Physical and optical properties of Ag3PO4 decorated TiO2 based nanostructures

The pursuit of materials with activity under the visible-light irradiation lead to important efforts in the photo-catalysts development, among which the fabrication of heterojunctions has attracted greater attention. This work investigated the microstructure and optical properties of two titania-based nanomaterials decorated with Ag3PO4 nanoparticles. Trititanate nanotubes (TTNT) and titania nanorods (TNR) were prepared by alkaline hydrothermal synthesis with further deposition of Ag3PO4 nanoparticles by in situ precipitation route. The characterization of the materials was carried out by HRTEM, STEM-EDS, XRD, XPS, and DRS. The results successfully demonstrated the growth of Ag3PO4 nanoparticles in the order of 5 nm on the surface of the titania nanomaterials, with a similar displacement of the band-gap equivalent wavelength (lambda(eq)) measured by DRS from 375 nm (undecorated) to 400 nm (decorated). The synthesized materials appeared to have higher uniformity in the photoactivation properties than those previous reported, having the physical characterization provided a high detailing of the materials microstructure. Comparative data has suggested the saturation of the TNRs surface in a direct correlation to its lowest superficial area, as well as the greater absorbance behaviour of the material. Furthermore, the surface analysis determined the occurrence of phosphate grafting at both of the heterojunctions, with no further electronic transitions have being identified or associated with the grafted phosphates groups.