Preparation of novel Bi4O5I2/Ag3PO4 with enhanced visible-light photocatalytic activities

A series of different ratios of Bi4O5I2/Ag3PO4 (abbreviated as Bi(4)AP) composite photocatalysts were synthesized and characterized through XRD, FT-IR, SEM, EDS and UV-vis DRS analysis, respectively. The photocatalytic properties of as-prepared samples were evaluated by photodegradation of Rhodamine B (RhB) in the visible range. The results showed that the photocatalytic activity of the composite photocatalyst was higher than that of pure Bi4O5I2 or Ag3PO4. Among the as-prepared samples, the photodegradation ability of Bi(4)AP-3 was more remarkable, and RhB underwent complete degradation in 60 min under optimal conditions (T = 308 K, pH = 9). Trapping experiments proved that photogenerated holes (h(+)) were the main active substance in the photocatalytic process, superoxide radicals (center dot O-2(-)) and hydroxyl radicals (center dot OH) also played an important role. Furthermore, the photocatalytic mechanism was also proposed.