Sulfur/Gadolinium-Codoped TiO2Nanoparticles for Enhanced Visible-Light Photocatalytic Performance

Abstract

A series of S/Gd3+-codoped TiO2photocatalysts 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 TiO2under visible-light with varying concentrations of Gd3+ions in the host material. XRD and Raman results confirmed the existence of anatase phase TiO2with 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 TiO2showed significant visible-light induced photocatalytic activity towards Indigo Carmine dye compared with S-TiO2or commercial TiO2. TiO2-S/Gd3+(0.6% Gd3+) degraded the dye (ka= 5.6 × 10−2 min−1) completely in 50 min.