Enhancement of Interfacial Hydrogen Interactions with Nanoporous Gold-Containing Metallic Glass

Baran Sarac, Yurii P. Ivanov, Matej Micusik, Tolga Karazehir, Barbara Putz, Sylvain Dancette, Maria Omastova, A. Lindsay Greer, A. Sezai Sarac, Jürgen Eckert

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Contrary to the electrochemical energy storage in Pd nanofilms challenged by diffusion limitations, extensive metal–hydrogen interactions in Pd-based metallic glasses result from their grain-free structure and presence of free volume. This contribution investigates the kinetics of hydrogen–metal interactions in gold-containing Pd-based metallic glass (MG) and crystalline Pd nanofilms for two different pore architectures and nonporous substrates. Fully amorphous MGs obtained by physical vapor deposition (PVD) co-sputtering are electrochemically hydrogenated by chronoamperometry. High-resolution (scanning) transmission electron microscopy and corresponding energy-dispersive X-ray analysis after hydrogenation corroborate the existence of several nanometer-sized crystals homogeneously dispersed throughout the matrix. These nanocrystals are induced by PdHx formation, which was confirmed by depth-resolved X-ray photoelectron spectroscopy, indicating an oxide-free inner layer of the nanofilm. With a larger pore diameter and spacing in the substrate (Pore40), the MG attains a frequency-independent impedance at low frequencies (∼500 Hz) with very high Bode magnitude stability accounting for enhanced ionic diffusion. On the contrary, on a substrate with a smaller pore diameter and spacing (Pore25), the MG shows a larger low-frequency (0.1 Hz) capacitance, linked to enhanced ionic transfer in the near-DC region. Hence, the nanoporosity of amorphous and crystalline metallic materials can be systematically adjusted depending on AC- and DC-type applications.
Original languageEnglish
Pages (from-to)42613-42623
Number of pages11
JournalACS Applied Materials and Interfaces
Issue number36
Publication statusPublished - 15 Sept 2021

Bibliographical note

Publisher Copyright: © 2021 American Chemical Society


  • electrochemical hydrogen
  • equivalent circuit model
  • gold
  • metallic glass
  • palladium
  • thin films
  • transmission electron microscopy
  • X-ray photoelectron spectroscopy

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