Hydrogen-rich materials are paving the way for breakthroughs in superconductivity, but the path to efficiently incorporating hydrogen into these materials has been fraught with challenges. Our recent study, published in the Journal of Molecular Liquids, unveils a transformative method for hydrogen loading using deep eutectic solvents (DES), which promises to revolutionise this field.
Led by a collaborative team of researchers from Politecnico di Torino, the Ca’ Foscari University of Venice and other institutions, the study demonstrates how a simple mixture of choline chloride and glycerol can replace the traditionally used ionic liquids for hydrogen incorporation. This innovative approach addresses key issues such as cost, toxicity, and environmental impact while achieving hydrogen concentrations high enough to induce superconductivity in palladium.
The concept hinges on ionic gating-induced protonation (IGP), a technique that uses an electric field to drive hydrogen ions into materials. By leveraging the unique properties of DES—low viscosity, biodegradability, and cost-effectiveness—the researchers successfully injected hydrogen into palladium bulk foils and thin films, achieving a stoichiometry of up to PdH₀.₈₉. While partial superconducting transitions were observed in thin films, the study underscores the need for further refinement to ensure a uniform hydrogen distribution within materials.
Beyond Palladium: A Vision for the Future
Though the research focuses on palladium as a model system, its implications extend far beyond. The DES-based IGP method could be adapted for a wide range of materials, offering promising applications in hydrogen storage, spintronics, and quantum technologies. This breakthrough aligns with global efforts to develop more sustainable and accessible superconducting technologies at practical pressures and temperatures.
This groundbreaking study represents a significant leap forward in material science, potentially heralding a new era of innovation. For more details, you can access the full article in the Journal of Molecular Liquids: https://doi.org/10.1016/j.molliq.2024.126826.