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A comparative study of physicochemical and photocatalytic properties of visible light responsive Fe, Gd and P single and tri-doped TiO2 nanomaterials

Adyani, S. M ; Sharif University of Technology | 2018

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  1. Type of Document: Article
  2. DOI: 10.1016/j.jre.2017.06.012
  3. Publisher: Chinese Society of Rare Earths , 2018
  4. Abstract:
  5. High performance Fe-Gd-P tri-doped TiO2 nanoparticles (1 at% for each dopant) were successfully synthesized by a modified sol–gel method. Various analytical and spectroscopic techniques were carried out to determine the physicochemical properties of the prepared samples, including XRD, EDX, FESEM, BET, FTIR, XPS, PL, EIS and UV–Vis diffuse reflectance spectroscopy. The photocatalytic activities of prepared samples were evaluated by photo degradation of methyl orange (MO) and 4-chlorophenol (4-CP) as model pollutants under visible light irradiation. Effects of each dopant on different properties of TiO2 nanoparticles were investigated. Results show that Gd and P doping enhances TiO2 surface textural properties by forming Ti–O–Gd and Ti–O–P bonds. It is found that Gd plays a superior role in increasing oxygen vacancies and organic species on TiO2 surface. Gd doping also facilitates transferring of the photo-induced charge carriers to the surface adsorbed species. The enhanced electronic band structure and visible light response, as well as high electron lifetime of Fe-Gd-P tri-doped sample is mainly attributed to Fe and Gd doping. The tri-doped TiO2 with rate constant of kapp = 1.28 × 10−2 min−1 for MO and kapp = 0.94 × 10−2 min−1 for 4-CP, shows the highest photodegradation rate among all samples including undoped and single doped samples. The improved photocatalytic performance of Fe-Gd-P tri-doped TiO2 is due to the synergistic effect of enhanced surface chemistry and textural properties, increased number of surface adsorbed hydroxyl groups and organic species, improved visible light absorption, increased lifetime of the photo-induced electron/hole pairs and boosted interfacial charge transfer. © 2017 Chinese Society of Rare Earths
  6. Keywords:
  7. Fe-Gd-P tri-doped TiO2 ; Photodegradation ; Rare earths ; Sol–gel synthesis ; Visible light response ; Azo dyes ; Charge transfer ; Doping (additives) ; Electromagnetic wave absorption ; Fourier transform infrared spectroscopy ; Gadolinium ; Light absorption ; Nanoparticles ; Oxygen vacancies ; Photocatalysis ; Rate constants ; Sol-gel process ; Sol-gels ; Surface chemistry ; Synthesis (chemical) ; Electronic band structure ; Interfacial charge transfer ; Photocatalytic activities ; Photocatalytic performance ; Sol - Gel synthesis ; Synergistic effect ; UV-Vis diffuse reflectance spectroscopy ; Visible-light response ; Light
  8. Source: Journal of Rare Earths ; Volume 36, Issue 1 , 2018 , Pages 72-85 ; 10020721 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/pii/S1002072117300704