Enhanced Solar Light Photocatalytic Activity of Ag Doped TiO 2 -Ag 3 PO 4 Composites.

Composites comprised of Ag ₃ PO ₄ and bare TiO ₂ (TiO ₂ @Ag ₃ PO ₄ ) or silver doped TiO ₂ (Ag@TiO ₂ -Ag ₃ PO ₄ ) have been synthesized by coupling sol-gel and precipitation methods. For the sake of comparison, also the bare components have been similarly prepared. All the samples have been characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), photoelectrochemical measurements, and specific surface area (SSA) analysis. The optoelectronic and structural features of the samples have been related to their photocatalytic activity for the degradation of 4-nitrophenol under solar and UV light irradiation. Coupling Ag ₃ PO ₄ with silver doped TiO ₂ mitigates photocorrosion of the Ag ₃ PO ₄ counterpart, and remarkably improves the photocatalytic activity under solar light irradiation with respect to the components, to the TiO ₂ -Ag ₃ PO ₄ sample, and to the benchmark TiO ₂ Evonik P25. These features open the route to future applications of this material in the field of environmental remediation.