Spectroscopic characterization of bismuth embedded Y zeolites

摘要

Bismuth embedded Y zeolites were studied by using UV-vis- near infrared (NIR) diffuse reflectance, Raman, and steady-state NIR photoluminescence spectroscopy. The results suggest that Bi_5~(3+) and Bi~+ active centers coexist in the dehydrated and hydrated zeolite framework, both of which contribute to NIR emission. Furthermore, it was revealed that the high-temperature annealing leads to the formation of Bi_2O_3 clusters, which act as blocks for selectively closing down the "in-out windows" of H_2O and O_2 molecules in the zeolites. It is believed that these materials can find a wide array of applications as active media of broadly tunable micro or nano-optical sources.