Titanium dioxide nanoparticles co-doped with Fe 3+ and Eu 3+ ions for photocatalysis

Abstract

Nanoparticles of titanium dioxide co-doped with Fe 3+ and Eu 3+ were prepared using the sol–gel method. The photocatalytic reactivities were evaluated by photodegradation of chloroform in solution. Nanocrystalline TiO 2 co-doped with Eu 3+ and Fe 3+ at optimal concentration (1 at.% Fe 3+, 0.5 at.% Eu 3+) shows a synergistic effect, which significantly increases the photodegradation activity of nano-TiO 2. The effects of the dopants in nanocrystalline TiO 2 particles on the photocatalysis were studied using the photo-electrochemical method. Two dopants of Fe 3+ and Eu 3+ in nanocrystalline TiO 2 play different roles in improving the photoinduced charge separation in the nanostructured semiconductor and in the interfacial charge transfer process at the semiconductor/solution interface. Fe 3+ serves as a hole trap and Eu 3+ as an electron trap in nanocrystalline TiO 2, respectively. The separation of the charge carriers is attributed to such trappings. In the meantime, Fe 3+ and Eu 3+ also speed up anodic and cathodic processes via improving interfacial charge transfers. Superior photocatalysis of nanocrystalline TiO 2 co-doped with Fe 3+ and Eu 3+ ions was related to the cooperative actions of the two dopants.