Structure and Photoluminescence Study of TiO2 Nanoneedle Texture along Vertically Aligned Carbon Nanofiber Arrays
Structure and Photoluminescence Study of TiO2 Nanoneedle Texture along Vertically Aligned Carbon Nanofiber Arrays
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DOI：
10.1021/jp8060653
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发表时间：
2008-11-06
影响因子：
3.7
通讯作者：
Jiang, Hongxing
中科院分区：
文献类型：
--
作者：
Liu, Jianwei;Li, Jun;Jiang, Hongxing
采用金属-有机化学气相沉积的方法，在垂直排列的纳米碳纤维阵列上沉积了一层二氧化钛-碳纳米纤维复合层叠结构。随着沉积时间从10 min增加到60 min， TiO(2)涂层由颗粒状的保形超薄膜转变为沿纳米碳纤维侧壁的纳米针状结构。x射线衍射表明，tio2形成的锐钛矿晶体的相干长度大于50 nm，与透射电镜图像吻合较好。在室温和10k下分别取光致发光光谱。没有光致发光，说明在这种核壳杂化结构中，TiO(2)中的电子-空穴复合被完全淬灭。在二氧化钛-碳纳米纤维异质结处，电荷分离可能更有效。纳米针状结构极大地增加了TiO(2)的有效表面积，同时通过高导电性的碳纳米纤维芯保持更有效的电线。这种层次化结构可作为染料敏化太阳能电池的新型负极材料。
A hybrid TiO(2)-carbon nanofiber hierarchical nanostructure has been fabricated by the metal-organic chemical vapor deposition of a TiO(2) layer onto the vertically aligned carbon nanofiber array. As the deposition time increases from 10 to 60 min, the TiO(2) coating changes from the particulated conformal ultrathin film to a nanoneedle-hke texture along the sidewall of the carbon nanofibers. X-ray diffraction indicates that the TiO(2) form anatase crystals with the coherent length over 50 nm, in good agreement with transmission electron microscopy images. Photoluminescence spectra are taken at both room temperature and 10 K. The absence of photoluminescence emission indicates that the electron-hole recombination in TiO(2) is completely quenched in such core-shell hybrid structure. The charge separation may be much more effective at the TiO(2)-carbon nanofiber heterojunction. The nanoneedle-like texture drastically increases the effective surface area of the TiO(2) while maintaining a much more effective electrical wiring through the highly conductive carbon nanofiber core. Such hierarchical architecture may be used as a novel anode material for dye-sensitized solar cells.