【Device Papers】β-Ga₂O₃/rGO Composite based Near Room Temperature and Highly Selective Methyl Salicylate Sensing

      Researchers from Indian Institute of Technology Dharwad have published a dissertation titled " β-Ga₂O₃/rGO Composite based Near Room Temperature and Highly Selective Methyl Salicylate Sensing " in Materials Research Bulletin.

Abstract

      Portable gas sensors are critical for on-site, sensitive, and cost-effective detection of volatile organic compounds (VOCs) for various applications, including agriculture and cosmetics sectors. Methyl salicylate (MeSA), a VOC emitted by stressed crops and widely used in cosmetic products for its fragrance and anti-inflammatory effects, needs to detected for monitoring plant health and product safety. In this work, β-Ga₂O₃ nanocubes were synthesized via a simple hydrothermal method and mixed with reduced graphene oxide (rGO), synthesized using a chemical route, to synthesize a β-Ga₂O₃/rGO composite resistive sensor. Field emission scanning electron microscope confirmed the morphologies, while UV–Vis absorbance and Tauc’s plots revealed a reduction in band gap from 5.5 eV for β-Ga₂O₃ to 3.6 eV for the composite, indicating strong electronic interactions. Preliminary sensing tests demonstrated optimal performance at 40°C for the β-Ga₂O₃/rGO composite, with sensor response increasing from 1.6 to 6.3 for 19–250 ppm MeSA. The sensor showed high selectivity towards MeSA against common interferents such as CO, NH₃, NO₂, CO₂, and β-caryophyllene.

DOI：

https://doi.org/10.1016/j.materresbull.2026.114280