Scrolled Sheet Precursor Route to Niobium and Tantalum Oxide Nanotubes

Abstract

The nanoscroll-to-nanotube thermal transformation was studied for H 4 Nb 6 O 17 ·4.4H 2 O scrolls, prepared by exfoliation of K 4 Nb 6 O 17 . Thermal dehydration of the scrolls produces Nb 2 O 5 nanotubes at 400−450 °C. The nontopochemical transformation results in polycrystalline nanotubes; however, significant texturing with respect to the tube axis is observed. Substituting Ta for Nb in the precursor compound led to a lower yield of scrolls, most likely because there is less built-in lattice strain to drive scrolling of the unilamellar colloidal sheets.