Hydrogen sensing performance of silica microfiber elaborated with Pd nanoparticles

A hydrogen sensor has been proposed by coating Pd nanoparticles-PMMA composite organic sol on silica microfiber independent on any expensive or complex chemical process. The thickness of cladding layer and the diameter of elaborated microfiber were determined as ∼20 μm and ∼57.93 μm, respectively. Due to the evanescent wave excited by silica microfiber and the amorphous structure of PMMA film, the Pd nanoparticles effectively absorbed the hydrogen molecules and resulted in the shift of resonance wavelength. The experimental results match well with an exponential curve with an average sensitivity of 5.58 nm/%, which is comparable to other electrochemical hydrogen sensors reported recently.