Luminescence properties of silver(I)-exchanged zeolite Y and its use as a catalyst to photodecompose carbaryl in the presence of natural organic matter.

Silver-doped Y-type zeolites with different silver loadings were prepared and analyzed spectroscopically at various temperattires. Several emission bands were observed for each AgY sample. Each emission band becomes dominant over the others by selecting a suitable excitation wavelength, indicating the presence of different silver clusters in zeolite Y. The study shows that the presence of AgY catalysts increases the photodecomposition rate of carbaryl by 4-42 times in comparison to the catalyst-free system, with the rate dependent on the amount of silver that was loaded on the Y-type zeolites. The presence of different concentrations of Suwannee River natural organic matter (NOM) affected the photodegradation reaction of carbaryl by allowing it to proceed via two different pseudo-first-order pathways. However, the presence of the silver-doped zeolite catalysts makes the photodecomposition of carbaryl proceed via first-order kinetics. [ABSTRACT FROM AUTHOR]