Two-dimensional vanadium nanosheets as a remarkably effective catalyst for hydrogen storage in MgH2

Magnesium hydride (MgH 2 ), which possesses high hydrogen density of 7.6 wt%, abundant resource and non-toxicity, has captured intense attention as one of the potential hydrogen storage materials. However, the practical application of Mg/MgH 2 system is suffering from high thermal stability, sluggish absorption and desorption kinetics. Herein, two-dimensional (2D) vanadium nanosheets (V NS ) were successfully prepared via a facile wet chemical ball milling method and proved to be highly effective on improving the hydrogen storage performance of MgH 2 . For instance, the MgH 2  + 7 wt% V NS composite began to release hydrogen at 187.2 °C, 152 °C lower than that of additive-free MgH 2 . At 300 °C, 6.3 wt% hydrogen was released from the MgH 2  + 7 wt% V NS composite within 10 min. In addition, the fully dehydrogenated sample could absorb hydrogen even at room temperature under hydrogen pressure of 3.2 MPa. X-ray diffractometer (XRD) and transmission electron microscopy (TEM) results confirmed metallic vanadium served as catalytic unit for facilitating the de/rehydrogenation reaction of MgH 2 . This finding presents an example of facile synthesis of two-dimensional (2D) vanadium with excellent catalysis, which may shed light on future design and preparation of highly effective layered catalysts for hydrogen storage and other energy-related areas.