Nanodisc Decorated W-WO x Suspended Nanowire: A Highly Sensitive and Selective H2S Sensor

Benedict, S and Bhat, N (2019) Nanodisc Decorated W-WO x Suspended Nanowire: A Highly Sensitive and Selective H2S Sensor. In: IEEE Sensors Journal, 19 (6). pp. 2023-2030.

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Abstract

In this paper, we report room temperature synthesis of plasma oxidized, suspended tungsten-tungsten oxide (W-WO x ) core-shell nanowire for sensing ppb level H 2 S. The electric field modulation at the W-WO x interface of the core-shell nanowire strongly influences the sensing performance and brings down the operating temperature all the way down to 50 °C, compared to completely oxidized (WO x ) nanowire. The optimum interface ratio (W/WO x ) of the nanowire shows response of 90.4 (1 ppm) with six months of response stability and excellent selectivity. The limit of detection of 10 ppb with response and recovery time of 4 and 46 s, respectively, is achieved. To enhance the response further, we utilize nanostructuring on top of nanowire, using nanodiscs of 20, 50, and 100 nm diameter and 10 nm height. The nanowire with nanodiscs of 20 nm diameter shows high repeatable response of 12529 (1 ppm) at 150 °C and fast response and recovery times of 12 and 19 s with detection limit of 0.5 ppb. As we switch from unpatterned to patterned nanowire, the observed change in H 2 S sensing characteristics indicates that the core-shell nanowire behavior makes a transition from p-type to n-type. Extensive material characterization is done using UV-Vis spectroscopy, XPS, and TEM.

Item Type:	Journal Article
Publication:	IEEE Sensors Journal
Publisher:	Institute of Electrical and Electronics Engineers Inc.
Additional Information:	The copyright for this article belongs to Institute of Electrical and Electronics Engineers Inc.
Keywords:	Catalyst selectivity; Electric fields; Oxidation; Shells (structures); Tungsten compounds; Ultraviolet visible spectroscopy, Core-shell nanowires; Electric field modulation; Material characterizations; Nanodiscs; Plasma oxidation; Response and recovery time; Room temperature synthesis; suspended, Nanowires
Department/Centre:	Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	28 Nov 2022 09:21
Last Modified:	28 Nov 2022 09:21
URI:	https://eprints.iisc.ac.in/id/eprint/78297

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