An effective strategy for boosting photoinduced charge separation of Ag3PO4 by BiVO4 with enhanced visible light photodegradation efficiency for levofloxacin and methylene blue.

Abstract

In this paper, a Z-scheme Ag3PO4/BiVO4 photocatalyst was successfully prepared by precipitation-deposition method. The Ag3PO4/BiVO4 composite exhibited enhanced photocatalytic activity and recyclability for levofloxacin and methylene blue degradation under visible light irradiation. In the Ag3PO4/BiVO4-0.4 system, up to 92.44% of the levofloxacin molecules can be decomposed within 180min and the photocatalytic degradation efficiency can maintain at 92.02% for methylene blue after recycled for 5 times. The enhanced photocatalytic activity of Ag3PO4/BiVO4 heterojunctions could be mainly attributed to the fabrication of hetero-structure between BiVO4 and Ag3PO4. The photogenerated electron-hole pair separation was effectively enhanced based on the photocurrent, electro-chemical impedance spectra and photoluminescence data. Furthermore, the electrons transfer from photoinduced BiVO4 to Ag3PO4 and the visible light harvesting efficiencies were significantly increased due to the BiVO4 hybridization. The ·OH was the main oxidative species in the Ag3PO4/BiVO4 system for the methylene blue decomposition. Finally, a purposed photocatalytic mechanism for methylene blue degradation was discussed in detail on the basis of experimental results.