Remarkable supercapacitive performance of TiO2 nanotube arrays by introduction of oxygen vacancies
Remarkable supercapacitive performance of TiO2 nanotube arrays by introduction of oxygen vacancies
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DOI：
10.1016/j.cej.2016.11.004
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发表时间：
2017-04
影响因子：
15.1
通讯作者：
Jianfang Zhang;Yan Wang;Jingjie Wu;X. Shu;Cuiping Yu;J. Cui;Yongqiang Qin;Yong Zhang;P. Ajayan-P
中科院分区：
文献类型：
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作者：
Jianfang Zhang;Yan Wang;Jingjie Wu;X. Shu;Cuiping Yu;J. Cui;Yongqiang Qin;Yong Zhang;P. Ajayan-P
高度有序的TiO 2纳米管阵列（TNAs）具有很大的比表面积，具有优异的电化学性能，但其导电性能较差，限制了其在超级电容器中的实际应用。在这里，我们提出了一个简单的策略，通过在NaBH 4水溶液中引入氧空位来提高TNAs的电导率。还原TNAs（rTNAs）电极与原始TNAs相比在电导率和载流子密度上表现出显著的改善。有趣的是，从5 M NaBH 4水溶液中获得的rTNAs电极在2 mV s-1的扫描速率下表现出最高的比电容23.24 mF cm-2，具有出色的长期循环稳定性。此外，还采用简单的化学浴沉积法制备了MnCo 2 O 4/TNAs电极，并在NaBH 4水溶液中进行了还原。在5 M NaBH 4水溶液中制备的还原MnCo 2 O 4/TNAs电极在2 mV s-1的扫描速率下实现了484.35 mF cm-2的高比电容。还原态MnCo 2 O 4/TNAs电极的电容和循环稳定性的提高可以归因于通过引入氧空位和TNAs的管状结构来改善MnCo 2 O 4/TNAs的导电性，从而加速电子和离子的传输。
Highly ordered TiO2nanotube arrays (TNAs) with large specific surface exhibit excellent electrochemical performance but their poor electrical conductivity limits the practical applications in supercapacitor. Here, we present a simple strategy for improving the electrical conductivity of TNAs by introduction of oxygen vacancies in NaBH4aqueous solution. The reduced TNAs (rTNAs) electrodes exhibit significant improvement on electrical conductivity and carrier density compared to those of the pristine TNAs. Interestingly, the rTNAs electrode obtained from 5 M NaBH4aqueous solution exhibits the highest specific capacitance of 23.24 mF cm−2at a scan rate of 2 mV s−1with outstanding long term cycling stability. Moreover, the reduced MnCo2O4/TNAs electrodes are also prepared by a facile chemical bath deposition method and then reduced in NaBH4aqueous solution. The reduced MnCo2O4/TNAs electrode prepared in 5 M NaBH4aqueous solution achieves a high specific capacitance of 484.35 mF cm−2at a scan rate of 2 mV s−1. The enhancement of capacitance and cycling stability of reduced MnCo2O4/TNAs electrodes can be attributed to the improved electrical conductivity of MnCo2O4/TNAs by introduction of oxygen vacancies and the tubular structure of TNAs that accelerate the electron and ions transport.