Hierarchical MnO₂ nanosheets synthesized via electrodeposition-hydrothermal method for supercapacitor electrodes

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• 作者：Dongdong Zheng ; Yujie Qiang ; Shenying Xu ; Wenpo Li ; Shanshan Yu…
• 刊名：Applied Physics A
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：123
• 期：2
• 全文大小：
• 刊物类别：Physics and Astronomy
• 刊物主题：Condensed Matter Physics; Optical and Electronic Materials; Nanotechnology; Characterization and Evaluation of Materials; Surfaces and Interfaces, Thin Films; Operating Procedures, Materials Treatment
• 出版者：Springer Berlin Heidelberg
• ISSN：1432-0630
• 卷排序：123

文摘

Metal oxides have emerged as one kind of important supercapacitor electrode materials. Herein, we report hierarchical MnO₂ nanosheets prepared of indium tin oxide (ITO) coated glass substrates via a hybrid two-step protocol, including a cathodic electrodeposition technique and a hydrothermal process. The samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX), and transmission electron microscope (TEM). SEM and TEM images show that the as-synthesized MnO₂ nanosheets are hierarchical and porous, which could increase the active surface and short paths for fast ion diffusion. The results of nitrogen adsorption––desorption analysis indicate that the BET surface area of the MnO₂ nanosheets is 53.031 m2 g−1. Furthermore, the electrochemical properties of the MnO₂ are elucidated by cyclic voltammograms (CV), galvanostatic charge–discharge (GCD) tests, and electrochemical impedance spectroscopy (EIS) in 0.1 M Na₂SO₄ electrolyte. The electrochemical results demonstrate that the as-grown MnO₂ nanosheet exhibits an excellent specific capacitance of 335 F g−1 at 0.5 A g−1 when it is applied as a potential electrode material for an electrochemical supercapacitor. Additionally, the MnO₂ nanosheet electrode also presents high rate capability and good cycling stability with 91.8% retention after 1000 cycles. These excellent properties indicate that the hierarchical MnO₂ nanosheets are a potential electrode material for electrochemical supercapacitors.