Structure, Morphology, and Photocatalytic Activity of Titania Modified by Sulfate Ions

摘要

The phase transitions, composition, morphology, and photocatalytic activity of titanium oxohy-droxide doped with sulfate ions during low-temperature hydrolysis in ammonia water have been studied. It has been found that in this synthesis method, a low degree of capture of sulfate ions by the synthesized product and a sufficiently high degree of their removal already at moderate temperatures of the heat treatment are due to the presence of sulfate ions in the precursor, preferably in the form of extraspheric particles. It has been shown that the initial temperature of anatase crystallization is higher the larger the concentration of sulfate ions in the precursor is; at the same time, the anatase-to-rutile transition temperature exhibits an inverse dependence. The dependences of the photocatalytic activity of nanosized titania on the precursor treatment temperature have been found to be extreme in character.