Synthesis of Hollow BiVO4/Ag Composite Microspheres and Their Photocatalytic and Surface-Enhanced Raman Scattering Properties

Hollow BiVO4 microspheres are prepared in the presence of ethylenediaminetetraacetic acid (EDTA) through a hydrothermal method, and used as a template for the fabrication of Ag-nanoparticle-decorated BiVO4 (BiVO4/Ag) composite microspheres. The morphology and structure are characterized by transmission electron microscopy and scanning electron microscopy. It is found that EDTA plays an important role in the formation of the hollow microspheres, and the possible formation mechanism is discussed. UV/visible spectrometry analysis shows that the BiVO4/Ag composite microspheres exhibit a distinct surface plasmon absorption band compared with pure BiVO4 microspheres. The photocatalytic activities of the BiVO4/Ag composite microspheres are examined by studying the degradation of rhodamine6G (R6G) solutions under visible-light irradiation (>400nm). The results show clearly that the BiVO4/Ag composite microspheres possess a much higher photocatalytic activity than pure BiVO4 microspheres and P25. In addition, Raman analyses show that the BiVO4/Ag composite microspheres exhibit an excellent surface-enhanced Raman scattering (SERS) performance.