GS9.4 - Optical Hydrogen Sensing with Tungsten Oxide Photonic Crystals
- Event
- 17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria - Chapter
- Gas Sensors 9 - Hydrogen Sensing
- Author(s)
- S. Amrehn, X. Wu, T. Wagner - Paderborn University, Paderborn (Germany)
- Pages
- 328 - 329
- DOI
- 10.5162/IMCS2018/GS9.4
- ISBN
- 978-3-9816876-9-9
- Price
- free
Abstract
A hydrogen sensor with optical read out based on a photonic crystal is presented. The position of the photonic band gap of a tungsten oxide inverse opal (loaded with platinum) is used as an optical sensor signal to detect hydrogen. To explain the sensor behavior, the mechanism of intercalation of hydrogen into the tungsten oxide lattice, the formation of tungsten bronze, and the back reactions are investigated. This reactions cause a refractive index change of the solid phase and so the photonic band gap shifts. The photonic band gap is, besides others, determined by the refractive index contrast of the two periodically arranged materials, which form the photonic crystal. Also cross-sensitivities for typical gases, like methane, carbon monoxide and humidity are shown. Due to the specific intercalation mechanism for hydrogen the selectivity of the presented system is high.