Improvement of desorption performance of Mg(BH4)2 by two-dimensional Ti3C2 MXene addition

Magnesium borohydride (Mg(BH 4 ) 2 ) is an attractive materials for solid-state hydrogen storage due to its high hydrogen content (14.9 wt%). In the present work, the dehydrogenation performance of Mg(BH 4 ) 2 by adding different amounts (10, 20, 40, 60 wt%) of two-dimensional layered Ti 3 C 2 MXene is studied. The Mg(BH 4 ) 2 -40 wt% Ti 3 C 2 composite releases 7.5 wt% hydrogen at 260 °C, whereas the pristine Mg(BH 4 ) 2 only releases 2.9 wt% hydrogen under identical conditions, and the onset desorption temperature decreases from 210 °C to a relative lower temperature of 82 °C. The special layered structure of Ti 3 C 2 MXene and fluorine plays an important role in dehydrogenation process especially at temperatures below 200 °C. The main dehydrogenation reaction is divided into two steps, and activation energy of the Mg(BH 4 ) 2 -40 wt% Ti 3 C 2 composite is 151.3 kJ mol −1 and 178.0 kJ mol −1 , respectively, which is much lower than that of pure Mg(BH 4 ) 2 .