title: Enhanced photocatalytic activity for degrading Rhodamine B solution of commercial Degussa P25 TiO2 and its mechanisms.
abstract: In this paper, the Degussa P25 TiO(2) (P-TiO(2)) is modified by the post-treatment with the phosphorous acid, and the resulting samples are also characterized by X-ray Powder Diffraction (XRD), Raman spectra (Raman), Brunauer-Emmett-Teller (BET) surface area analyzer, Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectra (FT-IR), X-ray Photoelectron Spectroscopy (XPS), Ultraviolet-Visible Diffuse Reflectance Spectra (UV-vis DRS) and Surface Photovoltage Spectroscopy (SPS). The effects of surface-modification on the thermal stability and photocatalytic activity of the P-TiO(2) are investigated in detail. The results show that the surface-modification enhances the thermal stability of P-TiO(2), even still with a main anatase phase after thermal treatment at 900 degrees C, which is close related to the inhibition effects of the PO(4)(3-) groups on the surface mass diffusion as well as the directing connections of P-TiO(2) nanoparticles. Interestingly, the modified P-TiO(2) by thermal treatment at 700 and 800 degrees C can exhibit much higher photocatalytic activity than un-modified ones. The reasons for the activity enhancement are involved with the enhanced anatase thermal stability, consequently improving photoinduced charge separation rate, and still keeping large surface area and a certain amount of surface hydroxyl groups.
authors.affiliation: Key Laboratory of Functional Inorganic Materials Chemistry, Heilongjiang University, Ministry of Education, School of Chemistry and Materials Science, Harbin 150080, PR China.
authors.forename: Xu
authors.initials: X
authors.lastname: Qin
authors.forename: Liqiang
authors.initials: L
authors.lastname: Jing
authors.forename: Guohui
authors.initials: G
authors.lastname: Tian
authors.forename: Yichun
authors.initials: Y
authors.lastname: Qu
authors.forename: Yujie
authors.initials: Y
authors.lastname: Feng
mesh_terms: D002384:Catalysis; D006358:Hot Temperature; D055668:Photochemical Processes; D012235:Rhodamines / Q000737:chemistry* / Q000528:radiation effects; D012996:Solutions; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D012235:Rhodamines; D012996:Solutions; C009495:titanium dioxide; D014025:Titanium; C029773:rhodamine B