Synthesis of Magnesium Nanofibers by Electroless Reduction and their Hydrogen Interaction Properties

Magnesium (Mg) is successfully synthesized from the direct reduction of dibutylmagnesium (MgBu₂) with calcium (Ca). By adding 1‐dodecanethiol, the morphology of the magnesium particles is controlled and magnesium nanofibers with a length of 0.4–4 µm and a width of 40 nm are obtained. Besides magnesium nanofibers, isolated irregular shaped calcium particles are also observed as a by‐product of the reaction. The nanofibers readily absorbed hydrogen at 300 °C and hydrogen release occurred at much lower temperatures (360 °C) compared to the equivalent bulk material. More remarkably, these nanofibers remain stable during hydrogen cycling, but they partially react with the remaining calcium to form the ternary hydride phase Ca₁₉Mg₈H₅₄—a phase that is usually obtained at high temperatures >500 °C and hydrogen pressure 2500 MPa. Hydrogen absorption within these magnesium nanofibers shows a slightly lower enthalpy as compared to bulk magnesium. However, the hydrogen desorption properties are influenced by the presence of calcium and its reaction with magnesium.