化学学报 ›› 2006, Vol. 64 ›› Issue (13): 1329-1333. 上一篇    下一篇

研究论文

热处理温度对铬掺杂二氧化钛表面结构和性质的影响

高碧芬1,2,马颖1,曹亚安3,姚建年*,1   

  1. (1中国科学院化学研究所 光化学重点实验室 北京100080)
    (2中国科学院研究生院 北京100039)
    (3南开大学物理学院 天津300071)
  • 投稿日期:2005-11-01 修回日期:2006-03-02 发布日期:2006-07-14
  • 通讯作者: 姚建年

Effect of Annealing Temperature on the Surface Structure and Properties of Chromium Doped Titania

GAO Bi-Fen1,2, MA Ying1, CAO Ya-An3, YAO Jian-Nian*,1   

  1. (1 Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080)
    (2 Graduated School of Chinese Academy of Sciences, Beijing 100039)
    (3 College of Physics, Nankai University, Tianjin 300071)
  • Received:2005-11-01 Revised:2006-03-02 Published:2006-07-14
  • Contact: YAO Jian-Nian

采用溶胶-凝胶法制备了铬掺杂二氧化钛(Cr-TiO2), 并对经过不同温度烧结的Cr-TiO2的结构、吸收光谱及样品中铬的氧化态等进行了表征. 实验结果表明, 在不高于723 K的温度烧结后, 铬以Cr3+的氧化物和Cr6+的铬酸盐或重铬酸盐的形式存在于TiO2表面. 随着热处理温度的提高, Cr6+的含量逐渐增多. Cr-TiO2在可见区400~550 nm的吸收带是由Cr3+4A24T1跃迁和O→Cr6+的1t1→2e电荷转移等引起的, 620~800 nm的吸收则是Cr3+4A24T2跃迁的结果. 前者随着烧结温度的升高而增强, 后者则随着温度升高而下降.

关键词: 半导体, 掺杂, 二氧化钛, 铬, 可见光吸收

Chromium doped titanium dioxide Cr-TiO2 was prepared by the sol-gel method. The effects of annealing temperature on the crystal structure, oxidation states of chromium, and UV-vis absorption properties of Cr-TiO2 were investigated in details. Experiment results showed that chromium mainly existed on TiO2 surface as Cr2O3 and chromate or dichromate of Cr6+ in Cr-TiO2 annealed at temperature no higher than 723 K. The content of Cr6+ was increased with the increase of temperature. The visible light absorption of Cr-TiO2 within 400~550 nm should be attributed to the 4A24T1 transition of Cr3+and the O→Cr6+charge transfer (1t1→2e). The absorption within 620~800 nm was due to the 4A24T2 transition of Cr3+. The former was strengthened with the increase of annealing temperature, whereas the latter was weakened.

Key words: semiconductor, doping, titanium dioxide, chromium, visible light absorption