Sarac, BaranIvanov, Yurii P.Karazehir, TolgaMühlbacher, MarleneKaynak, BarisGreer, A. LindsaySarac, A. Sezai2025-01-062025-01-0620192051-634710.1039/c9mh00316a2-s2.0-85070634748https://doi.org/10.1039/c9mh00316ahttps://hdl.handle.net/20.500.14669/1504Pd-Based amorphous alloys can be used for hydrogen energy-related applications owing to their excellent sorption capacities. In this study, the sorption behaviour of dc magnetron-sputtered and chronoamperometrically-saturated Pd-Si-Cu metallic-glass (MG) nanofilms is investigated by means of aberration-corrected high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy, and electrochemical techniques. The volume expansion of ?V = 10.09 Å3 of a palladium hydride unit cell obtained from HRTEM images due to the hydrogenation of the Pd-MG nanofilms is 1.65 times larger than ?V of the Pd-polycrystalline counterpart loaded under the same conditions. Determined by scanning transmission electron microscopy-high annular dark-field imaging and electron energy loss spectroscopy, the huge difference between the two Pd-based systems is accounted for by the "nanobubbles" originating from hydrogenation, which generate active sites for the formation and expansion of spatially dispersed palladium hydride nanocrystals. A remarkable difference in the hydrogen sorption capacity is measured by electrochemical impedance spectroscopy compared to the Pd polycrystal nanofilms particularly in the ? and ? regions, where the maximum hydrogen to palladium ratio obtained from a combination of chronoamperometry and cyclic voltammetry is 1.56 and 0.61 for the MG and Pd-polycrystal nanofilms, respectively. The findings place Pd-MGs among suitable material candidates for future energy systems. © The Royal Society of Chemistry.eninfo:eu-repo/semantics/openAccessAmorphous alloysChronoamperometryCyclic voltammetryElectrochemical impedance spectroscopyElectron energy levelsElectron energy loss spectroscopyElectron scatteringEnergy dissipationExpansionGlassHigh resolution transmission electron microscopyHydridesHydrogenationMetallic glassPalladium alloysPolycrystalsScanning electron microscopySorptionX ray photoelectron spectroscopyAberration-correctedAnnular dark-field imagingElectrochemical techniquesHydrogen sorption capacityMaterial candidatePalladium hydrideScanning transmission electron microscopySorption capacitiesPalladium compoundsArticle14877Q114816