We use X-ray absorption fine structure (XAFS) spectroscopy at the Si K-edge and the AgL3,2-edge to monitor the surface chemistry of silicon nanowires. We found that Si nanowiresprepared by laser ablation and thermal evaporation are coated with a thick layer of oxidesthat can be readily removed with a HF solution. HF-refreshed silicon nanowires become amoderate reducing agent and can be used as a nanostructure template upon which silvernanoaggregate deposited reductively from a Ag+ aqueous solution, reoxidizing the surfacein the process. These results are compared with those of porous silicon.
