title: Facile formation of branched titanate nanotubes to grow a three-dimensional nanotubular network directly on a solid substrate.
abstract: The hydrothermal formation of branched titanate nanotubes that grow a 3D nanotubular network directly onto a titanium substrate is reported. The resultant 3D nanotubular network exhibits a unique all-dimensional uniform porous structure. The inner and outer tubular diameters of branched titanate nanotubes were found to be approximately 6 and 12 nm, respectively. For the majority of the nanotubes, the wall is formed from three layers of titanate with an approximate 7.7 A interlayer space. In terms of individual nanotubes, these characteristics are quantitatively similar to those of previously reported nonbranched nanotubes. However, in terms of how nanotubes are arranged in the film, the all-dimensional uniform nanotubular network structure obtained here is distinctively different from those of previously reported structures. The 3D nanotubular network structure was formed by the jointing of branched nanotubes. In contrast, the previously reported nanotubes tend to grow vertically on the substrate, and the resultant tubular films are formed by interwoven nonbranched nanotubes. The branched titanate nanotubes can be readily formed on titanium substrates but not in solution suspension forms. A continuous seed formation-oriented crystal growth mechanism was proposed for the branched titanate nanotubular network formation. Such a network structure could be useful for applications such as photocatalysis, membrane separation, field emission, and photovoltaic devices.
authors.affiliation: Environmental Futures Centre and Griffith School of Environment, Gold Coast Campus, Griffith University, QLD 4222, Australia.
authors.forename: Haimin
authors.initials: H
authors.lastname: Zhang
authors.forename: Porun
authors.initials: P
authors.lastname: Liu
authors.forename: Hongjuan
authors.initials: H
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Yu
authors.forename: Shanqing
authors.initials: S
authors.lastname: Zhang
authors.forename: Huaiyong
authors.initials: H
authors.lastname: Zhu
authors.forename: Feng
authors.initials: F
authors.lastname: Peng
authors.forename: Huijun
authors.initials: H
authors.lastname: Zhao