Electrochemically prepared porous silver and its application in surface-enhanced Raman scattering

We have demonstrated for the first time that silver can be electrochemically etched to form porous structures ranging from the nano- to the microscale. Silver wires, foils and films deposited on a silicon wafer were etched in both acidic (HF) and basic (NH3) N,N-dimethylformamide (DMF) solutions. We describe a possible etching mechanism for pore formation in which the convection within the etching solution focuses the etching current, while the organic solvent component stabilizes the nascent pore walls. Finally, the fabricated porous silver was shown to act as an effective substrate for surface-enhanced Raman scattering (SERS).