Acta Phys. -Chim. Sin. ›› 2016, Vol. 32 ›› Issue (10): 2511-2517.doi: 10.3866/PKU.WHXB201607131

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Theoretical Study of the Interfacial Structure and Properties of a CdS/FeP Composite Photocatalyst

Zong-Yan ZHAO1,2,*(),Fan TIAN1   

  1. 1 Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, P. R. China
    2 Yunnan Key Laboratory of Micro/Nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming 650504, P. R. China
  • Received:2016-04-19 Published:2016-09-30
  • Contact: Zong-Yan ZHAO E-mail:zzy@kmust.edu.cn
  • Supported by:
    The project was supported by the National Natural Science Foundation of China(21473082);and 18th Yunnan Province Young Academic and Technical Leaders Reserve Talent Project(2015HB015)

Abstract:

An effective method for improving the performance of a photocatalyst is to construct a suitable hetero-/homo-structure. This strategy can also lead to improvements in the stability of the photocatalysts that suffer with photo-corrosion (such as CdS). The preparation of CdS-based composite photocatalysts has therefore been widely studied. Unfortunately, however, some of the fundamental and more significant aspects of this strategy still need to be evaluated in greater detail. In this study, we have evaluated the interfacial microstructure and properties of a CdS/FeP composite photocatalyst with a hetero-structure using a series of the firstprinciples calculations. The results revealed that the electronic structure of the interface model exhibited different features compared with the bulk and surface models, because of the partially saturated dangling bonds. However, several obvious interfacial states were observed. At the interface of the CdS/FeP hetero-structure, the energy bands of CdS and FeP were relatively down-shifted, whereas the energy band of FeP was inserted below the conduction band of CdS. Furthermore, the direction of the built-in electric field of the hetero-structure projected out from the FeP layer towards the CdS layer under the equilibrium conditions. The photo-generated electron-hole pairs were therefore spatially separated by the CdS/FeP interface, which was favorable for improving the photocatalytic performance. The construction of a CdS/FeP hetero-structure can also lead to further improvements in the absorption properties of CdS in the visible-light region. The results of this study have provided mechanical explanations and theoretical support for the construction of highly efficient composite photocatalyst with hetero-structures.

Key words: Photocatalysis, Cadmium sulfide, Hetero-structure, Interfacial micro-structure, Interfacial property, Density functional theory calculation

MSC2000: 

  • O647