Optical Properties and Photoactivity of The Pigmentary TiO2 Doped with P2O5, K2O, Al2O3 and Sb2O3

Abstract

The influence of the increasing content of antimony calculated to Sb2O3 (0.08–0.57 mol%) with the constant amount of the other additives (calculated to P2O5, K2O, Al2O3) on the optical properties and photostability of doped rutile has been investigated. The properties of the obtained TiO2-PKAlSb samples were compared to the commercial TiO2-PKAl composition. The starting material was the concentrated suspension of technical-grade hydrated titanium dioxide (HTD). The dopant agents' solutions were introduced to HTD. Prepared samples were calcined with gradually increasing process temperature. The XRD analysis was used to determine the rutile content in the TiO2 samples. Optical properties of modified titanium dioxide have been determined spectrophotometrically by measuring the colour in the white (brightness, white tone) and grey system (relative lightening power, grey tone). Photostability was characterized by the white lead-glycerin test with UV-Vis light. It was observed that with the increasing content of antimony in rutile TiO2, doped with phosphates, potassium and aluminium, the brightness and grey tone were increasing but white tone decreased. The changes of the relative lightening power values were insignificant. Comparing the samples of TiO2-PKAlSb with the TiO2-PKAl composition it was observed that titanium dioxide doped with antimony had better white and grey tone. The increasing Sb2O3 content in the TiO2 caused the improvement of the photostability.