【Device Papers】Highly selective ammonia gas sensor using Ga₂O₃/MoO₃ nanocomposite at ambient atmospheric conditions

      Researchers from the University of Mysore have published a dissertation titled "Highly selective ammonia gas sensor using Ga₂O₃/MoO₃ nanocomposite at ambient atmospheric conditions" in Materials Science and Engineering: B.

Abstract

      The β-Ga₂O₃ and MoO₃ nanocomposite with varying concentration of MoO₃ at 2.5 %, 5 % and 7.5 % were synthesized through hydrothermal method followed by physical mixing. Obtained nanocomposites were characterized to study its morphological, structural and optical properties through XRD, SEM, EDAX, TEM, XPS and UV–Visible spectroscopy. Surface area analysis was done using BET analysis method. Ammonia (NH₃) sensing studies were conducted at room temperature for synthesized composites. Nanocomposite with increased MoO₃ concentration showed increase in the response towards ammonia detection and highest response of 420.12 % for 100 ppm NH₃ at relative humidity (RH) of 69 % with response and recovery time of 53.75 s and 27.44 s respectively. Studies on humidity dependent sensing have been conducted for the same synthesized nanocomposites. The enhanced sensing of NH₃ in room temperature is attributed to sensing mechanism mediated by the adsorbed humidity and oxygen on the surface of the sensing material in addition to the chemical and electronic sensitization effects.

DOI：

https://doi.org/10.1016/j.mseb.2025.119027