Chemical bath deposition of h-MoO3 on optical fibre as room-temperature ammonia gas sensor

Chua, Wen Hong and Yaacob, Mohd Hanif and Tan, Chou Yong and Ong, Boon Hoong (2021) Chemical bath deposition of h-MoO3 on optical fibre as room-temperature ammonia gas sensor. Ceramics International, 47 (23). pp. 32828-32836. ISSN 0272-8842, DOI

Full text not available from this repository.


This study successfully developed a semiconductor metal oxide-based ammonia gas sensor that was powered by an Ultraviolet-Visible-near-IR optical light source. However, optical fibre gas sensors using single metal oxide nanomaterial are limited. To address this situation, a h-MoO3 nanorod was grown on a tapered region of optical fibre glass using a simple chemical bath deposition to form a unique sensing element. An additional annealing treatment was then performed to modify the oxidation state of h-MoO3. The property changes of the samples were characterised using different techniques, such as FESEM, TEM, XRD, XPS, TGA and UV-Vis. Overall, the annealing treatment improved the sensitivity performance, response and recovery time of the sensor towards NH3. h-MoO3 that was annealed at 150 degrees C in air showed stable room temperature absorbance responses of 0.05, 0.18, 0.22, 0.28 and 0.35, a fast response time of 210 s towards 500 ppm of NH3 and strong stability and repeatability. The optical NH3 gas-sensing behaviour was significantly correlated with the non-stoichiometric Mo5+ content. The chemisorbed oxygen species and physiosorbed NH3 altered the refractive index and its absorption coefficient on the nanorod, which manipulated the optical signal and acts as a sensing mechanism. These results verify that a chemical bath deposition growth of the h-MoO3 nanorod exhibits a promising optical sensing characteristic, which paves a path for emerging gas-sensing technology.

Item Type: Article
Uncontrolled Keywords: Chemical bath deposition; h-MoO3 nanorods; Non-stoichiometric Mo5+; Free carriers' absorption; Optical gas sensor
Subjects: T Technology > TA Engineering (General). Civil engineering (General)
T Technology > TP Chemical technology
Divisions: Faculty of Engineering
Depositing User: Ms. Juhaida Abd Rahim
Date Deposited: 23 Feb 2022 07:47
Last Modified: 23 Feb 2022 07:47

Actions (login required)

View Item View Item