Effects of pore diameters on the pseudocapacitive property of three-dimensionally ordered macroporous manganese oxide electrodes

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• 作者：Montree Sawangphruk^a ; ^c ; ^{fengmrs@ku.ac.th} ; Jumras Limtrakul^b ; ^c
• 关键词：Pseudocapacitor ; Manganese oxide ; Polystyrene ; Colloidal template ; Supercapacitor
• 刊名：Materials Letters
• 出版年：2012
• 出版时间：1 February 2012
• 年：2012
• 卷：68
• 期：Complete
• 页码：230-233
• 全文大小：785 K

文摘

MnO₂ nanoparticles (NPs) with 1.8 ¡À 0.2 nm in diameter were successfully produced using an ethylene glycol-assisted synthesis with successive hydrolysis and condensation reactions. The tiny NPs were used as precursors for producing three-dimensionally ordered macroporous (3DOM) electrodes using a colloidal crystal-templating method. The specific capacitances of 3DOM MnO₂ electrodes depend on their pore diameters. The 3DOM electrode with about 200-nm pore diameter provides 3.0-, 2.0-, and1.3-fold higher specific capacitance than the dense film and the 3DOM electrodes with larger pores, 400 nm and 900 nm, respectively. The ultrahigh specific capacitance of the 200-nm 3DOM electrode is 765 F g^?#xA0;1 measured in 0.5 M Na₂SO₄ at the scan rate of 2 mV s^?#xA0;1. In addition, the capacity retention of the 200-nm 3DOM electrode is over 98 % of the original capacitance after 2000 cycles while that of the dense film is only 78 % .