A nanostructured Al-doped ZnO as an ultra-sensitive room-temperature ammonia gas sensor

Bantikatla Himabindu; N S M P Latha Devi; Pothukanuri Nagaraju; Bhogoju Rajini Kanth

doi:10.1007/s10854-023-10337-6

A nanostructured Al-doped ZnO as an ultra-sensitive room-temperature ammonia gas sensor

J Mater Sci Mater Electron. 2023;34(12):1014. doi: 10.1007/s10854-023-10337-6. Epub 2023 Apr 22.

Authors

Bantikatla Himabindu^{1

2}, N S M P Latha Devi², Pothukanuri Nagaraju³, Bhogoju Rajini Kanth⁴

Affiliations

¹ Department of H&S, Sreyas Institute of Engineering and Technology, Hyderabad, 500068 Telangana India.
² Department of Engineering Physics, Koneru Lakshmaiah Educational Foundation, Guntur, 522302 Andhra Pradesh India.
³ Department of Physics, Sreenidhi University, Hyderabad, 501301 Telangana India.
⁴ LSMS, Department of Physical Sciences, T.K.R. College of Engineering and Technology, Hyderabad, 500097 Telangana India.

Abstract

Novel chemi-resistive gas sensors with strong detection capabilities operating at room temperature are desirable owing to their extended cycle life, high stability, and low power consumption. The current study focuses on detecting NH₃ at room temperature using lower gas concentrations. The co-precipitation technique was employed to produce pure and Al-doped ZnO nanoparticles, which were calcined at 300 °C for three hours. The effect of aluminium (Al) doping on the structural, morphological, optical, and gas-sensing abilities was investigated and reported. The presence of aluminium was confirmed by XRD, EDX, and FTIR spectroscopy. Additionally, to assess the various characteristics of Al-doped ZnO nanoparticles, scanning electron microscopy (SEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS), atomic force microscopy (AFM), and Brunauer-Emmett-Teller (BET) techniques were used. The crystallite size increased from 14.82 to 17.49 nm in the XRD analysis; the SEM pictures showed a flower-like morphology; and the energy gap decreased from 3.240 to 3.210 eV when Al doping was raised from 1 wt% to 4 wt%. AFM studies revealed topographical information with significant roughness in the range of 230-43 nm. BET analysis showed a mesoporous nature with surface areas varying from 25.274 to 14.755 m²/g and pore diameters ranging from 8.34 to 7.00 nm. The sensing capacities of pure and Al-doped ZnO nanoparticles towards methanol (CH₃OH), toluene (C₇H₈), ethanol (C₂H₅OH), and ammonia (NH₃) were investigated at room temperature. The one-wt% Al-doped ZnO sensor demonstrated an ultrafast response and recovery times at one ppm compared to other AZO-based sensors towards NH₃.

© The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2023, Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.