溶剂热合成条件对氮掺杂TiO2形貌及性能的影响

EFFECTS OF SOLVOTHERMAL SYNTHESIS CONDITIONS ON THE MORPHOLOGY AND PERFORMANCE OF NITROGEN-DOPED TiO2

考察了在乙二胺体系下氮掺杂TiO2的合成机理，以及溶剂热体系酸碱性、反应时间、原料等对氮掺杂TiO2形貌的影响，并考察其在可见光条件下的光催化氧化活性。结果表明，碱性条件和反应时间的延长有利于TiO2纳米棒的生长；后处理的方法无法实现P-25 TiO2形貌的转变；乙二胺溶剂热处理后P-25 TiO2的紫外-可见吸收光谱吸收边带明显红移，说明在乙二胺的碱性环境中，TiO2晶体结构被部分破坏，为氮原子的掺杂提供了条件。氮元素的掺杂量和棒状结构共同影响氮掺杂TiO2纳米棒在可见光和紫外光条件下的光催化活性。在可见光条件下，反应6h后，氮含量为1．7％的催化剂的苯酚降解率高达97．9%，其TOC降解率为95％。

The synthesis mechanism of nitrogen doped TiO2 in ethylenediamine system, and the effects of pH environment, reaction time and initial materials on its morphology and photoeatalytic activity were investigated. The results showed that alkaline environment and long reaction time were propitious to growth of TiO2 nanorods. Postsynthesis can not make the morphology transformation of P-25 TiO2. However, the absorption edge of P-25 TiO2, after post-synthesis was obviously red-shifted. It can be concluded that partly destruction of TiO2 crystal structure was propitious to nitrogen doping. Nitrogen content and nanorod structure affect photoeatalytic activity of catalysts under the illumination of visible light and ultraviolet light. The 97.9% conversion of phenol with TOC degradation ratio of 95% was observed in the 1.7 % nitrogen-doped TiO2 under visible light illumination.