Ag/Ag3PO4-doped BiPO4 heterostructures and their photocatalytic applications under visible light irradiation

Y.-J. Chen, P.-J. Tseng, C.-W. Huang, C.-S. Tseng, T.H. Wu, C.-Y. Lai, M.-Y. Wu, Y.-W. Lin
National Changhua University of Education,
Taiwan

Keywords: BiPO4, Ag/Ag3PO4-doped BiPO4, visible light photocatalytic activity, degradation, disinfection

Summary:

Ag/Ag3PO4-doped BiPO4 (Ag/Ag3PO4/BiPO4) heterostructures were synthesized by the hydrothermal method combined with the sonochemical process. Powder X-ray diffractometry, UV–Vis diffuse reflectance spectroscopy, Raman spectroscopy, and transmission electron microscopy were used to characterize the heterostructures. The morphologies and optical properties of the heterostructures were determined to be drastically different from those of BiPO4. Ag/Ag3PO4/BiPO4 was used in the photocatalytic degradation of a dyestuff (methylene blue) and the disinfection of pathogens (Escherichia coli and Staphylococcus aureus) under visible light ( > 420 nm) irradiation, and it displayed considerably higher photocatalytic activity (>99% degradation and >99% disinfection within 20 min) than did pure BiPO4. This enhanced photocatalytic activity of the Ag/Ag3PO4/BiPO4 heterostructure can be attributed to the high separation efficiency and low recombination rate of photogenerated electron–hole pairs, as well as the Ag+ ions release under visible light irradiation. The possible mechanism underlying the enhanced photocatalytic activities of these heterostructures is also provided.