A cathodic electrosynthesis strategy was conceived and demonstrated for the preparation of Nb2O5 nanorods/nanotubes supported on Nb foil. This method involved an interplay of several processes including the chemical attack of fluoride species on the Nb cathode, the electrogeneration of O-2 at a proximal Pt anode, its subsequent diffusion to and electrocatalytic reduction on the Nb cathode, and finally, the chemical reaction between the ionic Nb and oxygen precursor species at the interface to generate the Nb2O5 nanoarchitectures. The oxide nanorods/nanotubes were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray analyses, and Raman spectroscopy, and their critical dimensions could be tailored via control of the growth variables. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3397507] All rights reserved.