Chem. J. Chinese Universities ›› 2016, Vol. 37 ›› Issue (5): 920.doi: 10.7503/cjcu20160028

• Physical Chemistry • Previous Articles     Next Articles

First-principle Calculations on Electronic Structures and Optical Properties of α, β, γ, δ, ε, η-Bi2O3

LI Tan, ZHANG Xiaochao*(), WANG Kai, LI Rui, FAN Caimei*   

  1. College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China
  • Received:2016-01-13 Online:2016-05-10 Published:2016-04-12
  • Contact: ZHANG Xiaochao,FAN Caimei E-mail:zhangxiaochao@tyut.edu.cn
  • Supported by:
    † Supported by the Youth National Natural Science Foundation of China(No.21506144), the Natural Science Foundation for Young Scientists of Shanxi Province, China(No.2014021019-3) and the Science and Technology Innovation Project of Shanxi Higher Education Institutions, China(No.2014115)

Abstract:

A theoretical investigation on the geometric structures, band structures, densities of states and optical properties of Bi2O3 in six crystalline phases(α, β, γ, δ, ε and η) was carried out using CASTEP(Cambridge Sequential Total Energy Package) module based on the density functional theory. The calculation results show that the α, ε and η phases belong to the layered structure, in which α and ε phases are —Bi—O— single-layer structure and η phase is consisted of the —Bi—O— double-layers structure, while the β, γ, and δ phases are —Bim—On— staggered structure, in which the δ phase is intensively staggered and its band structure exhibits the conductor characteristic. The conduction bands of all the six crystalline phases are mainly generated by Bi6p states, while the valence bands are contributed by O2p states. The potential of the six phases are lower than the H2O/O2, indicating that they have the higher oxidative ability, which is in good agreement with the reported experimental result(γ-Bi2O3>β-Bi2O3>α-Bi2O3>δ-Bi2O3) of the photocatalytic oxidative ability. The reduction potential of the conduction band is lower than H2/H2O, we thus speculate that pure Bi2O3 has hardly the catalytic ability of hydrogen production. The γ and δ phases have the longer initial response wavelengths, implying that they should have the infrared excitation property. Our calculations can provide basic and reliable theoretical data for the synthesis and study of Bi2O3 materials with partial infrared excitation and wide spectral response range, and afford significant guidance for the development and application in the Bi2O3-based materials.

Key words: Bi2O3 crystalline phase, First-principle, Electronic structure, Optical property

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