无定型碳包覆的TiO2纳米管阵列的制备及表征

Preparation and characterization of TiO2 nanotube arrays coated with amorphous carbon

摘要:

本文通过将水热碳化法和阳极氧化法相结合制备了具有良好电化学性能的无定型碳包覆的混晶型TiO2纳米环阵列(C@TNTs)。利用扫描电镜(SEM)、拉曼光谱(Raman)、X射线衍射(XRD)、透射电镜(TEM)和X射线光电子能谱(XPS)及电化学测试等表征方法对未修饰的TNTs试样和在550 °C、650 °C和750 °C退火温度下得到无定形碳修饰的C@TNTs分别进行了表征分析。结果表明：水热碳化法可以将厚度约为3.4~6.5 nm无定型碳层均匀地包覆在TiO2纳米管阵列上，但却不会影响其形貌和结构；其中C@TNTs-550、C@TNTs-650和C@TNTs-750的放电比容量分别为2.83 mF·cm-2、6.52 mF·cm-2和1.48 mF·cm-2，相较于未修饰前的TNTs分别提升了27、62和14倍；此外，在TiO2纳米管阵列中引入一定量的金红石相有利于其电化学性能的提升。

Abstract:

In this paper, an amorphous carbon-coated mixed-crystal TiO2 nanoring array (C@TNTs) with good electrochemical properties was prepared by combining the hydrothermal carbonization method and anodizing method. Scanning electron microscopy (SEM), Raman spectroscopy (Raman), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and electrochemical methods were used to characterize and analyze respectively the unmodified TNTs sample and the C@TNTs samples that obtained at annealing temperatures of 550 °C, 650 °C and 750 °C. The results show that the hydrothermal carbonization method can uniformly coat an amorphous carbon layer with a thickness of about 3.4 to 6.5 nm on the TiO2 nanotube array, but it will not affect its morphology and structure. The specific discharge capacities of C@TNTs-550, C@TNTs-650 and C@TNTs-750 are 2.83 mF·cm-2, 6.52 mF·cm-2and 1.48 mF·cm-2, which are 27, 62 and 14 times higher than the unmodified TNTs, respectively. What’s more, the introduction of a certain rutile phase in TiO2 nanotube array is conducive to the improve its electrochemical performance.