Growth of well-aligned γ-MnO2 monocrystalline nanowires through a coordination-polymer-precursor route

A new coordination-polymer-precursor route has been developed to synthesize nanowires under hydrothermal conditions. In the present work, well-aligned gamma-MnO2 nanowires, growing along the [002] axis, have successfully been prepared by selecting an appropriate coordination polymer [{Mn(SO4)(4,4'-bpy)(H2O)(2)}(n)] as precursor. In comparison with the experimental results from other coordination-poly-mer precursors, it is found that only [{Mn(SO4)(4,4'-bpy)(H2O)(2)}(n)] is appropriate for the formation of gamma-MnO2 crystal lattices during the process of oxidization. The IR absorption spectra of as-obtained precipitates at different reaction intervals minutely describe the reaction process, due to the different coordination abilities of ligands in the coordination polymer. More evidence about the mechanism will be further explored in the future study. Further observations show the ordered alignment of nanowires' tops and such well-aligned nanowires provide more possible applications in lithium batteries.