General and simple route to micro/nanostructured hollow-sphere arrays based on electrophoresis of colloids induced by laser ablation in liquid.

A general and simple route was presented to fabricate hollow sphere arrays (HSAs) with hierarchical micro/nanostructure based on electrophoresis on a polystyrene colloidal monolayer in a corresponding colloidal solution prepared by laser ablation in liquid. Si was chosen as a model material to demonstrate the validity of the route. The size and structure of such-prepared hollow spheres can be easily controlled by the size of the polystyrene spheres, the electrophoresis parameters, and the morphology of the colloidal nanoparticles. Further experiments have revealed that this strategy can be extended to produce other semiconductors' and metals' compact or noncompact HSAs, and even multicomponent HSAs with controllable spacings between adjacent spheres and tunable size of nanoparticles in the shell layers. This study could be important to synthesize some key materials in the fields of ion batteries, surface enhanced Raman scattering, new micro/nanostructured devices, and so on.