Microstructure and hydrogen storage properties of porous Ni@Mg

A nanoporous Ni layer on the surface of Mg was prepared utilizing the reduction reaction of Ni2+ by Mg in NiCl2.12H2O solution. XRD result showed that the product was composed of cubic Ni, hexagonal Mg and little Mg(OH)2. SEM and TEM results suggested that a nanoporous Ni layer microencapsulated Mg and formed Ni@Mg. The specific surface area of Ni@Mg formed in this reaction was 65.3 m2/g. Hydrogen uptake increased as the temperature increased. Moreover, Ni@Mg showed a reversible hydriding-dehydriding process without formation of the stable hydrides, which indicated that the nanoporous Ni layer on the surface of Mg showed an obvious physisorption characteristics rather than hydrogen storage behavior of Mg.

► A nanoporous Ni layer microencapsulated Mg was prepared utilizing the reduction reaction of Ni2+ by Mg.
► The product was composed of cubic Ni, hexagonal Mg and little Mg(OH)2.
► It showed a reversible hydriding-dehydriding process without formation of stable hydrides.
► It suggested an obvious physisorption characteristic for porous Ni layer rather than hydrogen storage behavior of Mg.