Solvothermal synthesis of Mg-Ni/C nanocomposite for hydrogen storage using vitamin C as carbon source

Metal alloys such as Mg 2Ni and TiFe can absorb and store H 2 to form metal hydrides. The alloys are frequently prepared by grinding the metal ingredients together. In this work, a solvothermal synthesis was taken to prepare the Mg-Ni/C nanocomposite from vitamin C, magnesium acetate, and nickel acetate, using ethylene glycol as solvent and reductant. Without adding Pd as nucleating agent, it is proposed to obtain Mg-Ni alloys by reduction and carbon nanoparticles by carbonization. XRD analysis shows that Mg 2Ni and Mg-Ni 2 have been formed as nanocomposite with carbon. After calcination in vacuum at 500 °C for 1 h, the Mg-Ni/C nanocomposite showed enhanced magnetism. XRD results give peaks of Ni and MgO, indicative of phase separation and Mg oxidation. In conclusion, it is feasible to synthesize Mg-Ni/C or other carbon-containing hydrogen storage composites using the solvothermal method. Highlights: Mg-Ni/C nanocomposite synthesized as hydrogen storage material. Polyol-assisted solvothermal synthesis used for reduction and carbonization. Vitamin C used as carbon source giving carbon-containing nanoparticles. Mg 2Ni identified by XRD in sample of as-prepared Mg-Ni/C suspension. Superparamagnetism found in calcined Mg-Ni/C powder.