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

Metal alloys such as Mg2Ni and TiFe can absorb and store H2 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 Mg2Ni and Mg-Ni2 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.

► 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. ► Mg2Ni identified by XRD in sample of as-prepared Mg-Ni/C suspension. ► Superparamagnetism found in calcined Mg-Ni/C powder.