Figure 1

Scheme of the indirect nanoplasmonic hydrogen sensing platform. The localized surface plasmon resonance (LSPR) of gold nanodisks is used as “a sensor” to characterize a material which undergoes some change upon hydrogen absorption. The latter material (Pd nanoparticles in the present work) is deposited onto a thin dielectric spacer layer, separating the optically active sensor nanodisks from the material to be studied and the hydrogen environment. The change of hydrogen concentration in Pd nanoparticles is detected trough coupling of the enhanced plasmonic near field of the Au nanodisk plasmons to the changing dielectric properties of Pd nanoparticles upon H absorption and desorption. The TEM images below show three examples of Pd nanoparticles, with the corresponding histograms of the size distribution.Reuse & Permissions

Figure 2

Experimental hydriding (left column) and dehydriding (right column) kinetics for three mean diameters: $D=1.81$ (a), 2.47 (b), and 5.35 nm (c) of Pd nanoparticles. The change of the optical extinction, measured at 640 nm, is normalized in such a way that “1” corresponds to 100% conversion of Pd nanoparticles to the hydride phase.Reuse & Permissions

Figure 3

(a) Power-law scaling of $t_{0.5}$ and $D$ for hydriding. The linear fit corresponds to $z=2.9$. (b) $\ln (t_{0.5})$ as a function of $R$ for dehydriding. The solid line represents the best fit according to Eq. (4), yielding $R_{*}=3.9\mathrm{nm}$. The error bars are calculated based on 4 independent hydriding and dehydriding kinetic measurements on each sample.Reuse & Permissions