A novel oxidation-resistible Mg@Ni foam material for safe, efficient, and controllable hydrogen generation

As a promising in-situ hydrogen generation material, magnesium (Mg) has been seeking a promotion in its hydrogen generation property. Increasing the specific surface area, for example, replacing the Mg bulk using Mg powder, can greatly increase the hydrogen generation property, but it brings a high explosion risk, a difficulty in controlling the hydrogen generation, and an oxidation problem. In this work, we prepare a novel Mg@Ni foam material with Mg deposits on Ni foam by a physical vapor deposition method. The Ni foam not only increases the hydrolysis reaction areas of Mg by improving its specific surface area, but also kinetically accelerates the hydrolysis reaction rate of Mg by forming a uniform Mg-Ni galvanic cell. As a result, the Mg@Ni foam material realizes a near-theoretical hydrogen generation amount of Mg and a hydrogen generation rate significantly higher than those realized by the bulk Mg-based materials. The Mg@Ni foam material with the excellent hydrogen generation property is also free from explosion risk, easy to be controlled, and resistible to oxidation. A hydrogen fuel cell powered by the hydrogen generated by the Mg@Ni foam material can yield a steady voltage and run a small car for a long distance.