中文摘要：

采用多羟基法一步合成了具有可见光催化活性的水分散性N掺杂TiO2纳米颗粒,其中四异丙醇钛（TTIP）作为钛源,二乙二醇（DEG）作为反应溶剂,谷氨酸作为表面修饰剂和氮源。所得TiO2纳米颗粒在pH≥6.54的水溶液中可以很好的分散,并能稳定保持一星期。以甲基橙为目标降解物,研究了水分散性N掺杂TiO2在可见光下的光催化活性。结果显示,与未经掺杂的TiO2相比,所制得的N掺杂TiO2有良好的可见光催化活性。除此之外还通过改变气体氛围和添加捕获剂对水分散性N掺杂TiO2降解甲基橙（MO）的光催化机理进行了研究。本方法制备的TiO2因具有优越的水分散性和良好的可见光催化活性,在光动力治疗（PDT）中有极好的应用前景。

英文摘要：

A one-step polyol process to directly synthesize water-dispersible N-doped TiO2 nanoparticles with excellent visible light photocatalytic ability by employing TTIP as the titanium source,diethylene glycol（ DEG） as the solvent and glutamic acid as the surface modifier and nitrogen source. The obtained TiO2 nanoparticles were well dispersible in water at pH ≧ 6. 54 and the resulting aqueous dispersion remains stable for a week. The photocatalytic activities were evaluated via the degradation rate of methyl orange under visible light irradiation. The result reveals that the water-dispersible N-doped TiO2 nanoparticles had excellent visible light photocatalytic activity compared with the un-doped TiO2. In addition,the mechanism of photocatalytic activity was investigated through gas atmosphere changing and active species capturing test. Owing to the excellent water-dispersibility and visible light photocatalytic activity,the obtained water-dispersible N-doped TiO2 had potential to be used in photodynamic therapy（ PDT）.