Core-shell structured binary Mg Ti and ternary Mg@Ti@Ni composites were synthesized using an arc plasma method followed by electroless plating in solutions. Their microstructures and hydrogen storage properties were systematically investigated. The hydrogenated composites with core shell structures containing MgH2 core and Ti or Mg-Ni hydrides shells were observed. Based on the Pressure-Composition-Temperature measurements, the hydrogen absorption enthalpy (-67.12 kJ/mol H-2) of the ternary composite was slightly higher than that of the binary composite (-77.20 kJ/mol H-2). In addition, the hydrogenation activation energy (63.7 kJ/mol H-2) of the ternary composite and the peak dehydrogenation temperature (642 K) of the hydrogenated ternary composite were also lower than those of the binary composite, respectively. These improvements in hydrogen sorption properties of Mg can be mainly attributed to the co-effect of TiH2 acting as the activation site and Mg2Ni acting as the "hydrogen pump". (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.