碳/纳米TiO2复合材料的制备与表征

采用以N-二甲基甲酰胺(DMF)为分散剂的TiO2溶胶与聚丙烯腈(PAN)的DMF溶液共混并在聚四氟乙烯模具中浇铸成膜,然后将膜进行预氧化和碳化,制备了碳/纳米TiO2复合催化材料并对其结构进行了表征.结果表明,锐钛型TiO2粒子以10～30 nm的尺度均匀分散和镶嵌在具有乱层石墨结构的碳基底中.随着PAN基中TiO2含量的增加,复合膜表面的TiO2含量增加,但低于其内部含量,同时TiO2的晶粒发生聚并,粒子尺寸增加.乱层石墨结构碳的存在对TiO2由锐钛型转变为金红石型的相变过程有抑制作用.

Preparation and Characterization of the Carbon/Nano Titanium Dioxide Composite Materials

The composite solutions were prepared by blending the titanium dioxide sol with N, N dimethyl formamide(DMF) as solvent and the polyacrylonitrile(PAN) with DMF as solvent. The solutions were casted in the polytetrafluoroethylene mould to form membranes. After pre-oxidation and carbonization processes the carbon/nano-TiO2 composite catalytic materials were obtained and characterizated. The results showed that the anatase TiO2 particles with 10-30nm scale were dispersed and inlaid in the carbon basement with turbostratic graphite structure. With increasing the TiO2 content in PAN basement the surface TiO2 content of the composite membrane increased and the particles scale also increased. But the surface TiO2 content of the composite membrane was lower than that in interior. The turbostratic graphite had inhibitory action for the phase transition of anatase TiO2 to rutile. Thus the phase transition temperature increased.