Chemical Journal of Chinese Universities ›› 2020, Vol. 41 ›› Issue (3): 538-547.doi: 10.7503/cjcu20190467

• Physical Chemistry • Previous Articles     Next Articles

Excellent Ultraviolet Photocatalytic Efficiency of Mg 2+ Doped ZnO and Analysis on Its Synergetic Effect

ZHAO Peng,ZHANG Jinteng,LIN Yanhong   

  1. College of Chemistry, Jilin University, Changchun 130012, China
  • Received:2019-08-27 Online:2020-02-26 Published:2020-01-15
  • Contact: Yanhong LIN
  • Supported by:
    † Supported by the National Natural Science Foundation of China(Nos.21872063);† Supported by the National Natural Science Foundation of China(Nos.51572106);† Supported by the National Natural Science Foundation of China(Nos.21773086)

Abstract:

A series of Mg-doped ZnO samples were synthesized via a facile chemical precipitation method. Mg 2+ was effectively doped into the lattice of ZnO and MgO particles formed on the surface of ZnO when the Mg doping content exceeded 5%. Under the combined action of Mg 2+ and MgO insulators, the degradation rate of RhB over 10%Mg-ZnO photocatalyst was 81.3% in 5 min under ultraviolet light and the degradation rate constant was 0.3271 min -1, which was 3.42 times that of pure ZnO(0.0957 min -1). The transient photovoltage(TPV) and the contact potential difference(ΔCPD) measurements directly demonstrated that the incorporation of Mg 2+ decreased the work function of ZnO and increased the number of electrons in the conduction band, thus the separation efficiency of photogenerated electrons and holes can be improved. The surface photocurrent(SPC) and the Cr(Ⅵ) reduction experiments showed that the formation of MgO insulating particles inhibited the “reverse” transmission of photogenerated electrons in ZnO, which prolonged the recombination time of electrons and holes, thus indirectly improved the utilization of photogenerated holes. This work provides a new idea for the design of highly efficient photocatalytic materials.

Key words: Mg doped ZnO, Photocatalysis, Synergetic effect, Photogenerated charges behavior

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