Abstract

Magnesium hydride, a promising candidate for hydrogen storage applications, boasts a high hydrogen storage capacity and relatively low cost. Generally, its practical application was limited by the high dehydrogenation temperature, sluggish kinetics, and rapid capacity decay. In this paper, MXene Ti₃C₂@NiO was successfully synthesized via etching, hydrothermal, and ultrasonic methods and then employed as a catalyst to enhance the hydrogen storage performance of MgH₂. The composite exhibited a lower dehydrogenation temperature (The initial dehydrogenation temperature is 183.5 oC), faster hydrogen de/absorption rates, and better cycling stability. Moreover, the composite achieved a dehydrogenation capacity of 6.52?wt% H₂ within 4?min at 300 oC, significantly enhancing the hydrogen de/absorption kinetics of MgH₂. Synthesizing the characterization tests, it could be found that the in-situ generated metallic Ti, which, in synergy with Mg₂Ni/Mg₂NiH₄, promoted hydrogen adsorption and dissociation. This conclusion might provide a new design insight for improving the hydrogen storage kinetics of Mg-based materials with highly active catalysts.