Formation of silver nanorod arrays in an anodised aluminium oxide membrane

Abstract

A highly ordered silver nanorod array (AgNRs) with a diameter of 90 nm has been prepared by chemical reduction from silver nitrate in a porous anodic aluminium oxide (AAO) membrane. The AAO membrane was fabricated electrochemically in an oxalic acid solution via a one-step anodisation process, followed by the growth of silver NR in the long-range ordered nanochannels of the AAO membrane via chemical reduction. The morphologies of AAO membrane and AgNRs with periodic rows of air-pockets encapsulated in the AAO membrane have been investigated using TEM. The crystalline structure and chemical composition have been confirmed by XRD, TEM and EDX techniques. The process, which has three stages, namely, (1) anodising of aluminium foil to form a mesoporous membrane, (2) adsorption of metal ions, then (3) chemical reduction of the adsorbed metal ions to form the nanorod array of AgNRs in the pores of AAO membrane, has not, to the authors’ knowledge, been reported to date.

Keywords:

• Electron microscopy
• X-ray diffraction
• Porous materials
• Nanostructured materials
• Chemical reduction
• Nucleation
• Crystallisation

Acknowledgements

The authors acknowledge the relevant earlier classical C. A. Grimes and P. Smucki studies on anodisation of titanium metal substrates to produce nanoporous titanium oxide arrays. One of the authors, GS, wishes to thank CSIR for the award of Senior Research Fellowship. The authors also thank C. Mohan for his support during the course of the experimentation, Mr R. Ravishanker (CECRI) for SEM measurement, S. Krithika for XRD measurement and Mr A. Rathish Kumar for TEM measurements.