氟掺杂纳米TiO_2薄膜的低温制备及其光催化性能

Low-Temperature Preparation and Photocatalytic Performance of F-Doped Nanosized TiO_2 Thin Film

以氟化铵为氟源,采用水热法制得氟掺杂TiO2(FTO)溶胶,并通过浸渍提拉法在低温下制备了FTO薄膜.其中在120oC下水热处理10h所得的TiO2溶胶制备的薄膜均匀透明,具有较高的光催化活性.氟掺杂后的TiO2晶粒尺寸并未发生明显变化,但薄膜的光催化活性显著升高.F/Ti摩尔比为0.01时,FTO薄膜的光催化活性最高,比TiO2薄膜的活性升高了23%.X射线光电子能谱结果表明,氟掺杂TiO2中的氟离子存在晶格取代掺杂和表面化学吸附两种形式.这两种氟离子的共同作用是FTO薄膜光催化活性升高的主要原因.

F-doped TiO2 （FTO） sol was prepared using NH4F as the fluorine precursor by a hydrothermal method. FTO thin film was then prepared via dip-coating. The TiO2 thin film prepared from the TiO2 sol that was hydrothermally treated at 120 ℃ for 10 h had preferable transparence and high photocatalytic activity. F doping did not significantly change the grain size of TiO2 but greatly enhanced the photocatalytic activity of the TiO2 film. The optimal doping concentration of F corresponded to F/Ti molar ratio of 0.01. The photocatalytic activity of the FTO thin film was 23% higher than that of TiO2 thin film. X-ray photoelectron spectroscopy results showed that there were two forms of F element in the FTO thin film： surface chemically adsorbed F and substituent lattice F. Both surface adsorbed F and substituent lattice F played a role in the photocatalytic activity enhancement of the FTO thin film.