CCS and Power Systems
Crosscutting Research - University Training and Research
AOI: Development of Metal Oxide Nanostructure-Based Optical Sensors for Fossil Fuel Derived Gases Measurement at High Temperature
Project No: FE0003859
To advance the understanding of real-time gas composition analysis, NETL is partnering with the University of Pittsburgh to develop metal oxide nanostructure-based optical sensors for fossil fuel derived gas measurement at high temperatures.
Initially, a laser nanofabrication technique will be used to produce three-dimensional (3-D) structurally functional metal-oxide nanomaterials for high-temperature gas sensing. Metal oxides are of interest in materials research, due to the susceptibility in nanoengineering to produce photonic bandgaps, or wavelengths, at which photon transmission does not occur. Materials with this property are known as photonic crystals. Once the optical properties of these photonic crystals have been characterized, functional metal-oxide films will be integrated on two distinct hightemperature optical sensor platforms.
The porous metal-oxide photonic crystal will have a large surface area for gas adsorption. Changes in the photonic crystal’s surface chemistry due to gas adsorption result in changes to the refractive index, which can be interrogated remotely via transmission and reflection spectra. The bandgap and resonance wavelength of the photonic crystals will be characterized with the transmission characteristics as functions of the concentration and temperature of an introduced gas.
Second, using ultrafast laser and chemical regenerative techniques, temperature-stable fiber gratings in air-hole microstructured optical fibers as a sensor platform will be characterized. The traditional method of fabricating gratings in optical fibers fails at higher temperatures, thus, achieving a stable high-temperature platform is critical.
Both fiber Bragg gratings and long-period gratings will be produced and compared with the performance as sensor platforms. Sol-gel deposition will then be used to coat fiber grating devices with metal-oxide sensing materials. Further enhancement of sensitivity will also explore the development of fiber interferometers with and without gratings.
Thirdly, two methods of synthesizing various metal-oxide films on the inner wall of hollow-core capillary waveguides for gas sensing will be explored. Measurements will be taken using both Raman and photo-luminescence spectroscopy.