University Chemistry ›› 2016, Vol. 31 ›› Issue (6): 72-79.doi: 10.3866/PKU.DXHX201510022

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Relationship between Photoelectron Lifetime and Dielectric Constant and Its Effect on the Photocatalysis

Ze-Dong LIN,Yu-Hua DAI*(),Ke-Xin LI*()   

  • Published:2016-06-29
  • Contact: Yu-Hua DAI,Ke-Xin LI;


In this article, the relationship equation between the photoelectron lifetime of the conduction band of photocatalyst and the dielectric constant of photocatalyst is derived. According to the photocatalytic mechanism and the derived equation, the relationship between the photocatalytic and the dielectric constant of the photocatalyst is elucidated as follows: the larger dielectric constant of the photocatalyst, the longer the photoelectron lifetime. Consequently, the transition of the photoelectrons from conduction band to the valence band to combine with the holes becomes harder through the stimulated emission and spontaneous emission, facilitating effective production of hydroxyl free radicals via the sufficient oxidation of hydroxyl ion and water by the holes occurring on the surface of photocatalyst.

Key words: Effect of photocatalysis, Photoelectron lifetime, Dielectric constant