Single-crystalline silver nanowire arrays directly synthesized onto substrates by template-assisted chemical wetting

Abstract

Silver (Ag) nanowire arrays have attracted extensive research attention for their outstanding electrochemical detection sensitivity and optical properties. The most frequently used technology for fabricating Ag nanowire arrays is electrodeposition within the pores of anodic aluminium oxide (AAO) templates. In this paper, single-crystalline Ag nanowire arrays were grown by the capillary wetting of molten Ag inside the nanopores of AAO templates at a temperature of 970 °C. To improve the infiltration height for the molten Ag in the capillaries of the AAO templates, copper oxide (CuO) was added as a supplement because it can improve the wetting behavior between molten Ag and AAO templates. After the Ag nanowire arrays were embedded within the AAO pores, a novel hydrothermal etching method was proposed to remove the AAO templates because AAO showed a phase transition, which made it difficult to remove the AAO after heating at 970 °C. To test the properties of the obtained Ag nanowire arrays, the surface-enhanced Raman scattering performance was also studied.