Synergistic effect of TiF3@ graphene on the hydrogen storage properties of Mg–Al alloy

Abstract

Mg–Al alloy was prepared by sintering and mechanical alloying, and the effects of graphene (Gp), TiF3 and Gp/titanium (III) fluoride (TiF3) on the hydrogen storage properties of the Mg–Al alloy were studied. The results show that Gp and TiF3 could improve the hydrogen storage properties of Mg–Al alloy. In particular, Gp and TiF3 showed good synergistic effect for enhancing the hydrogen storage properties of Mg–Al alloy. For example, when 1.0 wt% of H2 was absorbed/desorbed, the hydrogen adsorption/desorption temperature of the Mg–Al alloy and Mg–Al-M (M = Gp, TiF3, and TiF3@Gp) composites were 241/343 °C, 185/310 °C, 229/292 °C and 159/280 °C, respectively. For the Mg–Al alloy, the apparent activation energy was 176.5 kJ mol−1, and it decreased to 139.8 kJ mol−1, 171.6 kJ mol−1, and 94.3 kJ mol−1, with the addition of Gp, TiF3 and TiF3@Gp composites, respectively. Evidently, the comprehensive hydrogen storage properties of Mg–Al alloy were improved remarkably under the synergistic effect of Gp and TiF3.