摘要
A series of heterojunction Ag2O/AgI photocatalysts with different Ag2O contents were successfully prepared though a facile two-step precipitation process at room temperature. The as-synthesized samples were measured in detail by XRD, EDS, XPS, SEM and DRS. The results showed that pherical Ag2O nanoparticles with diameter about 100-300 nm were uniformly distributed on the surface of Agl leading to the formation of Ag2O/Agl heterojunction. The photocatalytic activities of the obtained photocatalysts were evaluated by photocatalytic degradation of Rhodamine B (RhB) under visible light irradiation. The Ag2O/AgI with molar ratio of 1:1 showed the highest photocatalytic activities compared to the pure Ag2O and AgI with almost all RhB decomposed in 25 min. During photocatalytic process the visible light induced photogenerated electrons can be captured by Ag+ ions on the surface lattice of heterojunction to form plasmonic Ag nanoparticles, which may promote the interfacial charge transfer. The enhanced photocatalytic activity was then largely attributed to the synergetic effects of heterojunction Ag2O/AgI/Ag and the efficient separation of photogenerated electron hole pairs. This research may provide a novel Ag2O/AgI heterojunction with assistant of plasmonic Ag NPs to generate efficient, stable, and recyclable visible-light-driven plasmonic photocatalysts. The photocatalytic reaction kinetics and possible photo catalytic mechanism for this highly efficient photocatalysts were also proposed.