中国物理B ›› 2011, Vol. 20 ›› Issue (10): 102101-102101.doi: 10.1088/1674-1056/20/10/102101

• NUCLEAR PHYSICS • 上一篇    下一篇

Density functional theory study of NO2-sensing mechanisms of pure and Ti-doped WO3 (002) surfaces

胡明, 王巍丹, 曾晶, 秦玉香   

  1. School of Electronics and Information Engineering, Tianjin University, Tianjin 300072, China
  • 收稿日期:2011-05-18 修回日期:2011-06-07 出版日期:2011-10-15 发布日期:2011-10-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 60771019 and 60801018), Tianjin Key Research Program of Application Foundation and Advanced Technology, China (Grant No. 11JCZDJC15300), Tianjin Natural Science Foundation, China (Grant No. 09JCYBJC01100), and the New Teacher Foundation of the Ministry of Education, China (Grant No. 200800561109).

Density functional theory study of NO2-sensing mechanisms of pure and Ti-doped WO3 (002) surfaces

Hu Ming(胡明)†, Wang Wei-Dan(王巍丹), Zeng Jing(曾晶), and Qin Yu-Xiang(秦玉香)   

  1. School of Electronics and Information Engineering, Tianjin University, Tianjin 300072, China
  • Received:2011-05-18 Revised:2011-06-07 Online:2011-10-15 Published:2011-10-15
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 60771019 and 60801018), Tianjin Key Research Program of Application Foundation and Advanced Technology, China (Grant No. 11JCZDJC15300), Tianjin Natural Science Foundation, China (Grant No. 09JCYBJC01100), and the New Teacher Foundation of the Ministry of Education, China (Grant No. 200800561109).

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摘要： Density functional theory (DFT) calculations are employed to explore the NO2-sensing mechanisms of pure and Ti-doped WO3 (002) surfaces. When Ti is doped into the WO3 surface, two substitution models are considered: substitution of Ti for W6c and substitution of Ti for W5c. The results reveal that substitution of Ti for 5-fold W forms a stable doping structure, and doping induces some new electronic states in the band gap, which may lead to changes in the surface properties. Four top adsorption models of NO2 on pure and Ti-doped WO3 (002) surfaces are investigated: adsorptions on 5-fold W (Ti), on 6-fold W, on bridging oxygen, and on plane oxygen. The most stable and likely NO2 adsorption structures are both N-end oriented to the surface bridge oxygen O1c site. By comparing the adsorption energy and the electronic population, it is found that Ti doping can enhance the adsorption of NO2, which theoretically proves the experimental observation that Ti doping can greatly increase the WO3 gas sensor sensitivity to NO2 gas.

Abstract: Density functional theory (DFT) calculations are employed to explore the NO2-sensing mechanisms of pure and Ti-doped WO3 (002) surfaces. When Ti is doped into the WO3 surface, two substitution models are considered: substitution of Ti for W6c and substitution of Ti for W5c. The results reveal that substitution of Ti for 5-fold W forms a stable doping structure, and doping induces some new electronic states in the band gap, which may lead to changes in the surface properties. Four top adsorption models of NO2 on pure and Ti-doped WO3 (002) surfaces are investigated: adsorptions on 5-fold W (Ti), on 6-fold W, on bridging oxygen, and on plane oxygen. The most stable and likely NO2 adsorption structures are both N-end oriented to the surface bridge oxygen O1c site. By comparing the adsorption energy and the electronic population, it is found that Ti doping can enhance the adsorption of NO2, which theoretically proves the experimental observation that Ti doping can greatly increase the WO3 gas sensor sensitivity to NO2 gas.

Key words: adsorption, Ti doping, NO2-sensing, density functional theory

中图分类号:  (Ab initio methods)

  • 21.60.De
21.60.Jz (Nuclear Density Functional Theory and extensions (includes Hartree-Fock and random-phase approximations)) 31.10.+z (Theory of electronic structure, electronic transitions, and chemical binding) 07.07.Df (Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing)