Synthesis of silver dendritic hierarchical structures and transformation into silver nanobelts through an ultrasonic process

Silver dendritic hierarchical structures have been synthesized simply by carrying out the silver mirror reaction on the surface of a porous anodic aluminium oxide (AAO) template in a surfactant-free system. The length of the stem is several tens of micrometres, and that of each leaf ranges from 0.5 to 4 mu m with a width of 100-300 nm. Our studies indicate that the growth mechanism of silver dendritic hierarchical structures is a diffusion-limited preferential growth of oriented attachment of silver nanocrystals. Also, the surface of the AAO template has a guiding effect in the formation process of the silver dendritic hierarchical nanostructure. We have observed the transformation from sliver dendritic hierarchical structures to silver nanobelts under ultrasonic treatment. This transformation is due to the dissociation of silver dendritic hierarchical structures covering over the Ag nanobelts under ultrasonic treatment.