Mesoporous polyhedral cages and shells formed by textured self-assembly of ZnO nanocrystals.

We report a new structure, mesoporous structured polyhedral drum and spherical cages and shells formed by textured self-assembly of ZnO nanocrystals, which are made by a novel self-assembly process during epitaxial surface oxidation. The cages/shells exhibit unique geometrical shapes, and their walls are composed of mesoporous and textured ZnO nanocrystals. The structures of the cages and shells are studied, and a growth mechanism is proposed to be a process following solidification of the Zn liquid droplets, surface oxidation, and sublimation.