The photodecomposition of phosmet over UV irradiated silver nanoclusters doped in mordenite zeolite

Ag(l) nanoclusters doped in mordenite zeolite were prepared and spectroscopically analyzed. Both experimental and theoretical results show the presence of silver nanoclusters with various sizes and environments in the zeolite hosts. The study indicates that the low energy emission mode (at 520 nm) was gradually activated and the high energy mode (at 415 nm) was deactivated upon increasing the excitation wavelength from 250 to 300 nm. The catalyzed system increases the photodecomposition of phosmet in comparison with the uncatalyzed experiment upon irradiation with different UV lights. Moreover, the largest catalytic activity was observed upon the irradiation of the catalyzed solution with 302 nm where an increase in the decomposition rate by 40-fold was observed. The photodecomposition products are similar for all systems but variations in the relative amount of these products were observed at different conditions. Both catalyzed systems indicate the formation of phosphorothionic acid (3) as the major product. (c) 2007 Elsevier B.V. All rights reserved.