Sulfur/gadolinium-codoped TiOnanoparticles for enhanced visible-light photocatalytic performance

Abstract

A series of S/Gd3+-codoped TiOphotocatalysts 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 TiOunder visible-light with varying concentrations of Gd3+ ions in the host material. XRD and Raman results confirmed the existence of anatase phase TiOwith 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 TiOshowed significant visible-light induced photocatalytic activity towards Indigo Carmine dye compared with S-TiOor commercial TiO TiOS/Gd3+ (0.6% Gd3+) degraded the dye (k a = 5.6 × 10-2 min-1) completely in 50 min. © 2014 Eric S. Agorku et al.