Synthesis of novel CaCO3/Ag2CO3/Ag I/Ag plasmonic photocatalyst with enhanced visible light photocatalytic activity.

In this work, novel Ca CO3/Ag2CO3/Ag I/Ag plasmonic photocatalysts were successfully synthesized by a two-step in situ ion exchange process and their photocatalytic properties were studied. The morphology, crystal structure and optical properties of the as-prepared Ca CO3/Ag2CO3/Ag I/Ag nanocomposites were characterized by transmission electron microscopy(TEM), XRay diffraction(XRD), and UV-vis diffuse reflectance spectroscopy. The photocatalytic activity of the obtained nanocomposites was evaluated by the photodegradation of methyl orange(MO) under visible light irradiation. It was found that the as-prepared Ca CO3/Ag2CO3/Ag I/Ag plasmonic photocatalyst exhibits high visible light photocatalytic activity. With an optimized composition, MO dye can be decomposed by more than 94% within 15 min under visible light irradiation. Moreover, the photocatalytic stability could be greatly improved upon the addition of Na2CO3 into the photocatalytic system. From the proposed photocatalytic mechanism, the strong surface plasmon resonance effect of Ag nanoparticles and the efficient separation of photogenerated electrons and holes can effectively enhance the photocatalytic performance of the Ca CO3/Ag2CO3/ Ag I/Ag composites.