Pd nanocubes are constrained by rGO sheets to significantly change the hydrogen sorption behaviour, while showing a size dependence.

Exploiting the entropy of fusion among thermogalvanic devices and the associated configurational entropy change of bulk alkali metal alloys enables significant boosting of the thermopower from 1.5 mV K⁻¹ to 26.1 mV K⁻¹ for Na_2+xK alloys.

Magnesium has excellent hydrogen-storage properties except low hydriding and dehydriding rates. In the present work, titanium (Ti) was chosen as an additive to increase the hydriding rate of Mg and the dehydriding rate of MgH2. 15 wt.% Ti was added to MgH2 by milling in hydrogen (reactive mechanical grinding). The hydriding and dehydriding features of the Ti-added MgH2 composite (named 85 MgH2 + 15 Ti) were investigated. At the first cycle (n = 1), 85 MgH2 + 15 Ti absorbed 2.96 wt.% H for 2.5 min and 5.51 wt.% H for 60 min at 593 K in 12 bar H2, having an effective hydrogen-storage capacity of 5.51 wt.%. β-MgH2, γ-MgH2, TiH1.924, MgO, and MgTi2O4 were formed during reactive mechanical grinding. Reactive mechanical grinding of MgH2 with Ti is believed to create imperfections, produce cracks and clean surfaces, and decrease particle sizes. The phases formed during reactive mechanical grinding and their pulverization during reactive mechanical grinding are believed to make these effects stronger. Since the γ-MgH2 phase is believed to be decomposed at n = 1, the existence of the γ-MgH2 phase in the milled sample does not contribute to the improvement of the sorption behavior of Mg.

Magnesium (Mg) has good hydrogen storage features except for its slow reaction kinetics with hydrogen and high hydride decomposition temperature. Yttria (Y₂O₃)-stabilized zirconia (ZrO₂) (YSZ), nickel (Ni), and graphene were picked as additives to Mg to solve these problems. Samples with a composition of 92.5 wt% Mg + 2.5 wt% YSZ + 2.5 wt% Ni + 2.5 wt% graphene (designated as Mg + YSZ + Ni + graphene) were prepared by grinding in hydrogen atmosphere. The activation of Mg + YSZ + Ni + graphene was finished at the third cycle (n = 3). Mg + YSZ + Ni + graphene had an efficient hydrogen storage capacity (the amount of hydrogen absorbed for 60 min) over 7 wt% (7.11 wt%) at n = 1. Mg + YSZ + Ni + graphene contained Mg₂Ni phase after cycling. The addition of Ni and Ni + YSZ greatly increased the initial hydride formation and decomposition rates, and the amount of hydrogen absorbed and released for 60 min, H_a (60 min) and H_d (60 min), respectively, of a 95 wt% Mg + 5 wt% graphene sample (Mg + graphene). Rapid nucleation of the Mg₂Ni-H solid solution in Ni-containing samples is believed to have led to higher initial decomposition rates than Mg + graphene and Mg. The addition of YSZ also enhanced the initial decomposition rate and H_d (60 min) compared to a sample with a composition of 95 wt% Mg + 2.5 wt% Ni + 2.5 wt% graphene (Mg + Ni + graphene).