Chemical Research in Chinese Universities ›› 2017, Vol. 33 ›› Issue (2): 255-260.doi: 10.1007/s40242-017-6378-5

• Articles • Previous Articles     Next Articles

Density Functional Theory Study of CO2 and H2O Adsorption on a Monoclinic WO3(001) Surface

LIU Li1, LIN Maohai1, LIU Zhongbo2, SUN Honggang3, ZHAO Xian3   

  1. 1. Faculty of Light Industry, Qilu University of Technology, Jinan 250353, P. R. China;
    2. School of Science, Shandong Jiaotong University, Jinan 250357, P. R. China;
    3. State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P. R. China
  • Received:2016-09-12 Revised:2016-11-04 Online:2017-04-01 Published:2017-01-09
  • Contact: LIU Li,E-mail:liuli_1636@qlu.edu.cn E-mail:liuli_1636@qlu.edu.cn
  • Supported by:

    Supported by the National Natural Science Foundation of China(No.11447151) and the Natural Science Foundation of Shandong Province, China(No.ZR2014BP008).

Abstract:

Understanding the interaction of WO3 with CO2 and H2O is vital for clarifying its role in the photocatalytic reduction of CO2. In this study, we employed density functional theory to investigate the interaction of CO2 and H2O with both perfect and defective monoclinic WO3(001) surfaces. The interactions of co-adsorbed CO2 and H2O were also studied. The major finding is that the presence of oxygen vacancies and co-adsorbed CO2 or H2O can significantly increase the stability of CO2 and H2O on the WO3(001) surface. A defective WO3(001) surface is more capable of adsorbing a single CO2 or H2O molecule than a perfect WO3(001) surface, and H2O adsorbed onto a defective WO3(001) surface spontaneously dissociates into a hydrogen atom and a hydroxy group. The presence of co-adsorbed H2O can increase the stability of CO2 on the WO3(001) surface, while the presence of the co-adsorbed CO2 can increase the stability of H2O on WO3(001) surface. The analysis of the bonding mechanisms shows that the charge redistribution between the adsorbate and the WO3(001) surface containing oxygen vacancies and co-adsorbed CO2 or H2O is stronger than that between the adsorbate and the perfect WO3(001) surface; thus, adsorption energy is higher in the former case. The results will be useful for designing WO3 photocatalysts, as well as for an atomistic-level understanding of the photocatalytic reduction of CO2.

Key words: Density functional theory, Carbon dioxide, Water, Adsorption, Tungsten trioxide, Photocatalysis