Plasmon enhanced visible light photocatalytic activity of ternary Ag2Mo2O7@AgBr-Ag rod-like heterostructures

In this work, a three-component system, Ag2Mo2O7@AgBr-Ag, has been successfully prepared through an in situ ion exchange reaction between Ag2Mo2O7 rods and Br-, followed by visible light irradiation. Using the as-prepared samples as photocatalysts, the visible light photocatalytic activity for degrading organic dyes, including methylene blue (MB) and Rhodamine B (RhB), is examined systematically. Among Ag2Mo2O7, Ag2Mo2O7/Ag, Ag2Mo2O7@AgBr, AgBr-Ag and Ag2Mo2O7@AgBr-Ag, the three-component Ag2Mo2O7@AgBr-Ag heterostructured photocatalyst is demonstrated to be superior compared to the others for dye photodegradation. The enhancements in visible light absorption and photocatalytic activity are ascribed to the synergistic effects originating from the surface plasmon resonance (SPR) of the Ag nanoparticles (NPs) and the cascade energy transfer for the effective separation of photogenerated carriers. Radical-trapping experiments demonstrate that holes (h(+)) are the major reactive species accounting for the degradation of MB and RhB molecules. Furthermore, five cycle tests indicate that the three-component hybrid photocatalyst Ag2Mo2O7@AgBr-Ag is highly stable and can be used repeatedly. Therefore, the Ag2Mo2O7@AgBr-Ag ternary heterostructures may be a promising candidate for use as a visible light photocatalyst for degrading organic contaminants in the near future.