Preparation of spherical clusters of metal oxide nanorods and their hydrogen storage behavior

Spherical clusters of transition-metal oxide nanorods were prepared by using a simple, rapid and easily scaled up method, i.e. chemical precipitation followed by thermal decomposition. The microstructural characteristics of spherical clusters of nanorods were examined by scanning electron microscopy (SEM). It was found that the nanorods were displayed on the surfaces of the spherical particles that had grown from the center of the spherical particles to their surface. It is worth pointing out that the spherical clusters of nanocrystals could serve as effective confined templates for spherical nanostructures. Hydrogen adsorption/desorption experiments were carried out at room temperature. A hydrogen storage capacity of 0.71% was achieved under a pressure of 3.05 MPa for spherical clusters of doped NiO nanorods with a surface area of 113.39 m2/g, and about 66.8% of the stored hydrogen could be released under ambient pressure. © 2006 Elsevier B.V. All rights reserved.