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采用水热法合成钛酸钾(K2Ti8O17)纳米棒,并将它作为前驱体水热转晶合成TiO2纳米晶,同时通过在水热体系中引入稀土元素La3+实现对TiO2的La掺杂.考察了不同条件下钛酸盐向TiO2的转晶过程,发现水热溶液的pH值、温度以及预处理步骤对转晶过程有很大的影响.利用X射线衍射以及透射电子显微镜对样品的晶相和形貌进行了表征.利用电感耦合等离子体原子发射光谱测量了所合成的La掺杂TiO2样品中的La含量.通过在紫外光下降解甲基橙(MO,10mg/L)测试了La掺杂TiO2样品的光催化性能.结果表明La掺杂后TiO2的光催化活性大大提高.在0.15mol/LLa3+浓度下180°C水热合成的La掺杂TiO2样品显示了最佳的光催化活性.其对MO的光催化降解反应常数高达0.11min1,大约是空白TiO2样品的9.20倍,P25TiO2的3.69倍.
Hydrothermal synthesis of potassium titanate (K2Ti8O17) nanorods and hydrotalcites as precursors for the synthesis of TiO2 nanocrystals, and at the same time through the introduction of rare earth elements La3 + in the hydrothermal system to achieve La doped TiO2. The results show that the pH, temperature and pretreatment steps of hydrothermal solution have a great influence on the crystal growth process.Using X-ray diffraction and transmission electron microscopy to analyze the crystal phase and Morphology were characterized by means of inductively coupled plasma atomic emission spectroscopy.The La content in the La-doped TiO2 samples was measured.The La-doped TiO2 samples were tested by UV degradation of methyl orange (MO, 10 mg / L) The results showed that the photocatalytic activity of TiO2 was greatly enhanced after La doping.The La doped TiO2 samples synthesized by hydrothermal synthesis at 180 ° C showed the best photocatalytic activity at a concentration of 0.15mol / The photocatalytic degradation reaction constant is as high as 0.11min1, which is about 9.20 times that of blank TiO2 sample and 3.69 times that of P25TiO2.