Abstract:

Titanium dioxide nanotubes were prepared by the hydrothemeral method, and characterized with TEM, XRD and BET.The anatase products, with an external diameter of 5—7 nm, a wall thickness of about 1 nm and a length of 200—300 nm, had a specific surface area of 276 m²·g^-1.Their adsorption of COD, catalytic activity and reaction kinetics for ozonation in landfill leachate solution were studied.The removal rate of COD by using O₃/UV/TiO₂ nanotubes in 60 minutes was 20.83% better than using O₃/UV/P25 (Degussa, Germany), and 32.65% better than using O₃/UV (Yingze Corp., China).In landfill leachate solution, the maximal absorption of COD on 0.5 g TiO₂ nanotubes, contributing 10.14% of the total COD removal rate, was 1.34 times as that on 0.5 g P25 at 293 K.The overall apparent rate constant of O₃/UV/TiO₂ nanotubes was 1.19 times as that of O₃/UV/P25, and 1.80 times as that of O₃/UV in 2 hours.Two equations between k and T were obtained, and the total apparent activation energy of O₃/UV/TiO₂ nanotubes was 2.925 kJ·mol^-1 less than that of O₃/UV/P25.

Key words:

纳米管, 水热法, 催化臭氧化, 反应动力学, 表观活化能

摘要：

用水热法制备了高比表面积的TiO₂纳米管，通过TEM、XRD及BET进行物化表征，试验得到外径5～7 nm、壁厚1 nm左右、长200～300 nm、比表面积276 m²·g^-1的锐钛型TiO₂纳米管。试验考察了TiO₂纳米管的吸附性能及对O₃的催化性能和本征反应动力学，结果显示：60 min时O₃/UV/TiO₂纳米管较O₃/UV/P25和O₃/UV对垃圾渗滤液的COD去除率分别提高了20.83%和32.65%；293 K时0.5 g TiO₂纳米管对COD的最大吸附量为P25的1.34倍，对COD去除率贡献为10.14%； 2 h内O₃/UV/TiO₂纳米管工艺的总反应表观速率常数k分别是O₃/UV/P25工艺的1.19倍和O₃/UV工艺的1.80倍；得出两种催化工艺k-T关系方程，反应表观活化能E_a,nanotube比E_a,P25降低了2.925 kJ·mol^-1。

关键词:

纳米管, 水热法, 催化臭氧化, 反应动力学, 表观活化能