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Lithographically PatternedGold/Manganese DioxideCore/Shell Nanowires for High Capacity, High Rate, and High CyclabilityHybrid Electrical Energy Storage.
- Source :
-
Chemistry of Materials . Jun2012, Vol. 24 Issue 12, p2382-2390. 9p. - Publication Year :
- 2012
-
Abstract
- We describe the fabrication of arrays of nanowires onglass inwhich a gold core nanowire is encapsulated within a hemicylindricalshell of manganese dioxide. Arrays of linear gold (Au) nanowires arefirst prepared on glass using the lithographically patterned nanowireelectrodeposition (LPNE) method. These Au nanowires have a rectangularcross-section with a width and height of â200 and 40 nm, respectively,and lengths in the 1 mm to 1 cm range. Au nanowires are then usedto deposit MnO2by potentiostatic electrooxidation fromMn2늉溶⨧, forming a conformal, hemicylindrical shellwith a controllable diameter ranging from 50 to 300 nm surroundingeach Au nanowire. This MnO2shell is δ-phase andmesoporous, as revealed by X-ray diffraction and Raman spectroscopy.Transmission electron microscopy (TEM) analysis reveals that the MnO2shell is mesoporous (mp-MnO2),consisting of a network of â2 nm fibrils. The specific capacitance, Csp, of arrays of gold:mp-MnO2nanowires is measured using cyclic voltammetry.For a mp-MnO2shell thickness of 68 ±3 nm, core:shell nanowires produce a Cspof 1020 ± 100 F/g at 5 mV/s and 450 ±70 F/g at 100 mV/s. The cycle stability of this Csp, however, is extremely limited inaqueous electrolyte, decaying by >90% in 100 scans, but after ovendrying and immersion in dry 1.0 M LiClO4, acetonitrile,dramatically improved cycle stability is achieved characterized bythe absence of Cspfadefor 1000 cycles at 100 mV/s. Core:shellnanowires exhibit true hybridenergy storage, as revealed by deconvolution of Cspinto insertion and noninsertion components. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 08974756
- Volume :
- 24
- Issue :
- 12
- Database :
- Academic Search Index
- Journal :
- Chemistry of Materials
- Publication Type :
- Academic Journal
- Accession number :
- 77529198
- Full Text :
- https://doi.org/10.1021/cm3011474