Electropolymerized Polyaniline Stabilized Tungsten Oxide Nanocomposite Films: Electrochromic Behavior and Electrochemical Energy Storage

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• 作者：Huige Wei ; Xingru Yan ; Shijie Wu ; Zhiping Luo ; Suying Wei ; Zhanhu Guo
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：November 29, 2012
• 年：2012
• 卷：116
• 期：47
• 页码：25052-25064
• 全文大小：860K
• 年卷期：v.116,no.47(November 29, 2012)
• ISSN：1932-7455

文摘

Polyaniline (PANI)/tungsten oxide (WO₃) nanocomposite films were fabricated by electropolymerization of aniline monomers onto WO₃ coated indium tin oxide (ITO) glass slides, which were prepared by spin coating technique and followed by annealing at 500 掳C for 2 h. The morphology and crystalline structure of the composite films were studied using Fourier transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results confirm chemical interactions between the polymer matrix and the WO₃ particles and reveal a well crystallized PANI/WO₃ nanocomposite structure. The optical properties and electrochemical capacitive behaviors of the composite films for electrochromic (EC) and energy storage devices applications were investigated using spectroelectrochemistry (SEC), cyclic voltammetry (CV) and galvanostatic charge鈥揹ischarge measurements. The composite films show dual electrochromism at both positive and negative potentials arising from PANI and WO₃, respectively. A coloration efficiency of 98.4 cm² C^鈥? was obtained for the composite film, which was much higher than that of WO₃ (36.3 cm² C^鈥?) and PANI (50.0 cm² C^鈥?) thin film. An areal capacitance of 0.025 F cm^鈥? that is comparable to that of pure PANI (0.075 F cm^鈥?) is derived from CV at a scan rate of 5 mV/s with a broader working potential window of 1.3 V. The cyclic stability studies reveal that the composite films exhibit much more enhanced durability and retain significant charge storage or discharge capacity after 1000 charge鈥揹ischarge cycles. However, pure PANI loses most of the charge storage or discharge capacity after 350 cycles. The chemical bonding between PANI matrix and WO₃ particles is believed to play an important role in enhancing the stability of the nanocomposite film.