To investigate the concept, researchers at the University of Georgia, US, have designed and fabricated a vanadium-decorated magnesium nanoblade array structure (shown above) by coating a thin layer of vanadium onto the two sides of individual magnesium nanoblades. The structures were made using a dynamic shadowing growth (DSG) technique, which is based on a physical vapor deposition method and combines oblique angle deposition (OAD) with substrate manipulation and source control.

Test results

The catalytic role of the vanadium coating in the formation and decomposition of MgH2 and the unique nanoblade morphology with large surface area and small hydrogen diffusion length contribute to an overall improvement in hydrogen sorption performance. Specifically, the hydrogen sorption activation energy is reduced from 120–150 kJ/mol H2 for magnesium films or powders to ~35 kJ/mol H2, the hydrogen uptake and release temperatures are reduced even to room temperature, and the hydrogen loading and unloading times are reduced from 50 hours to several minutes.

The team reported its work in a special issue of Nanotechnology.