物理化学学报 >> 2010, Vol. 26 >> Issue (03): 663-668.doi: 10.3866/PKU.WHXB20100317

催化和表面结构 上一篇    下一篇

N-TiO2/ZnO复合纳米管阵列的掺杂机理及其光催化活性

翟晓辉, 龙绘锦, 董江舟, 曹亚安   

  1. 南开大学物理学院, 天津 300071; 南开大学泰达应用物理学院, 天津 300457
  • 收稿日期:2009-08-19 修回日期:2009-11-26 发布日期:2010-03-03
  • 通讯作者: 曹亚安 E-mail:caoyaan@yahoo.com

Doping Mechanism of N-TiO2/ZnO Composite Nanotube Arrays and Their Photocatalytic Activity

ZHAI Xiao-Hui, LONG Hui-Jin, DONG Jiang-Zhou, CAO Ya-An   

  1. College of Physics, Nankai University, Tianjin 300071, P. R. China; Teda Applied Physics School, Nankai University, Tianjin 300457, P. R. China
  • Received:2009-08-19 Revised:2009-11-26 Published:2010-03-03
  • Contact: CAO Ya-An E-mail:caoyaan@yahoo.com

摘要:

以ZnO纳米柱阵列为模板, 采用溶胶-凝胶法制备出TiO2/ZnO和N掺杂TiO2/ZnO的复合纳米管阵列. 扫描电镜(SEM)、X射线光电子能谱(XPS)和紫外-可见漫反射吸收光谱(UV-Vis)的结果表明: 两种阵列的纳米管均为六角形结构, 直径约为100 nm, 壁厚约为20 nm; 在N-TiO2/ZnO复合纳米管阵列中, 掺入的N离子主要是以N-Ox、N-C和N-N的形式化学吸附在纳米管表面, 仅有少量的N离子以取代式掺杂的方式占据TiO2晶格O的位置; 表面N物种形成的表面态能级和取代式掺杂导致带隙的窄化, 增强了纳米管阵列的光吸收效率, 促进了光生载流子的分离. 光催化实验结果表明, N离子的掺杂有利于N-TiO2/ZnO复合纳米管阵列光催化活性的提高.

关键词: 光催化, TiO2/ZnO复合纳米管阵列, N掺杂, 掺杂机理

Abstract:

TiO2/ZnO and N-doped TiO2/ZnO composite nanotube arrays were synthesized by the sol-gel method using ZnOnanorod arrays as a template. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance UV-Vis spectroscopy (UV-Vis) were used to characterize the samples. The nanotubes had a uniform hexagonal shape. The diameter and wall thickness of the nanotubes were about 100 nm and 20 nm, respectively. Some N dopants were substitutionally doped into the TiO2 lattice, while the N-Ox, N-C, and N-N were chemically absorbed onto the surface of the TiO2/ZnO composite nanotubes. Dopant-induced narrowing of the bandgap resulted from the doping of N ions into the TiO2 lattices. The surface N species enhanced the visible-light response and promoted the separation of photogenerated carriers. Compared with the TiO2/ZnO composite nanotube arrays, the N-TiO2/ZnO composite nanotube arrays exhibited higher photocatalytic activity.

Key words: Photocatalysis, TiO2/ZnO composite nanotube array, N doping, Doping mechanism

MSC2000: 

  • O648