Facile Synthesis of the Novel Ag3VO4/AgBr/Ag Plasmonic Photocatalyst with Enhanced Photocatalytic Activity and Stability

A novel ternary plasmonic Ag3VO4/AgBr/Ag hybrid photocatalyst was successfully fabricated via an in situ anion-exchange reaction between Ag3VO4 and KBr, followed by light reduction. The obtained samples were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, UV–visible diffuse-reflectance spectroscopy (UV–vis DRS), and X-ray photoelectron spectroscopy. The photocatalytic activities of obtained photocatalysts were measured by the degradation of Rhodamine B and methylene blue under visible-light irradiation (λ ≥ 400 nm). As-prepared Ag3VO4/AgBr/Ag plasmonic photocatalysts exhibit wide absorption in the visible-light region and display superior visible-light-driven photocatalytic activities in degradation of organic contamination compared with pristine Ag3VO4, Ag3VO4/AgBr, and AgBr/Ag. This enhanced photocatalytic activity is attributed to the synergistic effects between Ag3VO4/AgBr-based heterostructured semiconductor photocatalysis and the surface plasmon resonance (SPR) of Ag nanoparticles (NPs). On the basis of UV–vis DRS and valence band X-ray photoelectron spectroscopy, a possible mechanism of enhanced photocatalytic activity of Ag3VO4/AgBr/Ag is proposed; the vectorial electron transfer driven by the matching band potentials of AgBr and Ag3VO4 and the SPR of Ag NPs contribute to its high photocatalytic activity and the improved stability. Therefore, the present study provides helpful insight into the design of novel and highly efficient visible-light photocatalysts in the future.