Manipulation and Simulation on the Luminescence Performance of Ag₃ ⁺ Cluster in Heteroatom Ga-FAU Zeolite

The manipulation of silver nanoclusters' luminescence performance in heteroatom zeolite was rarely reported. In this research, the heteroatom Ga-FAU zeolites were synthesized together with the AlFAU zeolite, based on which a series of Ag nanoclusters loaded AlFAUAg and mGaFAUAg zeolites were prepared. The spectroscopy characterization indicated that emission intensity of silver nanoclusters is greatly enhanced in Ga-containing zeolites compared to that in AlFAUAg, and meanwhile, the excitation and emission peak showed redshift and blueshift, respectively, with the introduction and increasing proportion of Ga atoms in mGaFAUAg. The TD-DFT method was carried out on the [Ag₃Ga_xD6r]⁺ (x = 0, 1, 2, 3, 4, 5) clusters to study the effect of framework Ga on the luminescence properties of Ag₃ ⁺ in the D6r cavity of FAU zeolite, which suggested that the S₁ → S₀ transition of Ag₃ ⁺ is responsible for the radiative visible emission. Moreover, the low-energy shift for S₃ → S₀ transition and high-energy shift for S₁ → S₀ transition were observed with increasing x value in [Ag₃Ga_xD6r]⁺ clusters, which is in accordance with the experimental observation. This research provided an alternative method for the manipulation of silver nanoclusters' luminescence performance by using heteroatom zeolite, which contributed to the design of solid phosphors with desirable emission.