Pigmentary properties of rutile TiO2 modified with cerium, phosphorus, potassium, and aluminium

AbstractThe influence of different modifiers, phosphorus, potassium, aluminium, and cerium on the pigmentary properties of TiO2 was studied. The phase composition and distribution of modifiers in prepared TiO2 products was investigated using XRD analysis, the selective leaching method, and ICP-AES technique. The optical properties, photoactivity, morphology, and surface area of modified TiO2 were determined by spectrophotometric, fluorescent, SEM, and BET measurements. The research was directed towards obtaining a pigmentary TiO2 with the highest possible photostability. It was found that the final calcination temperature, at which the anatase-rutile transformation rate was > 97 %, depended on the kind and amount of the modifiers introduced into hydrated titanium dioxide. In comparing the colour of TiO2 products modified with Ce, it was found that the addition of K to the TiO2 series caused an increase in all the optical properties examined. The presence of K and Al in TiO2 modified with Ce resulted in decreased photocatalytic activity. The photostability of TiO2 modified with Ce and K improved with an increase in P2O5 content. The highest photostability was measured for the TiO2-CePKAl series. It was concluded that the differences in both the optical properties and photoactivity of TiO2 depended on its phase composition and the distribution of modifiers in the products obtained.