Gallium Plasmonic Nanoantennas Unveiling Multiple Kinetics of Hydrogen Sensing, Storage, and Spillover

Hydrogen is the key element to accomplish a carbon-free based economy. Here, first evidence of plasmonic gallium (Ga) nanoantennas provided as nanoreactors supported on sapphire (?-Al2O3) acting direct plasmon-enhanced photocatalyst for hydrogen sensing, storage, and spillover. The role plasmon-catalyzed electron transfer between Ga nanoparticle in activation those processes highlighted, opposed conventional refractive index-change-based sensing. This study reveals that, while temperature selectively operates various processes, longitudinal (LO-LSPR) transverse (TO-LSPR) localized surface plasmon resonances nanoparticles open selectivity reaction pathways at specific sites corresponding electromagnetic hot-spots. Specifically, TO-LSPR couples light into dissociative adsorption formation hydrides, whereas LO-LSPR activates heterogeneous reactions interface with support, that is, spillover ?-Al2O3 reverse-oxygen from ?-Al2O3. Ga-based plasmon-catalytic platform expands application plasmon-catalysis technologies, including reversible fast sensing timescale few seconds limit detection low 5 ppm broad range room-temperature up 600 °C remaining stable reusable over an extended period time.