双微乳液法制备掺杂Fe~(3+)的纳米TiO_2及其光催化性能

为了研究双微乳液法在制备纳米级光催化剂的应用,以TiCl4和NH3.H2O为原料,采用十六烷基三甲基溴化铵-正丁醇-环己烷-水微乳体系制备Fe3+掺杂纳米TiO2,对粉末的晶体结构进行X射线衍射表征,并以其对p-甲酚的降解考察其光催化活性。结果表明,在较小的掺杂量时,Fe3+掺杂量的提高可以提高TiO2的光催化活性,进一步提高掺杂量将引起光催化活性的降低;掺杂Fe3+可导致纳米TiO2的粒径减小;Fe3+的半径较小以及Fe2O3的熔点较低均有利于TiO2从锐钛矿向金红石的相变;当Fe3+掺杂摩尔分数为0.06%,煅烧温度为550℃时,纳米TiO2的光催化活性最高,此时形成TiO2的锐钛矿和金红石相的混晶;乳液中含水量也会影响晶相的组成和粒径大小,随着含水量增加产物中出现了一定比例的金红石相。

Fe3+ Doped TiO2 Nano-particles Prepared by Double Microemulsion Method and Photocatalytic Activity

In order to research the application of double microemulsion method for preparing nano-sized catalysts,Fe3+ doped TiO2 nano-particles were obtained in microemulsion of CTAB-butanol-cyclohexane-H2O with TiCl4 and NH3·H2O as raw meterials.The crystal structure of Fe3+ doped TiO2 nano-particles was characterized by XRD and the degradation of p-cresol was investigated for the photocatalytic activity of them.The results show that the photocatalytic activity increases with the increasing doping content of Fe3+ in a certain range and decreases with further increasing of doping content.The doped Fe3+ ions lead to decrease the particle size of TiO2 nano-particles.The small radius of Fe3+ and low melting point of Fe2O3 can promote the phase transitions of anatase to rutile.When the doping molar fraction of Fe3+ is 0.06%,Fe3+ doped TiO2 nano-particles calcined at 550 ℃ show the highest photocatalytic activity and emerge the mixed crystal of anatase and rutile.