Intrinsically Safe Optical Fiber Hydrogen Sensor Using Pt-SiO2 Coated Long-Period Fiber Grating

Abstract

Hydrogen, a promising clean energy carrier, needs safe detection due to its flammability. Conventional electrical hydrogen sensors have drawbacks like high operating temperatures, poor selectivity and ignition risks. We propose an optical sensor using long-period fiber gratings (LPGs) coated with Pt-SiO2 nanomaterials. It works via catalytic reaction: H2 reacts with O2 on Pt nanoparticles, releasing heat that shifts LPG’s resonant wavelength. Structural characterization showed porous SiO2 with uniform Pt, ensuring efficiency and stability. Experiments proved it sensitively responds to 0.5–2.5% H2 (max wavelength shift 7.544 nm), with fast response/recovery, good repeatability/reversibility. Logistic fitting (R2 = 0.999) confirmed strong correlation. This sensor, safe, sensitive and stable, has great potential for real-time H2 monitoring in critical environments.