Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (4): 729-737.doi: 10.3866/PKU.WHXB201402243

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Synthesis, Regeneration and Photocatalytic Activity under Visible-Light Irradiation of Ag/Ag3PO4/g-C3N4 Hybrid Photocatalysts

LIU Jian-Xin, WANG Yun-Fang, WANG Ya-Wen, FAN Cai-Mei   

  1. Institute of Clean Technique for Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China
  • Received:2013-12-09 Revised:2014-02-24 Published:2014-03-31
  • Contact: WANG Yun-Fang
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21206105, 21176168).


Ag/Ag3PO4/g-C3N4 (g denotes graphitic) was synthesized via an anion-exchange precipitation method, and its photocatalytic activity under visible light and regeneration with H2O2 and NaNH4HPO4 were investigated. The structural characteristics were analyzed using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), ultraviolet-visible (UV-Vis) absorption spectroscopy, and X-ray photoelectron spectroscopy (XPS). The XRD results showed that the structure of the regenerated catalyst was unchanged. The FESEM and UV-Vis absorption spectroscopy results showed that the Ag/Ag3PO4/g-C3N4 catalyst was composed of Ag3PO4 and g-C3N4. XPS showed that a small amount of Ag particles were present on the catalyst surface. The photocatalytic activity was evaluated using phenol degradation under visible light (λ>420 nm) and the photocatalytic mechanism was discussed based on the active species during the photocatalytic process and the band structure. Experimental studies showed that the photocatalytic activity of the as-prepared Ag/Ag3PO4/g-C3N4 was higher than those of pure Ag3PO4 and g-C3N4. The high photocatalytic performance of the Ag/Ag3PO4/g-C3N4 composite can be attributed to the synergistic effect of Ag3PO4, g-C3N4, and a small amount of Ag0. Regeneration using H2O2 and NaNH4HPO4? 4H2O fully restored the photoactivity of the catalyst, showing that this green regeneration method could make Ag/Ag3PO4/g-C3N4 an environmentally friendly catalyst for practical applications.

Key words: Silver phosphate, g-C3N4, Metallic silver, Catalyst regeneration, Phenol, Photocatalysis