Lanthanide oxide-doped titanium dioxide: Effective photocatalysts for the degradation of organic pollutants

A series of lanthanide oxide-doped titanium dioxide photocatalysts Ln(2)O(3 )/TiO2 (Ln(3+) = Eu3+, Pr3+, Yb3+) were prepared. The photocatalysts reveal a substantially enhanced activity for the degradation of organic pollutant s, as compared to undoped TiO2. The photodegradation processes of p-nitrobe nzoic acid, (1), p-chlorophenoxyacetic acid, (2), aniline, (3), salicylic a cid, (4), and trans-cinnamic acid, (5), with the different photocatalysts w as examined. The photodegradation of (1)-(5) is significantly faster with L n(2)O(3)/TiO2 photocatalysts and leads to complete mineralization of the or ganic compounds. The high activity of the Ln(2)O(3)/TiO2 photocatalysts is attributed to the enhanced association of the functionalized organic pollut ants to lanthanide-ion surface sites. (C) 1999 Kluwer Academic Publishers.