Chinese Journal of Catalysis ›› 2020, Vol. 41 ›› Issue (8): 1230-1239.DOI: 10.1016/S1872-2067(20)63531-8

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Construction of nitrogen and phosphorus co-doped graphene quantum dots/Bi5O7I composites for accelerated charge separation and enhanced photocatalytic degradation performance

Kai Lia, Mengxia Jia, Rong Chenb, Qi Jiangb, Jiexiang Xiaa, Huaming Lia   

  1. a School of Chemistry and Chemical Engineering, Institute for Energy Research, Jiangsu University, Zhenjiang 212013, Jiangsu, China;
    b School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, China
  • Received:2019-11-02 Revised:2019-12-18 Online:2020-08-18 Published:2020-08-08
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (21676128 and 21576123), Jiangsu University Scientific Research Funding (11JDG0146), and the Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX17_1791).

Abstract: Nitrogen and phosphorus co-doped graphene quantum dot-modified Bi5O7I (NPG/Bi5O7I) nanorods were fabricated via a simple solvothermal method. The morphology, structure, and optical properties of the as-prepared samples were investigated by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), and diffused reflectance spectroscopy. The photocatalytic performance was estimated by degrading the broad-spectrum antibiotics tetracycline and enrofloxacin under visible light irradiation. The photodegradation activity of Bi5O7I improved after its surface was modified with NPGs, which was attributed to an increase in the photogenerated charge transport rate and a decrease in the electron-hole pair recombination efficiency. From the electron spin resonance spectra, XPS valence band data, and free radical trapping experiment results, the main active substances involved in the photocatalytic degradation process were determined to be photogenerated holes and superoxide radicals. A possible photocatalytic degradation mechanism for NPG/Bi5O7I nanorods was proposed.

Key words: Bi5O7I, N,P co-doped graphene quantum dots, Photocatalysis, Ionic liquid, Charge separation