Zeolite photochemistry: energy transfer between rare-earth and actinide ions in zeolites

Abstract

Energy transfer is an important process in various display and luminescence devices. This paper shows that energy transfer efficiencies can be controlled by selectively placing certain inorganic ions in zeolite molecular sieves. The energy transfer in these zeolites occurs between uranyl ions and europium(III) ions in various zeolites. Three-dimensional channels in crystalline materials provide better interactions for energy transfer than two-dimensional or zigzag channels such as in mordenite and ZSM-5. Different synthetic procedures involving simultaneous and sequential ion exchange yield different efficiencies of energy transfer. The mechanism is believed to be of the short-range electron-exchange type for crystalline ZSM-5, modenite, and Y zeolite and of the long-range type for amorphous materials derived from zeolite A. 26 references, 2 figures, 2 tables.