6 research outputs found
Template-Free Preparation of Crystalline Ge Nanowire Film Electrodes via an Electrochemical Liquid–Liquid–Solid Process in Water at Ambient Pressure and Temperature for Energy Storage
The direct electrodeposition of crystalline germanium
(Ge) nanowire
film electrodes from an aqueous solution of dissolved GeO<sub>2</sub> using discrete ‘flux’ nanoparticles capable of dissolving
Ge(s) has been demonstrated. Electrodeposition of Ge at inert electrode
substrates decorated with small (<100 nm), discrete indium (In)
nanoparticles resulted in crystalline Ge nanowire films with definable
nanowire diameters and densities without the need for a physical or
chemical template. The Ge nanowires exhibited strong polycrystalline
character as-deposited, with approximate crystallite dimensions of
20 nm and a mixed orientation of the crystallites along the length
of the nanowire. Energy dispersive spectroscopic elemental mapping
of individual Ge nanowires showed that the In nanoparticles remained
at the base of each nanowire, indicating good electrical communication
between the Ge nanowire and the underlying conductive support. As-deposited
Ge nanowire films prepared on Cu supports were used without further
processing as Li<sup>+</sup> battery anodes. Cycling studies performed
at 1 C (1624 mA g<sup>–1</sup>) indicated the native Ge nanowire
films supported stable discharge capacities at the level of 973 mA
h g<sup>–1</sup>, higher than analogous Ge nanowire film electrodes
prepared through an energy-intensive vapor–liquid–solid
nanowire growth process. The cumulative data show that ec-LLS is a
viable method for directly preparing a functional, high-activity nanomaterials-based
device component. The work presented here is a step toward the realization
of simple processes that make fully functional energy conversion/storage
technologies based on crystalline inorganic semiconductors entirely
through benchtop, aqueous chemistry and electrochemistry without time-
or energy-intensive process steps