Shape-Controlled Synthesis of One-Dimensional MnO2 via a Facile Quick-Precipitation Procedure and its Electrochemical Properties

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• 作者：Sheng Chen ; Junwu Zhu ; Qiaofeng Han ; Zhijun Zheng ; Yong Yang ; Xin Wang
• 刊名：Crystal Growth & Design
• 出版年：2009
• 出版时间：October 7, 2009
• 年：2009
• 卷：9
• 期：10
• 页码：4356-4361
• 全文大小：974K
• 年卷期：v.9,no.10(October 7, 2009)
• ISSN：1528-7505

文摘

MnO₂ with different crystallographic forms (α, γ) and morphologies (needles, rods, and spindles) was fabricated via a facile quick-precipitation procedure at a low temperature (about 83 °C) without using any templates or surfactants. The proposed mechanism is focused on the different reaction parameters that affect the behaviors of MnO₆ octahedron units (basic structural framework of MnO₂), which then exert an influence on the formation and stack of nuclei in the crystal growth process. Specific capacitances (C_s) calculated according to the area of the cyclic voltammograms (CV) curves were 233.5, 83.1 F·g⁻¹ for the needle- and 95.5, 29.3 F·g⁻¹ for the spindle-like products at the scan rate of 5, 100 mV·s⁻¹, respectively. The C_s of needle-like samples calculated by discharge curves at the current density of 2 mA·cm² is 209.8 F·g⁻¹, close to the value calculated by CV curves at the scan rate of 5 mV·s⁻¹. This methodology facilitates us to synthesize MnO₂ with discrepant one-dimensional (1D) nanostructures via a quick, simple, and mild route and may be readily extended to the preparation of many other oxide nanoparticles.