Plasmonically optimized gold–gallia nanocomposites: a novel approach for high-temperature NO2 detection†

Abstract

Monitoring gases in harsh environments in real-time has become indispensable across various industries such as nuclear plants, turbines, and boiler plants. Materials capable of withstanding high temperatures are essential for sensing platforms, often operating at temperatures exceeding 300 °C. Localized surface plasmon resonance based optical gas sensing, although promising, has a glaring limitation when sensing analytes that themselves interact with light in wavelength regimes that overlap with the material's resonance, which is remedied in one manner in this report. In this study, we synthesize multiple gold–gallium oxide nanocomposites that were evaluated for their morphological and optical stabilities at high temperatures (800 °C), post which they were tested for NO₂ detection at 800 °C, wherein temperature-dependent kinetic studies were conducted first to deconvolute the absorbance of NO₂ itself at different temperatures. The findings suggest that gold–gallium oxide nanocomposites prepared using the described solution-based approach show promising applications in high-temperature and extreme environment gas sensing.