External electric field driven 3D ordering architecture of silver (I) oxide meso-superstructures

We report an external electric field driven particle-mediated bottom-up assembling methodology to in situ build the Ag2O meso-superstructures with controlled shape and size within an electrochemical deposition system. Different shapes (rhombic hexahedron, cube and dodecahedron) and sizes (around 100 to similar to 800 nm) of Ag2O mesocrystals have been obtained by the adjustment of the applied overpotential as well as the growth time. Various overpotentials play a crucial role in determining the shapes, structures as well as growth modes of the final product. The growth mechanism of polyhedral structures of Ag2O meso-superstructures is explained by the oriented attachment from the nature of crystallographic surfaces and the external electric induced ordering alignment process of primary nanoparticle building blocks. Thus, the current strategy not only provides the direct evidence of an external electric field driving in situ mesoassembling process, but also may be extended to other systems to synthesize the mesa-superstructures. (C) 2010 Elsevier Ltd. All rights reserved.