Potential to Detect Hydrogen Concentration Gradients with Palladium Infused Mesoporous-Titania on D-Shaped Optical Fiber

Zsolt L Poole; Paul R Ohodnicki; Aidong Yan; Yuankun Lin; Kevin P Chen

doi:10.1021/acssensors.6b00583

Potential to Detect Hydrogen Concentration Gradients with Palladium Infused Mesoporous-Titania on D-Shaped Optical Fiber

ACS Sens. 2017 Jan 27;2(1):87-91. doi: 10.1021/acssensors.6b00583. Epub 2016 Dec 19.

Authors

Zsolt L Poole¹, Paul R Ohodnicki², Aidong Yan¹, Yuankun Lin³, Kevin P Chen¹

Affiliations

¹ Department of Electrical and Computer Engineering, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States.
² National Energy Technology Laboratory , 626 Cochrans Mill Road, Pittsburgh, Pennsylvania 15236, United States.
³ Department of Physics, University of North Texas , Denton, Texas 76203, United States.

PMID: 28722436
DOI: 10.1021/acssensors.6b00583

Abstract

A distributed sensing capable high temperature D-shaped optical fiber modified with a palladium nanoparticle sensitized mesoporous (∼5 nm) TiO₂ film, is demonstrated. The refractive index of the TiO₂ film was reduced using block copolymer templating in order to realize a mesoporous matrix, accommodating integration with optical fiber. The constructed sensor was analyzed by performing direct transmission loss measurements, and by analyzing the behavior of an integrated fiber Bragg grating. The inscribed grating should reveal whether the refractive index of the composite film experiences changes upon exposure to hydrogen. In addition, with frequency domain reflectometry the distributed sensing potential of the developed sensor for hydrogen concentrations of up to 10% is examined. The results show the possibility of detecting chemical gradients with sub-cm resolution at temperatures greater than 500 °C.

Keywords: Rayleigh backscatter; distributed sensing; gradient sensing; hydrogen sensing; mesoporous film; optical fiber sensing; palladium nanoparticles; refractive index engineering.