Bimetallic Nanoparticle-Based Localized Surface Plasmon Resonance for Enhanced Sensitivity of Reflective Fiber Optic H2 Sensing

In this work, we demonstrate a reflection-based nanocomposite-functionalized fiber H-2 sensor for ease of installation and H-2 sensing in energy storage, fuel cells, electrolyzers, and other similar devices. High-temperature H-2 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 H-2 concentration and cycling gas conditions. In response to reducing H-2, 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 H-2 environment at high temperatures.