An Electrochemical Bottom-up Approach To Producing Nanostructured Electrodes Based On Nanocolumnar Zno Acting As A Self-assembled Template

摘要

An Fe_3O_4/Cu nanostructured prototype electrode was developed from a 100% bottom-up approach thanks to an original three-step electrodeposition procedure that enlists 1) the growth of a ZnO nanocolumnar template, 2) the filling of the template voids by copper prior to the dissolution of the zincite nanopillars, and 3) the plating on the remaining copper nanodots of the Fe_3O_4 phase. The key technological point is that ZnO readily forms nanorod arrays by self-assembly when an aqueous solution of Zn~(Ⅱ), saturated by dioxygen, is cathodically polarized. The as-obtained inorganic solid template is sufficiently stable for further deposition steps of any kind (metals, oxides, polymers, and so on) but is easy to remove in both acidic and alkaline media. The self-supported Fe_3O_4/Cu nanostructured electrode shows, besides sustained capacity retention, outstanding rate capability when electrochemically tested versus Li. This original and soft process, derived from template-assisted synthesis, avoids fixing (mechanically) a nanoporous membrane on the substrate, thus, enabling nanostructural design on shapeless surfaces.