A novel visible-light-driven photocatalyst Ag2O/AgI with highly enhanced photocatalytic performances

A series of heterojunction Ag 2 O/AgI photocatalysts with different Ag 2 O 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 Ag 2 O nanoparticles with diameter about 100–300 nm were uniformly distributed on the surface of AgI leading to the formation of Ag 2 O/AgI heterojunction. The photocatalytic activities of the obtained photocatalysts were evaluated by photocatalytic degradation of Rhodamine B (RhB) under visible light irradiation. The Ag 2 O/AgI with molar ratio of 1:1 showed the highest photocatalytic activities compared to the pure Ag 2 O 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 Ag 2 O/AgI/Ag and the efficient separation of photogenerated electron–hole pairs. This research may provide a novel Ag 2 O/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 photocatalytic mechanism for this highly efficient photocatalysts were also proposed.