Improved hydrogen storage properties of MgH2 by Mxene (Ti3C2) supported MnO2

MgH 2 is a promising high-capacity solid hydrogen storage material. In this work, MnO 2 -doped Ti 3 C 2 (Ti 3 C 2 @MnO 2 ) was synthesized and used as a catalyst to improve the hydrogen storage performance of MgH 2 . We found that the dehydrogenated 10 wt% Ti 3 C 2 @MnO 2 -doped MgH 2 sample exhibited good hydrogen adsorption ability even at room temperature (30 °C), and could absorb 5.13 wt% of hydrogen in 400 s at 75 °C. The re‑hydrogenated Ti 3 C 2 @MnO 2 -doped MgH 2 sample started to release hydrogen at 182 °C and required 484 s to completely release hydrogen at 275 °C with a dehydrogenation capacity of 6.4 wt%. The Ti 3 C 2 @MnO 2 composite did not change the thermodynamic properties of MgH 2 . In the MgH 2  + Ti 3 C 2 @MnO 2 sample, Ti 3 C 2 , TiO 2 , MnO 2 , MnO, and Mn combined with MgH 2 to form Ti 3 C 2 /MgH 2 , TiO 2 /MgH 2 , MnO 2 /MgH 2 , MnO/MgH 2 , and Mn/MgH 2 multiphase interfaces, which improved the hydrogen storage performance of MgH 2 . The findings of this work may provide a new strategy for preparing novel and efficient catalysts for hydrogen storage applications.