Photocatalytic degradation of atrazine by porphyrin and phthalocyanine complexes

This study principally focused on a new kind of photochemical reaction cata lyst: porphyrin and phthalocyanine complexes. In a first step, the preparat ion of the catalysts was optimized. A resin has been chosen to be the suppo rt of the complexes. Efficiency of catalytic activity is performed on the d egradation of a pesticide: atrazine. The best atrazine degradation occurs w ith 4.6% of complexes versus substrate. The role of the surface has also be en shown to be important. Then, their performances were demonstrated in ter ms of kinetics and degradation routes, compared to a classical catalyst: ti tanium dioxide. This study seeks to assess the efficiency of these systems both in a mercury lamp reactor and under solar irradiation which reduces en ergy costs. The best atrazine degradation half-life found for the complexes is about 200 min with the iron phthalocyanine. These catalysts exhibit par ticular oxidation activities. Indeed, the degradation routes have been foun d different between the semi-conductor and the metallic complexes. These co mplexes are able to cleave the triazinic ring more efficiently than the tit anium dioxide. (C) 2000 Elsevier Science Ltd. All rights reserved.