多壁碳纳米管结构对复合光催化剂催化效果的影响

Effects of the structure of multi-wall carbon nanotubes on photocatalytic efficiency of composite photocatalysts

采用溶胶-凝胶法制备了多壁碳纳米管负载纳米TiO2的复合光催化剂（TiO2/MWCNTs）,以偶氮类染料甲基橙为目标污染物,在自制的光催化反应器上进行了光催化降解反应实验。主要研究同一甲基橙初始浓度（C0）下,多壁碳纳米管不同管长和管径对复合光催化剂催化效果的影响。结果表明：该降解反应可用一级反应动力学方程描述,反应速率常数k随着多壁碳纳米管管长和管径的增大而增大;与纯纳米TiO2相比,复合光催化剂对甲基橙的降解率提高了6%-18%,反应速率常数为前者的1.19-2.11倍;采用复合光催化剂的甲基橙光降解溶液自行沉降分离效果较好,静止沉降60m in后达到沉降平衡,剩余浊度为8.5 NTU,下降了90.6%。

The composite photocatalysts（TiO2/MWCNTs）of TiO2 nano-particles attached on mutil-walled carbon nanotubes were prepared by the sol-gel method.Using azo dyes methyl orange as the goal pollutant,the photocatalytic degradation experiments were carried out on the self-made photoreactor.The paper mainly investigated the effects of different tube diameters and length of mutil-walled carbon nanotubes on the photocatalytic efficiency of the composite photocatalysts under the same concentration of methyl orange（C0） The results of kinetic study showed that： the degradation reaction could be expressed by first-order reaction kinetic model, and the reaction rate constant（k） increased with the increase of tube diameter and length of mutil-walled carbon nanotubes. Compared with that of nano-TiO2 , the degradation rate of the composite photocatalyst for methyl orange was enhanced by 6% - 18% , and the reaction rate constant was 1. 19 -2.11 times of that of nano-TiO2. Using the composite photocatalyst, the photodegradation solution of methyl orange can be separated better. After the static sedimentation equilibrium was reached at 60 min, the residual turbidity was 8.5 NTU and decreased by 90.6%.