【作者】 武胜岩；

【导师】 邓凤萍；

【作者基本信息】 长春理工大学 ， 应用化学， 2008， 硕士

【摘要】 TiO₂介孔材料因其在光催化、催化剂载体、传感器、电化学器件等方面具有种种潜在的用途而备受关注,已经成为材料科学一个崭新的研究方向。在处理有机废水方面显示了比纳米TiO₂更高的光催化效率。在特定情况下显示出了很广阔的应用前景。本研究首次采用新型材料Gemini1231作为模板剂,用溶胶-凝胶法在室温下合成TiO₂。采用差热分析、X射线衍、N₂吸附-脱附、TEM等对样品进行了表征。结果表明,在钛源和模板剂比例为0.75时,具有较好的介孔结构,比表面积可达383.8m²/g,最可几孔径为5.4nm,晶粒的尺寸为22.60nm,XRD测试发现较强的锐钛矿型特征峰而未发现金红石相特征衍射峰,说明本实验制备的介孔TiO₂为稳定锐钛矿型。通过小角X射线衍射分析和TEM照片发现,产物为规整的介孔结构。由于TiO₂可利用的激发光源仅限于紫外光,而太阳光中仅含4%左右的紫外光,远远达不到利用TiO₂处理各种废水的要求。过渡金属离子掺杂可在TiO₂晶格中引入缺陷位置或改变结晶度,从而影响电子与空穴的复合,某些金属离子的掺入还可以扩展光吸收波长的范围,因此本研究尝试在介孔材料中掺入Fe³⁺和V⁵⁺,从而提高介孔TiO₂的催化活性。测试结果表明,适量Fe³⁺和V⁵⁺掺杂对TiO₂介孔结构影响显著,但可以大幅度提高介孔TiO₂的活性。通过光催化降解甲基橙实验得到了最佳的配比。更多还原

【Abstract】 Mesoporous TiO₂ materials which because of their photocatalytic, catalyst carrier, sensors, electrochemical devices, and other aspects of the potential uses,are concerned recently, has become a new research direction on Materials science.It shows better photocatalytic efficiency than nano-particle TiO₂ in the degration of organic waste water,and shows broad application prospects in particular cases.First applied Gemini1231 as template in this experiment, samples were synthesized by sol-gel method at room temperature and characterized by differential thermal analysis, X-ray, N2 adsorption-desorption, degradation experiments. The results showed that when the titanium source and template ratio of 0.75, had better mesoporous structure, and specific surface area was up to 383.8m²/g, the size of the most pores was about 5.4 nm in diameter,the grain size was 22.60 nm. The strong anatase characteristic peaks was found in XRD spectra but the rutile phase diffraction peaks was not found.It proved that the preparation of mesoporous TiO₂ at this experiment was stability anatase. Small-angle X-ray diffraction analysis showed that the samples were regular mesoporous structure.However,the excitation can be used is limited to UV light. UV ligh is only about 4% of the sun light, which is far less reach the requirement in degration of various waste water.Transition metal ion doping in TiO₂ can introduce defects position or change crystallinity, thus affecting electron and hole recombination.The scope of optical absorption wavelength can be expanded by incorporating certain metal ions.So Fe³⁺ and V⁵⁺ were doped in this experiment thereby enhancing the catalytic activity of mesoporous TiO₂.Test results showed that the appropriate Fe³⁺ and V⁵⁺ doping did a little effect in mesoporous structure, but the photocatalytic activity of mesoporous TiO₂ was improved substantially.At last,the best ratio was found Through the experiment of photocatalytic degradation of methylorange.更多还原