Hierarchical 3D ZnO nanowire structures via fast anodization of zinc

Abstract

ZnO nanowire structures are used today in a variety of applications, from gas/chemical sensing to photocatalysis, photovoltaics and piezoelectric actuation. Electrochemical anodization of zinc foil allows rapid formation of high aspect ratio ZnO nanowires under mild reaction conditions compared to more common fabrication methods. In this study we demonstrate, for the first time, how 3D hierarchical ZnO nanowire structures can be fabricated by controlling the type of electrolyte and anodization voltage, temperature and time. Optimization of the reaction conditions yields growth rates of up to 3.2 μm min -1 and the controlled formation of aligned arrays of nanowires, flower-like nanostructures, and hierarchical, fractal nanowire structures. Annealing of the nanowires produces high surface area (55 m 2 g -1 ) nanowires with slit-type pores perpendicular to the nanowire axis. In depth analysis of the anodization process allows us to propose the likely growth mechanisms at work during anodization. The findings presented here not only contribute to our knowledge of the interesting area of zinc anodization, but also enable researchers to design complex hierarchical structures for use in areas such as photovoltaics, photocatalysis and sensing.

Recent Developments and Perspectives for Memristive Devices Based on Metal Oxide Nanowires

“…[80][81][82][83] The second category of bottom-up approaches for deposition of metal oxide NWs relates to solution phase growth techniques. [91,92] A slightly different approach, named electrophoretic deposition, was also reported as template-assisted process. Moreover, processes are typically repeatable and compatible with CMOS technology.…”

Hierarchical growth of TiO2 nanosheets on anodic ZnO nanowires for high efficiency dye-sensitized solar cells

“…ZnO nanowires (ZNW) were produced by the electrochemical anodization of zinc foil, full details of which have been previously published [32,33]. Prior to anodization, zinc foils were annealed at 300 C for 1 h in air followed by degreasing with acetone in an ultrasonic bath for 10 min.…”

“…The ZnO nanowires (ZNW) were synthesized using an electrochemical anodization technique followed by annealing in air, full details of which can be found in a previous publication [32]. After synthesis, the nanowires were removed from the zinc substrate they were grown on and sonicated to fragment the nanowires into sections with lengths typically between 1 and 10 mm.…”

“…The polycrystalline ZnO core is produced via the rapid electrochemical anodization of zinc foil and can be modified with TiO 2 nanosheets through a simple solvothermal growth method [31,32]. The synthesis based on electrochemical anodization is a simple and time-saving process compared to the combined process of electrospinning and calcination, which was used for the synthesis of SnO 2 nanotubes [31].…”

Interaction of 3D mesostructures composed of Pd-Ni alloy nanowires with low-temperature oxygen plasma

“…Also, 3D hierarchical ZnO nanowire structures that are of interest for a variety of applications have been fabricated by means of electrochemical anodization of zinc foil [6]. Hierarchical composite nanostructures containing conductive and robust 3D skeleton composed of metallic nanowires, which are coated with a metal-oxide semiconducting layer, are promising multipurpose material for applications.…”