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Journal of Nanomaterials
Volume 2014, Article ID 289150, 11 pages
Research Article

Sulfur/Gadolinium-Codoped TiO2 Nanoparticles for Enhanced Visible-Light Photocatalytic Performance

1Department of Applied Chemistry, University of Johannesburg, P.O. Box 17011, Doornfontein Campus, Johannesburg 2028, South Africa
2Nanotechnology and Application Centre, University of Allahabad, Allahabad 211002, India

Received 4 October 2013; Revised 20 November 2013; Accepted 4 December 2013; Published 6 April 2014

Academic Editor: Godwin Ayoko

Copyright © 2014 Eric S. Agorku et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A series of S/Gd3+-codoped TiO2 photocatalysts were synthesized by a modified sol-gel method. The materials were characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV-visible diffuse reflectance spectroscopy, scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM)/energy-dispersive spectroscopy (EDS). Laboratory experiments with Indigo Carmine chosen as a model for organic pollutants were used to evaluate the photocatalytic performance of S/Gd3+-codoped TiO2 under visible-light with varying concentrations of Gd3+ ions in the host material. XRD and Raman results confirmed the existence of anatase phase TiO2 with particle size ranging from 5 to 12 nm. Codoping has exerted a great influence on the optical responses along with red shift in the absorption edge. S/Gd3+-codoped TiO2 showed significant visible-light induced photocatalytic activity towards Indigo Carmine dye compared with S-TiO2 or commercial TiO2. TiO2-S/Gd3+ (0.6% Gd3+) degraded the dye ( = 5.6 × 10−2 min−1) completely in 50 min.