a one dimensional MoS2 nanowire (NW) network. The MoS2 NW network was synthesized using chemical transport reaction through controlled turbulent vapor flow. The crystal structure and surface morphology of MoS2 NWs were confirmed by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Further, the sensing behavior of the nanowires was investigated at different temperatures for various concentrations of NO2 and the sensor exhibited about 2-fold enhanced sensitivity with a low detection limit of 4.6 ppb for NO2 at 60 °C compared to sensitivity at room temperature. Moreover, it showed a fast response (16 s) with complete recovery (172 s) at 60 °C, while sensitivity of the device was decreased at 120 °C. The efficient sensing with reliable selectivity toward NO2 of the nanowires is attributed to a combination of abundant active edge sites along with a large surface area and tuning of the potential barrier at the intersections of nanowires during adsorption/desorption of gas molecules.