Impact of Ge 4+ ion as structural dopant of Ti 4+ in anatase: Crystallographic translation, photocatalytic behavior, and efficiency under UV and VIS irradiation

Abstract

Nanometric particles of germanium-doped TiO2 were prepared by homogeneous hydrolysis of TiOSO4 and GeCl4 in an aqueous solution using urea as the precipitation agent. Structural evolution during heating of these starting Ge-Ti oxide powders was studied by X-ray diffraction (XRD) and high-temperature X-ray powder diffraction (HTXRD). The morphology and microstructure changes were monitored by means of scanning electron microscopy (SEM), Raman and infrared spectroscopy (IR), specific surface area (BET), and porosity determination (BJH). The photocatalytic activity of all samples was determined by decomposition of Orange II dye under irradiation at 365nm and 400nm. Moderate doping with concentration upto value 2.05wt. positively influences azo dye degradation under UV and Vis light. Further improvement cannot be achieved by higher Ge doping. Effect of the annealing (200, 400, and 700C) on photocatalysis and other properties has been assessed. Copyright © 2012 Vclav tengl et al.