论文部分内容阅读
采用全氟化离子聚合物薄膜(钠型Nafion薄膜)作模板合成了平均直径为4.0nm的TiO2晶体粒子。利用高分辨电子显微镜(HRTEM)、X-射线衍射仪(XRD)和紫外-可见光谱仪(UV-VIS),对Nafion中TiO2的含量、粒子大小分布、相变条件、纳米晶体微观型貌及其结构、Nafion薄膜结构和TiO2粒子形成机理等进行了研究。研究结果表明,Nafion中Ti4+含量不仅与起始原料有关,还与起始物浓度有关。TiO2在Nafion中的形成速度主要受控于水在膜中的扩散速度,而TiO2晶体粒子的大小与分布则取决于Nafion的孔径,与起始原料种类以及晶化条件无关。文中还探索了无定型TiO2转变成单分散晶体的各种途径,详细讨论了TiO2晶体粒子合成的影响因素。
The perfluorinated ionic polymer film (sodium Nafion film) was used as a template to synthesize TiO2 crystal particles with an average diameter of 4.0 nm. The content of TiO2 in Nafion, the size distribution of particles, the phase transition conditions, the microcrystalline morphology of nanocrystals and their microscopic morphology were characterized by HRTEM, XRD and UV-VIS. Structure, Nafion film structure and TiO2 particle formation mechanism were studied. The results show that the Nafion Ti4 + content not only with the starting material, but also with the starting material concentration. The formation rate of TiO2 in Nafion is mainly controlled by the diffusion rate of water in the film. The size and distribution of TiO2 crystal particles depend on the pore size of Nafion, which is independent of the type of starting materials and the crystallization conditions. The paper also explores various ways to convert amorphous TiO2 into monodisperse crystals. The influencing factors of the synthesis of TiO2 crystal particles are discussed in detail.