离子交换法制备钛酸钾纳米纤维及其表征

Preparation and Characterization of Potassium Titanate Nanofiber by Ion-exchanging

采用离子交换法,以KOH溶液与钛酸纳米管（H2Ti2O4（OH）2）反应,制备了钛酸钾纳米纤维。透射电镜（TEM）和X-射线衍射分析（XRD）结果表明,经过离子交换,形貌由纳米管变为纳米纤维,晶体结构亦发生改变。利用原子吸收分光光度法、比色法和X-射线光电子能谱（XPS）对离子交换产物的Ti、K元素的原子比和化学价态进行分析,结果表明,离子交换产物的经验式为：K1.34H0.66Ti2O4（OH）2。与H2Ti2O4（OH）2纳米管相比,钛酸钾纳米纤维的热稳定性较好,700℃以上的热处理才使其晶型发生改变,出现单斜型的K2Ti4O9。高温处理导致钛酸钾纳米纤维的直径增加,但仍保持较大长径比。该材料的BET比表面为104m2·g^-1。

Potassium titanate nanofibers K1.34H0.66Ti2O4（OH）2 were prepared by using ion-exchange reaction between KOH solution and titanic acid nanotube （H2Ti204（OH）2）. Transmission electron microscopy （TEM） and X-ray diffraction （XRD） results showed that the nanotubes changed into nanofibers and the crystalline structure altered, K/Ti atomic ratio, chemical state of K and Ti elements for the product were determined by means of atomic absorption spectrophotometry, colorimetric method, and X-ray photoelectron spectroscopy. The results indicated that the empirical formula of the product isK1.34H0.66Ti2O4（OH）2. Comparing with H2Ti204 （OH）2 nanotubes, the thermal-stability of potassium titanate nanofibers is higher. At T 〉 700℃, the crystalline structure of this material changed into monoclinic phase K2Ti409. High temperature treatment results in their sizes increasing, but the aspect ratio is still high. The BET surface area of the material is 104m^2. g^-1.