Bimetallic nanoparticle-based localized surface plasmon resonance for enhanced sensitivity of reflective fiber optic H2 sensing

Abstract

In this work, we demonstrate a reflection-based nanocomposite-functionalized fiber H2 sensor for ease of installation and H2 sensing in energy storage, fuel cells, electrolyzers, and other similar devices. High-temperature H2 fiber probes decorated with Au-Pt bimetallic alloy nanoparticles (NPs) in rutile titania matrix are characterized with scanning electron microscopy (SEM) and grazing incidence X-ray diffraction (GIXRD), and tested experimentally with varying H2 concentration and cycling gas conditions. In response to reducing H2, fully reversible reflectance intensity changes at the alloy NPs' localized surface plasmon resonance (LSPR) absorption peak are demodulated in real-time. The reflection fiber probe coated with bimetallic Au-Pt NPs in titania show 15x higher sensitivity than corresponding monometallic Au NPs in titania. The demonstration of reflection hydrogen fiber probe provides an installation advantage in various reactor environment applications, and the investigation of the Au-Pt binary alloy system unfolds new sensitivity-enhancing pathways for NP-based LSPR modulation in reducing H2 environment at high temperatures.

Plasmonic and interferometric optical fiber sensors for electrical system monitoring applications

“…In the case of chemical sensing applications, Au-nanoparticle incorporated nanocomposite films have been investigated for a range of analytes including H 2 , CO, CH 4 , CO 2 , and others [12], [34]- [36]. For inorganic metal oxide matrices, sensing responses have been reported at elevated temperatures such that oxidation and reduction reactions can result in electronic charge transfer with the matrix and ultimately the plasmonic Au nanoparticles [37]- [40]. However, for sensing under electrical asset monitoring conditions which typically involve temperatures of approximately 150 o C and below in normal operational conditions, alternative nanocomposite sensing layers have been investigated with success.…”