Interaction between the exchanged Mn(2+) and Yb(3+) ions confined in zeolite-Y and their luminescence behaviours

Luminescent zeolites exchanged with two distinct and interacted emissive ions are vital but less-studied for the potential applications in white light emitting diodes, solar cells, optical codes, biomedicine and so on. Typical transition metal ion Mn(2+) and lanthanide ion Yb(3+) are adopted as a case study via their characteristic transitions and the interaction between them. The option is considered with that the former with d-d transition has a large gap between the first excited state (4)T(1) and the ground state (6)A(1) (normally >17,000 cm(−1)) while the latter with f-f transition has no metastable excited state above 10,000 cm(−1), which requires the vicinity of these two ions for energy transfer. The results of various characterizations, including BET measurement, photoluminescence spectroscopy, solid-state NMR, and X-ray absorption spectroscopy, etc., show that Yb(3+) would preferably enter into the zeolite-Y pores and introduction of Mn(2+) would cause aggregation of each other. Herein, cation-cation repulsion may play a significant role for the high valence of Mn(2+) and Yb(3+) when exchanging the original cations with +1 valence. Energy transfer phenomena between Mn(2+) and Yb(3+) occur only at elevated contents in the confined pores of zeolite. The research would benefit the design of zeolite composite opto-functional materials.