Template-Free Preparation of Crystalline Ge Nanowire Film Electrodes via an Electrochemical Liquid鈥揕iquid鈥揝olid Process in Water at Ambient Pressure and Temperature for Energy Storage
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- 作者：Junsi Gu ; Sean M. Collins ; Azhar I. Carim ; Xiaoguang Hao ; Bart M. Bartlett ; Stephen Maldonado
- 刊名：Nano Letters
- 出版年：2012
- 出版时间：September 12, 2012
- 年：2012
- 卷：12
- 期：9
- 页码：4617-4623
- 全文大小：390K
- 年卷期：v.12,no.9(September 12, 2012)
- ISSN：1530-6992
文摘
The direct electrodeposition of crystalline germanium (Ge) nanowire film electrodes from an aqueous solution of dissolved GeO2 using discrete 鈥榝lux鈥?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+ battery anodes. Cycling studies performed at 1 C (1624 mA g鈥?) indicated the native Ge nanowire films supported stable discharge capacities at the level of 973 mA h g鈥?, higher than analogous Ge nanowire film electrodes prepared through an energy-intensive vapor鈥搇iquid鈥搒olid 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.