Optical readout of hydrogen storage in films of Au and Pd

Nishijima, Yoshiaki; Shimizu, Shogo; Kurihara, Keisuke; Hashimoto, Yoshikazu; Takahashi, Hajime; Balčytis, Armandas; Seniutinas, Gediminas; Okazaki, Shinji; Juodkazytė, Jurga; Iwasa, Takeshi; Taketsugu, Tetsuya; Tominaga, Yoriko; Juodkazis, Saulius

doi:10.1364/oe.25.024081

Cited by 29 publications

(32 citation statements)

References 51 publications

(52 reference statements)

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“…As a class of emerging photonic materials, noble metal alloys with permittivity and localized surface plasmon resonances not achievable by pure metals have been proposed as alternative candidates for plasmonics because of their tunable dielectric functions, which make it possible to engineer the alloy composition to attain optical properties that will meet desired resonances. In turn, this tunability could be used to improve the performance of devices for a variety of applications, such as perfect absorbers, photovoltaics, hydrogen storage, metallurgy, catalysis, and electrocatalysis . However, in contrast to the well‐investigated dispersion relation of pure noble metals (Ag and Au), the dispersion of SPPs for Ag–Au alloys has rarely been explored .…”

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confidence: 99%

Band Structure Engineering by Alloying for Photonics

Gong

Kaplan

Benson

et al. 2018

Advanced Optical Materials

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at deep sub-wavelengths, [2] leading to a variety of applications including nanolasers, [3] sensors, [4] bioimaging, [5] surfaceenhanced Raman spectroscopy, [6,7] color displays, [8] and others. [9][10][11][12] To improve the performance of today's photonic systems, researchers have extensively investigated the fundamental relation between the wave vector and energy of an SPP wave-named dispersion relation. This quantity describes the propagation of light within a material (i.e., medium), extremely relevant for the abovementioned optical devices. Therefore, understanding the dispersion relation can allow the design of optical materials with superior response, ranging from 2D van der Waals to oxides and metals. Concerning 2D materials, it can uncover the origin of tunable polaritons in hyperbolic metamaterials based on graphene and hexagonal boron nitride (h-BN), which is due to the hybridization of SPP and surface phonon polaritons. [13] As another example, by utilizing the band-edge mode of the dispersion relation in metallic nanocavities, [3] lasing with a 200 times enhancement of the spontaneous emission rate of the dye has been reached. [14] As a class of emerging photonic materials, noble metal alloys with permittivity and localized surface plasmon resonances not achievable by pure metals [9,15,16] have been proposed as alternative candidates for plasmonics [12,[17][18][19][20] because of their tunable dielectric functions, which make it possible to engineer the alloy composition to attain optical properties that will meet desired resonances. In turn, this tunability could be used to Surface plasmon polaritons (SPPs) enable the deep subwavelength confinement of an electromagnetic field, which can be used in optical devices ranging from sensors to nanoscale lasers. However, the limited number of metals that satisfy the required boundary conditions for SPP propagation in a metal/dielectric interface severely limits its occurrence in the visible range of the electromagnetic spectrum. We introduce the strategy of engineering the band structure of metallic materials by alloying. We experimentally and theoretically establish the control of the dispersion relation in Ag-Au alloys by varying the film chemical composition. Through X-ray photoelectron spectroscopy (XPS) measurements and partial density-of-states calculations we deconvolute the d band contribution of the density-of-states from the valence band spectrum, showing that the shift in energy of the d band follows the surface plasmon resonance change of the alloy. Our density functional theory calculations of the alloys band structure predict the same variation of the threshold of the interband transition, which is in very good agreement with our optical and XPS experiments. By elucidating the correlation between the optical behavior and band structure of alloys, we anticipate the fine control of the optical properties of metallic materials beyond pure metals. Band Structure EngineeringThe ORCID identification number(s) for the author(s) of this article can b...

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confidence: 99%

Band Structure Engineering by Alloying for Photonics

Gong

Kaplan

Benson

et al. 2018

Advanced Optical Materials

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“…A possible application of color change as a result of optical impedance mismatch in black metal layers can be in use for visualization of hydrogen uptake in sensors where Pd and Pd-containing alloys take up H + 2 and H + with strong lattice change of the host metal [22]. Figure A3b shows numerical simulations for cross sections where Ti metal layers are exposed to air (ambience) by triangular incisions which simulate laser ablated trenches.…”

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Black Metals: Optical Absorbers

Lundgaard

Nishijima

et al. 2020

Micromachines

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We demonstrate a concept and fabrication of lithography-free layered metal-SiO2 thin-film structures which have reduced reflectivity (black appearance), to as low as 0.9%, with 4.9% broadband reflectance (8.9% for soda lime) in the 500–1400 nm range. The multi-layered (four layers) thin-film metamaterial is designed so that optical impedance matching produces minimal reflectance and transmittance within the visible and infra-red (IR) spectral region for a range of incident angles. The structure has enhanced absorbance and is easily tuned for reduced minimal transmission and reflection. This approach should allow for novel anti-reflection surfaces by impedance matching to be realized.

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“…As the steric dimensions of molecular hydrogen ion are very small [10,19], absorption In the present study, SERS was applied to investigate the HER and HOR processes on thin Pd layer sputtered on nano-structured copper-oxide substrate. Pd was chosen due to its well known ability to absorb significant amounts of hydrogen [20]. Reversible HER and HOR reactions on Pd surface are expected to follow the same route as on Pt electrode within E range from 0 V to 0.3 V (SHE), therefore the formation of (H 3 O + ) ad and (H + 2 ) ad ions should be anticipated.…”

Section: Introduction: Thermodynamics Of Hydrogen Evolution Reactionmentioning

confidence: 99%

Hydrogen Evolution on Nano-Structured CuO/Pd Electrode: Raman Scattering Study

Juodkazytė¹,

Juodkazis²,

Matulaitienė³

et al. 2019

Preprint

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In this study the processes taking place on the surfaces of nanostructurized Cu/CuO and Cu/CuO/Pd electrodes at different potential, $E$, values in the solutions of 0.1 M KOH in H$_2$O and D$_2$O (heavy water) were probed by the surface enhanced Raman spectroscopy (SERS) and analysis of electrochemical reactions occurring under experimental conditions is presented. Bands of the SERS spectra of Cu/CuO/Pd electrode observed in the range of $E$ values from +0.3~V to 0 V~(SHE) at 1328 - 1569~cm$^{-1}$ are consistent with the existence of species which are adsorbed or weakly bound to the surface with the energy of interaction close to 15 - 21~kJ mol$^{-1}$. These bands can be attributed to the ad(ab)sorbed (H$_3$O$^+$)$\rm{_{ad}}$, (H$_2^+$)$\rm{_{ab}}$ and (H$_2^+$)$\rm{_{ad}}$ ions as intermediates in reversible HER/HOR processes taking place on Cu/CuO/Pd electrode. There was no isotopic effect observed; this is consistent with a dipole nature of electron-ion pair formation of adsorbed (H$_3$O$^+$)$\rm{_{ad}}$ and (H$_2^+$)$\rm{_{ad}}$ or (D$_3$O$^+$)$\rm{_{ad}}$ and (D$_2^+$)$\rm{_{ad}}$. In accordance with literature data SERS bands at 125-146~cm$^{-1}$ and $\sim 520-565$~cm$^{-1}$ were assigned to Cu(I) and Cu(II) oxygen species. These findings corroborate the mechanism of cascading reduction of water.

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Optical readout of hydrogen storage in films of Au and Pd

Cited by 29 publications

References 51 publications

Band Structure Engineering by Alloying for Photonics

Band Structure Engineering by Alloying for Photonics

Black Metals: Optical Absorbers

Hydrogen Evolution on Nano-Structured CuO/Pd Electrode: Raman Scattering Study

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