Photocatalytic properties of ZrO2 and Fe(III)/ZrO2 semiconductors prepared by a sol-gel technique

S. BOTTA; J.A. NAVÍO; M.C. HIDALGO; G.M. RESTREPO; M.I. LITTER

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 1999 vol. 129 p. 89 - 99

1010-6030

The photocatalytic efficiency of pure and 0.5?20 wt.% Fe-containing ZrO2 samples, prepared by a sol?gel technique, was tested in the transformation of environmentally important substrates, such as nitrite, EDTA and Cr(VI) and compared with that of TiO2 (Degussa P-25). All samples were active, although the efficiency was lower than that of TiO2. Nevertheless, the presence of iron increased the activity for nitrite photooxidation, with the maximum efficiency at 5 wt.% Fe content. At higher Fe content, the efficiency decreased but it was always higher than that of the undoped sample. For EDTA oxidation and Cr(VI) reduction, the same trend was observed. Remarkably, Cr(VI) reduction in the presence of EDTA was strongly accelerated, all zirconia samples being as active as P-25, although initial rates were lower and somewhat detrimentally affected by the presence of iron. The photocatalytic activity depends on the structural, surface and optical properties of the sample, on the preparation conditions and on the nature of the photocatalytic reaction.