کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
149036 456426 2013 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Enhanced solar photocatalytic activity of TiO2 by selenium(IV) ion-doping: Characterization and DFT modeling of the surface
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Enhanced solar photocatalytic activity of TiO2 by selenium(IV) ion-doping: Characterization and DFT modeling of the surface
چکیده انگلیسی

TiO2 was doped with Se(IV) ions to obtain a visible light active photocatalyst with high photocatalytic activity. In order to characterize and describe the effect of Se(IV)-doping on the electronic and structural properties of TiO2, a combination of experimental structural methods and DFT calculations were used. A series of Se(IV)-doped photocatalysts with different Se(IV) contents were prepared by an incipient wet impregnation method, followed by calcination at 623, 723 and 823 K for 1 h, 3 h and 5 h. The Se(IV)-doped photocatalysts were characterized by XRD, XPS, UV-DRS, FESEM, EDX, HR-TEM and surface area (BET) measurements. A high visible light absorption band from 420 nm extending up to 650 nm in the UV-DRS was obtained. The photocatalytic activity of the Se(IV)-doped TiO2 photocatalyst was also determined by investigating the kinetics of the photocatalytic degradation of 4-nitrophenol under both UV-A and sunlight irradiation. Se(IV)-doped TiO2 enhanced the degradation rate of 4-NP. It also exhibited substantial photocatalytic activity under direct sunlight irradiation. In the computational part of the study, neutral, stoichiometric clusters Ti7O18H8 and Ti25O55H10 cut from the anatase bulk structure and two new models for the Se(IV)-doped TiO2 were developed. The DFT calculations were carried out by the hybrid B3LYP functional, by using double-zeta, LanL2DZ basis set. The experimental results combined with DFT calculations indicated that Se(IV)-doping of TiO2 enhances the visible-light photocatalytic activity by the introduction of additional electronic states originating from the Se 3p orbitals in the band gap.

Figure optionsDownload as PowerPoint slideHighlights
► TiO2 was doped with selenium(IV) ions.
► A high visible light absorption band from 420 nm extending up to 650 nm was obtained.
► Se(IV)-doping modified the photocatalytic activity of TiO2.
► DFT calculations were performed for the undoped and Se(IV)-doped cluster models.
► Se(IV)-doped TiO2 has additional mid-gap levels originating from Se 3p orbitals in the band-gap.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Engineering Journal - Volume 214, 1 January 2013, Pages 34–44
نویسندگان
, , ,