Chinese Journal of Applied Chemistry ›› 2020, Vol. 37 ›› Issue (9): 1030-1037.DOI: 10.11944/j.issn.1000-0518.2020.09.200047

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Preparation of Ag3PO4 Quantum Dots/g-C3N4 Nanosheet Composite Photocatalysts and Its Activity for Selective Oxidation of Benzyl Alcohol

HUANG Jieying, LIU Jianjun*, ZUO Shengli, HAN Wenjing, YU Yingchun   

  1. College of Chemistry,Beijing University of Chemical Technology,Beijing 100029,China
  • Received:2020-02-20 Published:2020-09-01 Online:2020-09-09
  • Contact: LIU Jianjun, associate professor; Tel:010-64431056;; Research interests:photocatalysis
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.21876008)

Abstract: In this paper, a series of Ag3PO4 quantum dots/g-C3N4 nanosheet composite photocatalysts was prepared at room temperature for the first time with the ultrathin g-C3N4 nanosheet exfoliated by thermal oxidation as the support. The morphology, structure and optical properties of the photocatalysts were characterized by transmission electron microscopy(TEM), high resolution TEM(HRTEM), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy analysis (FT-IR), ultraviolet-visible diffuse-reflectance spectroscopy (UV-Vis DRS), photoluminescence spectroscopy (PL) techniques. The photocatalytic selective oxidation of benzyl alcohol was investigated. The results show that quantum dots of well-crystallized Ag3PO4 with the particle size of 3~5 nm are homogeneously dispersed on the g-C3N4 nanosheet. For the photocatalysts with the mass ratio of 0.6 Ag3PO4 to g-C3N4 in acetonitrile, the maximum conversion of benzyl alcohol is 32.1%, and the highest selectivity of benzaldehyde is 90%. The results of active species capture experiment show that the main active species of photogenerated hole are responsible for the selective oxidation. The results of energy band calculation show that the composite catalyst has a suitable oxidation potential for benzyl alcohol into benzaldehyde.

Key words: thermal oxidation, Ag3PO4 quantum dots, photocatalysis, benzyl alcohol oxidation, photogenerated hole