Hydrogen storage and hydrolysis properties of core-shell structured Mg-MFx (M=V, Ni, La and Ce) nano-composites prepared by arc plasma method

Abstract In this work, core-shell structured Mg-MF x (M = V, Ni, La and Ce) nano-composites are prepared by using arc plasma method. The particle size distribution, phase components, microstructures, hydrogen sorption properties of these composites and hydrolysis properties of their corresponding hydrogenated powders are carefully investigated. It is shown that the addition of MF x through arc plasma method can improve both the hydrogen absorption kinetics of Mg and the hydrolysis properties of corresponding hydrogenated powders. Among them, the Mg-NiF 2 composite shows the best hydrogen absorption properties at relatively low temperatures, which can absorb 3.26 wt% of H 2 at 373 K in 2 h. Such rapid hydrogen absorption rate is mainly due to the formation of Mg 2 Ni and MgF 2 on Mg particles during arc evaporation and condensation. In contrast, measurements also show that the hydrogenated Mg-VF 3 composite has the lowest peak desorption temperature and the fastest hydrolysis rate among all the hydrogenated Mg-MF x composites. The less agglomeration tendency of Mg particles and VO 2 covered on MgH 2 particles account for the reduced hydrogen desorption temperature and enhanced hydrolysis rate.