Ethanol gas sensing properties of hydrothermally grown α-MnO2 nanorods

In the present work, nanorods of alpha-manganese dioxide (alpha-MnO2 NRs) have been successfully synthesized using simple and cost-effective hydrothermal method, which further are utilized as a potential ethanol gas sensing material. As-synthesized alpha-MnO2 NRs are characterized for their structure and morphology by means of X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, and atomic force microscopy measurement techniques, respectively. Structural elucidation confirms the formation of phasepure tetragonal alpha-MnO2. Randomly distributed alpha-MnO2 NRs demonstrate average diameter of similar to 50 -60 nm and length similar to 1-1.5 mm. Gas sensing properties of alpha-MnO2 NRs carried out systematically, as a function of time, towards various target gases and operating temperatures, corroborate excellent selectivity towards ethanol at 180 degrees C as an optimum operating temperature in addition to detect as little as 10 ppm ethanol gas. Furthermore, alpha-MnO2 NRs sensor shows the superior reproducibility and stability in response upon consecutive exposure of ethanol at 180 degrees C. Gas sensing study reveals the applicability of alpha-MnO2 NRs as a promising sensing material in the developing ethanol-based gas sensors. (C) 2017 Elsevier B.V. All rights reserved.