Synthesis of cobalt hollow spherical nanostructures using aluminum powders as reductants and templates

The core–shell Al/Co nanocomposites with sheet-like and spherical Co nanocrystals as shells were fabricated via a displacement reaction between Al and CoCl2·6H2O in a glycol solution by the controlling feeding rate of NH4F glycol solution. By eroding the Al core in HCl aquatic solution, hollow spherical nanostructures assembled by sheet-like and spherical Co nanocrystals were obtained. The possible mechanism for the formation of Co hollow nanostructures composed of different shaped nanocrystals has been discussed.