Ppb-Level Ammonia Detection by Exfoliated WS 2 Based Chemiresistive Sensors for Breath Analysis

Sakhuja, N and Jha, R and Bhat, N (2018) Ppb-Level Ammonia Detection by Exfoliated WS 2 Based Chemiresistive Sensors for Breath Analysis. In: 17th IEEE SENSORS Conference, SENSORS 2018, 28 - 31 october 2018, New Delhi.

PDF SENSORS_2018.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

The sensing behavior of as-synthesized and annealed \mathbfWS-2 nanosheets towards Ammonia has been demonstrated in this study. The nanosheets were synthesized using liquid-phase exfoliation technique It was observed that sonication time affects the ammonia sensing performance and 3-6 hours sonicated samples showed good sensing performances with 5 hours sonicated sample showing optimal performance. The as-synthesized nanosheets based chemiresistive sensors showed reasonable response towards ammonia in the concentration range of 300 ppb (3.8) to 3 ppm (79.10) at an optimum temperature of 250°C. The response and recovery time were found to be 67 sand 87 s respectively. These samples were further annealed for two hours in itrogen ambient and this significantly enhanced the response by an order of magnitude for the highest concentration of 3 ppm, i.e. from 79.1 to 1805. The response and recovery time were found to be 125 sand 59 s. Though the linearity of the device response is affected by the annealing process, it enables the sensor to push the lowest limit of detection down to 50 ppb. A plausible mechanism has also been proposed for this sensor.

Item Type:	Conference Paper
Publication:	Proceedings of IEEE Sensors
Publisher:	Institute of Electrical and Electronics Engineers Inc.
Additional Information:	The copyright for this article belongs to the Institute of Electrical and Electronics Engineers Inc.
Keywords:	Annealing; Chemical sensors; Conductive plastics; Exfoliation (materials science); Nanosheets; Sulfur compounds; Tungsten compounds, Ammonia sensors; Chemiresistive sensors; Concentration ranges; Liquid exfoliations; Optimal performance; Plausible mechanisms; Response and recovery time; Tungsten disulfide, Ammonia
Department/Centre:	Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	29 Jul 2022 09:45
Last Modified:	29 Jul 2022 09:45
URI:	https://eprints.iisc.ac.in/id/eprint/75042

Actions (login required)

View Item