Dr. Fukami and his research group at Kyoto University have recently developed a method to prepare metal nanostructures, such as nanoparticles and nanofibers, by electrodeposition in chemically-modified porous silicon electrodes. Porous silicon with several nanometers in diameter has very large surface area and high porosity. Therefore it has attracted attentions for the utilization as a template for metal electrodeposition. However, the oxidation of silicon, which induces the uncontrollable displacement deposition, always takes place in aqueous deposition baths.
Dr. Fukami and his colleagues modified the porous silicon by organic molecules. In addition, they found that the organic molecules modified on the porous silicon wall must be hydrophobic, otherwise metal electrodeposition does not proceed within the template. For instance, they succeeded in the formation of dispersed platinum nanoparticles supported within porous silicon matrix, as shown in the following figure.