title: A template and catalyst-free metal-etching-oxidation method to synthesize aligned oxide nanowire arrays: NiO as an example.
abstract: Although NiO is one of the canonical functional binary oxides, there has been no report so far on the effective fabrication of aligned single crystalline NiO nanowire arrays. Here we report a novel vapor-based metal-etching-oxidation method to synthesize high-quality NiO nanowire arrays with good vertical alignment and morphology control. In this method, Ni foils are used as both the substrates and the nickel source; NiCl(2) powder serves as the additional Ni source and provides Cl(2) to initiate mild etching. No template is deliberately employed; instead a nanograined NiO scale formed on the NiO foil guides the vapor infiltration and assists the self-assembled growth of NiO nanowires via a novel process comprising simultaneous Cl(2) etching and gentle oxidation. Furthermore, using CoO nanowires and Co-doped NiO as examples, we show that this general method can be employed to produce nanowires of other oxides as well as the doped counterparts.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore.
authors.forename: Zhi Peng
authors.initials: ZP
authors.lastname: Wei
authors.forename: Miryam
authors.initials: M
authors.lastname: Arredondo
authors.forename: Hai Yang
authors.initials: HY
authors.lastname: Peng
authors.forename: Zhou
authors.initials: Z
authors.lastname: Zhang
authors.forename: Dong Lai
authors.initials: DL
authors.lastname: Guo
authors.forename: Guo Zhong
authors.initials: GZ
authors.lastname: Xing
authors.forename: Yong Feng
authors.initials: YF
authors.lastname: Li
authors.forename: Lai Mun
authors.initials: LM
authors.lastname: Wong
authors.forename: Shi Jie
authors.initials: SJ
authors.lastname: Wang
authors.forename: Nagarajan
authors.initials: N
authors.lastname: Valanoor
authors.forename: Tom
authors.initials: T
authors.lastname: Wu