Hydrogenated TiO2 Nanotube Arrays for Supercapacitors
Hydrogenated TiO2 Nanotube Arrays for Supercapacitors
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用于超级电容器的氢化 TiO2 纳米管阵列
DOI：
10.1021/nl300173j
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发表时间：
2012-03-01
期刊：
影响因子：
10.8
通讯作者：
Li, Yat
中科院分区：
文献类型：
--
作者：
Lu, Xihong;Wang, Gongming;Li, Yat
我们报道了一种新的改善超级电容器用二氧化钛材料电容性能的通用策略，包括合成氢化的二氧化钛纳米管阵列(NTA)。氢化后的二氧化钛纳米管在300~600℃的氢气气氛中焙烧得到氢化的二氧化钛(记为H-二氧化钛)。在400℃下制备的氢化的二氧化钛纳米管在扫描速度为100 mV S(-1)时产生的最大比电容为3.24mF·cm(-2)，是相同条件下空气处理的比电容的40倍。重要的是，H-TiO2NTAs还表现出了显著的倍率性能，当扫描速度从10 mV增加到1000 mV S(-1)时，保持了68%的面电容，并且具有优异的长期循环稳定性，10000次循环后，初始比电容仅下降了3.1%。H-TiO2光催化剂优异的电化学电容性能归因于氢化提高了载流子密度和表面羟基密度。此外，我们还证明了H-TiO2NTAS是一种很好的支撑MnO2纳米颗粒的支架。在H-TiO2NTAs上电化学沉积纳米MnO2制备的电容器电极，在扫描速度为10 mV S(-1)(以MnO2的质量计)时，比电容达到912Fg(-1)。提高二氧化钛电极材料电容性能的能力应该会为高性能超级电容器开辟新的机会。
We report a new and general strategy for improving the capacitive properties of TiO2 materials for supercapacitors, involving the synthesis of hydrogenated TiO2 nanotube arrays (NTAs). The hydrogenated TiO2 (denoted as H-TiO2) were obtained by calcination of anodized TiO2 NTAs in hydrogen atmosphere in a range of temperatures between 300 to 600 degrees C. The H TiO2 NTAs prepared at 400 degrees C yields the largest specific capacitance of 3.24 mF cm(-2) at a scan rate of 100 mV s(-1), which is 40 times higher than thecapacitance obtained from air-annealed TiO2 NTAs at the same conditions. Importantly, H-TiO2 NTAs also show remarkable rate capability with 68% areal capacitance retained when the scan rate increase from 10 to 1000 mV s(-1), as well as outstanding long-term cycling stability with only 3.1% reduction of initial specific capacitance after 10 000 cycles. The prominent electrochemical capacitive properties of H-TiO2 are attributed to the enhanced carrier density and increased density of hydroxyl group on TiO2 surface, as a result of hydrogenation. Furthermore, we demonstrate that H-TiO2 NTAs is a good scaffold to support MnO2 nanoparticles. The capacitor electrodes made by electrochemical deposition of MnO2 nanoparticles on H-TiO2 NTAs achieve a remarkable specific capacitance of 912 F g(-1) at a scan rate of 10 mV s(-1) (based on the mass of MnO2). The ability to improve the capacitive properties of TiO2 electrode materials should open up new opportunities for high-performance supercapacitors.