Effects of SiC nanoparticles with and without Ni on the hydrogen storage properties of MgH2

In this work, MgH2–SiC–Ni was prepared by magneto-mechanical milling in hydrogen atmosphere. Scanning electron microscope mapping images showed a homogeneous dispersion of both Ni and SiC among MgH2 particles. Based on the differential scanning calorimetry traces, the temperature of desorption is reduced by doping MgH2 with SiC and Ni. Hydrogen absorption/desorption behaviour of the samples was investigated by Sievert's method at 300 °C, and the results showed that both capacity and kinetics were improved by adding SiC and Ni. The hydrogen desorption kinetic investigation indicated that for pure MgH2, the rate-determining step is surface controlled and recombination, while for the MgH2–SiC–Ni sample it is controlled as described by the Johnson–Mehl–Avrami 3D model (JMA 3D).