Investigation of plasmonic based nanocomposite thin films for high temperature gas sensing

Plasmonic based thin metal oxide films embedded with Au nanoparticles (AuNPs) have been employed as sensing materials for detection of H2 and CO2 gases at high temperature and an oxygen free environment. Applications of this sensing technology include solid oxide fuel cells (SOFCs) as well as high temperature harsh environments which might be oxidizing or reducing in nature. In situ detection of H2, CO2, CO, CH4, and water vapor at the inlet stream of solid oxide fuel cell is important for its efficient operation. Existing sensors have several prominent limitations such as poor dynamic range, poor stability, slow response time, and inability to accurately detect one or several gases of interest in the presence of numerous interferences and contaminants. Materials with good sensitivity, selectivity and thermal stability for rapid reliable detection and monitoring of gases is still a necessity. In this work, the localized surface plasmon response (LSPR) of AuNPs embedded in metal oxide is investigated for detection of H2 and CO2. Firstly, CeO2 supported AuNP sample is employed for percent level detection of H2 and CO2. The study is extended to H2 sensing in a CO2 / N2 carrier gas as well as CO2 sensing in a H2 / N2 carrier gas. Additionally, H2 pretreatment and increased temperature showed a signature response for CO2 on Au-CeO2 film. These sensors should complement existing instruments in situations when multi-point or distributed measurements are needed and as such sensors with demonstrated stability, selectivity and sensitivity will ensure a series of parallel measurements for enhanced system control.