Figure 10.

SEM and TEM characterizations of spindle-like Co3O4 porous and hollow nanocapsules: a low-magnification SEM image exhibiting that these spindle-like nanocapsules have porous shell; b low-magnification TEM image showing a single porous Co3O4 nanocapsule; c high-magnification TEM image indicates that the porous shell consists of a great deal of Co3O4 nanocrystals in the size of ~20 nm. The inset is the SAED pattern taken from a single nanocapsule, indicating that these porous nanocapsules are polycrystalline; d HRTEM image of Co3O4 nanocrystals revealing the (111) lattice plane

Liu and Xue Nanoscale Research Letters 2010 5:1525-1534   doi:10.1007/s11671-010-9728-5