Phthalocyanine-modified titania - catalyst for photooxidation of phenols by irradiation with visible light

The photooxidation of phenol, catalyzed by superficially modified with phthalocyanine complex (Pc) oxide supports (Al2O3 or TiO2), has been studied upon irradiation with visible light. The rate of substrate photooxidation, catalyzed by Pc/TiO2, is much higher than that over the sample obtained by anchoring the Pc complex on Al2O3. The degree of mineralization of phenol during photocatalysis in the presence of Pc/TiO2 is also higher. The high photocatalytic activity of the sample is explained by the realization of an electron transfer from the conduction band of the excited phthalocyanine semiconductor particles to the conduction band of TiO2 support. The increase of the quantum yield of the redox process comes as a result of the additional formation of superoxide radicals on the TiO2 conduction band. (C) 2002 Elsevier Science B.V. All rights reserved.