Surface reactivity of Si nanowires

The chemical reactivity of hydrogen-passivated surface of silicon nanowires (SiNWs) towards the reductive deposition of silver and copper ions from solution is reported. SiNWs synthesized by laser ablation were used in the investigation. The surface properties of SiNWs after the removal of the surface oxide were studied. It is found that the surface silicon of the SiNWs can readily reduce silver (I) and copper (II) ions to metal aggregates of various morphologies on the SiNW surface at room temperature. The reaction products have been characterized with scanning electron microscopy, energy dispersive x-ray spectroscopy, high-resolution transmission electron microscopy, electron energy loss spectroscopy, and x-ray photoelectron spectroscopy. By varying the concentration of Ag(I) ions in the solution, nanostructures of silver with different shapes and sizes can be obtained. This approach for synthesis of metal nanostructures offers a potential method for the preparation of desired metal catalysts. (C) 2001 American Institute of Physics.