Manipulation of surface plasmon resonance for high photocatalytic activity of Ag-Bi2WO6 hetero-architecture

The plasmonic photocatalyst of Ag-Bi2WO6 was employed to investigate the effect of surface plasmon resonance (SPR) on the visible-light photocatalytic activity. Generally, it is accepted that metal nanoparticles as electron traps on the surface of semiconductor photocatalyst can effectively inhibit the recombination of photo-generated electron-hole pairs, provide more active sites and thereby enhance the photocatalytic activity. Nevertheless, SPR effect confirmed in Ag-Bi2WO6 plays an important role in the photoreaction enhancement in the meantime. In this case, a facile and more efficient method was introduced to synthesize Ag-Bi2WO6 hetero-architecture on basis of an ascorbic-acid-assisted route. The results and analysis show that a optimize photocatalytic efficiency can be achieved by elaborately manipulating SPR effect. For instance, the highest photocatalytic efficiency of 96.46% after 150 min visible-light irradiation was obtained as the molar ratio of Bi2WO6:Ag is 10:2, which suggest that it would be a promising candidate for photo-catalysis application. Eventually, a possible mechanism for the formation of Ag-Bi2WO6 hetero-architecture and its enhanced photocatalytic activity was proposed and discussed.