【作者】 罗小平；

【导师】 韦志仁；

【作者基本信息】 河北大学 ， 光学工程， 2008， 硕士

【摘要】 本论文采用水热法,反应温度为180℃,反应时间为24小时。当溶液中只加入TiCl4时,合成了纯金红相TiO2晶体；当溶液中只加入SnCl4·5H2O时,合成了金红相SnO2纳米晶体；当以TiCl4和SnCl4·5H2O为前驱物,Ti4+、Sn4+离子比为1：1时,合成了掺杂Sn的金红相TiO2纳米晶,EDS、XRD和高分辨TEM显示晶体为纯金红相SnxTi1-xO2纳米晶,其中Sn掺杂的原子百分比为仅为1.1-3.2%。表明Sn从TiO2晶格中替代Ti是比较困难的。采用水热法,以市售TiO2为前驱物,10 mol/L NaOH为矿化剂,填充度68%,反应24小时。当反应温度为150℃时,合成了钛酸钠纳米管。反应温度为180℃时,合成了钛酸钠纳米纤维。在二次水热处理钛酸钠纳米纤维的实验中：当水热溶液为强酸性条件时,H+和Na+发生置换作用,形成钛酸。如果温度较高,形成的钛酸结构仍然不稳定,经过脱水过程进一步变成金红相TiO2纳米晶；当水热溶液为弱酸性条件时,纤维转化为锐钛相TiO2纳米晶,晶体长为30-100nm,宽为10-20nm,具有线状定向排列的自组织趋势；当水热溶液为碱性条件时,晶体结构未被破坏,仍为纤维状,并且,纳米纤维具有较强的界面效应,能使生成的金红相SnO2纳米晶较有规则的附在其表面。通过光催化和染料敏化太阳电池(DSSCs)实验,对所合成的纳米材料的光电性能进行了检测,结果如下：在光催化实验中,钛酸钠纳米纤维、金红相TiO2和锐钛相TiO2纳米晶,均具有光催化效应,特别是有线状定向排列的自组织趋势的锐钛相TiO2纳米聚晶,具有较好的光催化性能；在DSSCs实验中,发现钛酸钠纳米管应用于DSSCs电极材料时,电池的光电转化效率很低。较之金红相TiO2纳米晶,锐钛相TiO2纳米晶应用于DSSCs时,获得了较好的光伏效应。但相比于传统的二氧化钛P25材料,还有待进一步的提高。更多还原

【Abstract】 In this paper, pure rutile Sn-doped TiO2 nanocrystals were synthesized with TiCl4 and SnCl4 aqueous solutions as the precursor by hydrothermal method at 180℃for 24h. When with pure TiCl4 as the precursor, rutile TiO2 nanocrystals were synthesized. When with pure SnCl4 as the precursor, rutile SnO2 nanocrystals were synthesized. When with pure TiCl4 and SnCl4 as the precursor, the ratio of Ti4+/Sn4+ in the precursor solution is 1:1, the atomic concentration of the doped-Sn4+ in the synthesized rutile SnxTi1-xO2 nanocrystals was 1.1-3.2%, showed in EDX spectrums. It’s indicated that it is hard for other atoms to dope into the lattices of rutile TiO2 nanocrystals through the way of lattice-substitute.In this paper, with TiO2 as the precursor and 10 mol/L NaOH solutions as the mineralizing reagent by hydrothermal method for 24h, the fill factor was 68%. When the reacting temperature was 150℃, Na2Ti6O13 nanotubes were synthesized; When the reacting temperature was 180℃, Na2Ti6O13 nanofibers were synthesized; The synthesized nanofiber was hydrothermal retreated at 180℃for 24h; When the retreating condition was strong acid, the rutile TiO2 nano-crystals were synthesized; when the retreating condition was weak acid, the anatase TiO2 nano-crystals were synthesized, and its length and width were 30-100nm and 10-20nm respectively, charactered with wirelike directional arranged self-organizeing trend. In the strong alkali condion, the crystal structure was not changed, it was still fiber figure, and the nanofiber can strong adsorb the new synthesized SnO2 nanocrystal on its surface.In this paper, through the photocatalysis experiment, we validated that TiO2 nanocrystal and titanate nanofiber have photocatalytic properties, and the anatase TiO2 nanocrystal which charactered with wirelike directional arranged self-organizeing trend has better photocatalytic properties; Through the DSSCs experiment, we validated that the photoelectronic efficiency of DSSCs, whose thin film electrode was made of titanate nanotube, was very low. We also validated that the anatase TiO2 nanocrystal is better for DSSCs than rutile TiO2 nanocrystals. Compared with Titanium Dioxide P25, the photoelectronic properties of nanomaterials synthesized in our experiment have potential space to improve.更多还原