化学学报 ›› 2011, Vol. 69 ›› Issue (24): 2929-2938.DOI: 10.6023/A1103011 上一篇    下一篇

研究论文

锐钛矿型TiO2表面吸附甲醛的密度泛函理论研究

刘子忠*,1, 韩飞1, 封继康2,3, 徐爱菊1, 崔文颖1   

  1. (1内蒙古师范大学化学与环境科学学院 功能材料物理与化学自治区重点实验室 呼和浩特 010022)
    (2吉林大学理论与计算化学国家重点实验室 长春 130023)
    (3吉林大学化学院 长春 130023)
  • 投稿日期:2011-03-01 修回日期:2011-06-18 发布日期:2011-09-05
  • 通讯作者: 刘子忠 E-mail:zizhliu@yahoo.com.cn
  • 基金资助:

    全氟酸(羧酸和磺酸)降解机理的理论研究

The Density Function Theory Study on Formaldehyde Adsorbed on Anatase TiO2 Surface

Liu Zizhong*,1; Han Fei1; Feng Jikang2,3; Xu Aiju1; Cui Wenying1   

  1. (1 College of Chemistry and Environmental Science, Inner Mongolia Key Laboratory for Physics and Chemistry of Functional Materials, Inner Mongolia Normal University, Hohhot 010022)
    (2 State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023)
    (3 The College of Chemistry, Jilin University, Changchun 130023)
  • Received:2011-03-01 Revised:2011-06-18 Published:2011-09-05
  • Contact: zizhong liu E-mail:zizhliu@yahoo.com.cn
  • Supported by:

    Theoretical study on degradition mechenism for perfluorinated acids(perfluoro carboxylic acids and perfluoro sulfic acids)

应用密度泛函理论优化了锐钛矿型TiO2 (001), (110)和(100)晶面结构, 发现(001)晶面能量最低. 通过对甲醛吸附到(001)面的6种初始猜测方式的几何优化, 发现从甲醛H—C—O侧面吸附方式为最稳定的吸附方式, 吸附能最大, 发生了化学吸附. 吸附后甲醛中C—H键增长, 键变弱, C—O键缩短, 键增强. 甲醛中C原子与邻近层Ti和O原子间电子云发生重叠, 有新的Ti—O和Ti—C键生成. 吸附前后锐钛矿型TiO2 (001)能隙从2.88 eV降低为2.50 eV, 光催化吸收波长从431增加到496 nm.

关键词: 锐钛矿, 吸附, 甲醛, 密度泛函理论

The structures of (001), (110) and (100) crystal faces, as well as the structure of formaldehyde absorbed on the (001) face of anatase by six kinds of modes were optimized with density function theory (DFT). It is found that the energy of (001) crystal face is the lowest, and that the mode of formaldehyde absorbed on the (001) face of anatase beside H—C—O is the most stable, and has the biggest absorption energy, and taking place chemical absorption. When this absorption was conducted, the C—H bond length increases, and bond strength weakens, while the C—O bond length decreases, and bond strength increases. Meantime, the overlaps of the electronic clouds between titanium and oxygen atom in neighboring layer, and between titanium and carbon atom in formaldehyde, as well as new Ti—O and Ti—C bonds were found. The energy gap between the before and after adsorptions on anatase TiO2 (001) is decreased from 2.88 to 2.50 eV, the wave length of adsorption light is increased from 431 to 496 nm.

Key words: anatase, adsorption, formaldehyde, density function theory