Highly effective and stable Ag3PO4/WO3 photocatalysts for visible light degradation of organic dyes

• DOI: 10.1016/j.molcata.2014.04.010
• Publication Date: 2014-04-19T13:47:45Z
• Authors: Jiqiao Zhang; Kai Yu; Yifei Yu; Lan-Lan Lou; Zequn Yang; Junwei Yang; Shuangxi Liu
• Keywords: Degradation; Methyl orange; Rhodamine B; Visible spectrum

Abstract The Ag 3 PO 4 /WO 3 composites were prepared through a deposition–precipitation method and characterized by XRD, SEM, and DR UV–vis. These photocatalysts were evaluated in the degradation of rhodamine B (RhB) and methyl orange (MO) under visible light irradiation ( λ > 420 nm), and the synergistic effect of Ag 3 PO 4 and WO 3 was confirmed by notably higher photocatalytic activity compared to pure Ag 3 PO 4 and WO 3 catalysts. The effect of Ag 3 PO 4 :WO 3 ratio on the catalytic activity was systemically studied and the catalyst AW 6/4 was found to exhibit the highest catalytic activity. The degradation rates of RhB and MO could reach up to 97% under visible light irradiation for 6 min and 35 min, respectively. Moreover, the Ag 3 PO 4 /WO 3 photocatalysts showed higher recyclability than pure Ag 3 PO 4 catalyst and could be recycled five runs in the degradation of RhB without any loss in the activity. The characterization of used catalysts proved that Ag 3 PO 4 was effectively protected and much less metallic Ag was formed on the surface of Ag 3 PO 4 /WO 3 catalyst. The improvement of photocatalytic activity and stability is mainly attributed to the highly effective separation of photogenerated electron–hole pairs and special transfer pathway of electrons and holes in Ag 3 PO 4 /WO 3 composites.