Structure and formation mechanism of carbon-doped titanium oxide nanotubes

碳掺杂氧化钛纳米管的结构及形成机理

• 批准号: 324158393
• 负责人: Professorin Dr. Uta Helbig
• 金额: --
• 依托单位: Fakultät Werkstofftechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/324158393?language=en
• 关键词: Structure; formation; mechanism; carbon; doped

Carbon-doped titanium oxide nanotubes are a promising material for several applications such as PEM fuel cells. The nanotubes have a high specific surface area, good electrical conductivity and, as first experiments showed, high oxidation stability.The tubes can be synthesized in alkaline solution via a hydrothermal process from titanium oxide. The oxide powder is transformed into multiwall nanotubes with typical inner diameters of 310 nm and a length up to 500 µm. An anatase-like structure or a titanate structure (H2Ti3O7) is suggested for the tubes. In connection with application, doping of as-produced tubes with various elements is reported in the literature including doping with carbon. The introduction of carbon is essential to achieve electrical conductivity. A common method for carbon doping is a temperature treatment in an acetylene/nitrogen gas flow. Application of this method on tubes leads to sintering and crystallization, however. As a result, only low amounts of tubes persist.To circumvent the disadvantages of thermal post processing, a new method was developed at TH Nürnberg. Instead of the tube material, the titanium oxide precursor powder is doped with carbon via carbothermal treatment. The tubes are synthesized in the hydrothermal process subsequently. The formation process of the tubes is discussed controversially up to now but of high interest for potential application. Therefore, the formation process will be investigated taking samples from the process after various time steps. The samples will be investigated regarding morphology, phase content and carbon incorporation. The information will be correlated with synthesis parameters like concentration of educts, pH value, temperature and duration.On the basis of the results regarding formation mechanism and carbon incorporation further optimization of the synthesis will be possible as a pre-requisite for application.

氧化二钛纳米管是多种应用，例如PEM燃料电池的有前途的材料。纳米管具有较高的特异性表面积，良好的电导率，并且如图所示，高氧化稳定性。可以通过氧化钛的热液过程在葡萄酒溶液中合成试管。将氧化物粉末转化为多壁纳米管，典型的内径为310 nm，长度高达500 µm。建议对管子进行解剖酶状结构或钛酸盐结构（H2TI3O7）。与应用有关，在文献中报道了包括碳掺杂在内的，掺杂具有各种元素的AS生产的管。碳的引入对于实现电导率至关重要。碳掺杂的一种常见方法是在乙炔/氮气流量中进行温度处理。但是，该方法在试管上的应用导致烧结和结晶。结果，只有低量的管子持续存在。为了避免热后加工的灾难，在Thnürnberg开发了一种新方法。氧化钛前体粉末是通过碳纤维处理掺杂的，而不是管材料。这些试管随后在热液过程中合成。到目前为止，在有争议的情况下讨论了管子的形成过程，但对潜在应用的兴趣很高。因此，在各个时间步骤之后，将研究形成过程从该过程中采集样本。将研究有关形态，相位含量和碳掺入的样品。该信息将与合成参数相关，例如归因的浓度，pH值，温度和持续时间。在形成机制和碳纳入结果的基础上，将有可能作为申请的前提。