Highly efficient visible-light-induced photocatalytic activity of nanostructured AgI/TiO2 photocatalyst

Nanostructured AgI/TiO2 photocatalyst was synthesized by a feasible approach with AgNO3, LiI, and Ti(OBu)(4) and characterized by X-ray diffraction, transmission electron microscopy, angle-dependent X-ray photoelectron spectroscopy, diffusive reflectance UV-vis spectroscopy, Raman spectroscopy, photoluminescence, and the Brunauer-Emmett-Teller technique. The results of characterization reveal that the nanostructured AgI/TiO2 has a novel core/shell/shell nanostructure of AgI/Ag-12/TiO2. Compared with TiO2 (P25) supported Aul, the formation of the nanostructure results in substantial shifting of the absorption edge of AgI to red, enhancement of the absorption intensity, and the appearance of a strong tail absorption above 490 nm, which is assigned to the absorption of 1, and Ag. Photocatalytic tests show that the nanostructured AgI/TiO2 photocatalyst exhibited very high visible-light-induced photocatalytic activity for the photodegradation of crystal violet and 4-chlorophenol, which is 4 and 6 times higher than that of P25 fitania supported Agl, respectively. The highly efficient visible-light-induced photocatalytic activity of the nanostructured AgI/TiO2 is attributed to its strong absorption in the visible region and low recombination rate of the electron-hole pairdue to the synergetic effect among the components of AgI, Ag, I-2, and TiO2 ill the nanostructured AgI/TiO2.