Self-oxygenated anatase–rutile phase junction: ensuring the availability of sufficient surface charges for photocatalysis

Abstract

A peroxide assisted solvothermal strategy has been developed for the synthesis of self-oxygenated anatase–rutile mixed phase yellow TiO₂. The yellow TiO₂ possessed surface oxygen richness which has increased absorption to the visible region. The addition of peroxide to the isopropanol–titanium(IV) butoxide mixture paved the way for self-oxygenation. The self-oxygenated titania has enormous oxygen at its surface, and hence a negative charge cloud. This is beneficial for the selective degradation of cationic pollutants which is of great interest in contemporary society. This negatively charged surface of the self-oxygenated, anatase–rutile yellow titania mixed phase formed below the anatase to rutile transition temperature ca. 300 °C has facilitated more efficient solid–solid interfaces and thus interparticle charge transfer in photocatalysis. This strategy is directed towards more efficient photocatalysis of self-oxygenated mixed phase yellow TiO₂ than that of the commercially available photocatalyst P25 titania.