Two‐dimensional vanadium nanosheets as a remarkably effective catalyst for hydrogen storage in MgH ₂

Abstract 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.

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