Enhancement Mechanism of Electrochemical Capacitance in Nitrogen-/Boron-Doped Carbons with Uniform Straight Nanochannels
Enhancement Mechanism of Electrochemical Capacitance in Nitrogen-/Boron-Doped Carbons with Uniform Straight Nanochannels
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DOI：
10.1021/la901318d
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发表时间：
2009-10-06
期刊：
影响因子：
3.9
通讯作者：
Kyotani, Takashi
中科院分区：
文献类型：
--
作者：
Kwon, Taeri;Nishihara, Hirotomo;Kyotani, Takashi
具有均匀直纳米通道的阳极氧化铝（AAO）完全被纯碳层、N掺杂碳层或B掺杂碳层覆盖。在水性（1 M硫酸）和有机（1 M Et（4）NBF（4）s/聚碳酸亚丙酯）电解质溶液中测量它们的双电层电容，以研究由N-或B-掺杂引起的电容增强机制。由于三种类型的碳包覆的AAO（纯的、N掺杂的或B掺杂的）具有完全相同的孔结构，所观察到的电容增强仅归因于以下因素：（i）更好的润湿性，（ii）等效串联电阻的降低，（iii）空间电荷层电容的贡献，以及（iv）赝电容的发生。从测量的润湿性和电阻的涂层AAOs连同电化学调查（循环伏安法，恒电流充电/放电循环，和阻抗分析），它的结论是，通过法拉第电荷转移（因子iv）的赝电容是最重要的因素，以提高瓷砖电容由N-或B-掺杂。这不仅可以应用于本发明的碳涂覆的AAO，而且可以应用于任何其它多孔碳。
Anodic aluminum oxide (AAO) with uniform straight nanochannels was completely coated with pure, N-doped, or B-doped carbon layer. Their electric double layer capacitances are measured in aqueous (I M sulfuric acid) and organic (1 M Et(4)NBF(4)s/polypropylene carbonate) electrolyte solutions in order to investigate the capacitance enhancement mechanisms caused by N- or B-doping. Since the three types of carbon-coated AAOs (pure, N-doped, or B-doped) have exactly the same pore structure, the observed capacitance enhancement was ascribable to only the following factors: (i) better wettability, (ii) the decrease of equivalent series resistance, (iii) the contribution of space-charge-layer capacitance, and (iv) the occurrence of pseudocapacitance. From the measurements of the wettability and the electrical resistance of the coated AAOs together with the electrochemical investigation (the cyclic voltammetry, the galvanostatic charge/discharge cycling, and the impedance analysis), it is concluded that the pseudocapacitance through faradic charge transfer (factor iv) is the most important factor to enhance tile capacitance by N- or B-doping. This can be applied to not only the present carbon-coated AAOs but also any other porous carbons.