Emission-tunable silver clusters constrained within EMT zeolite

Abstract

Zeolite confined silver clusters (AgCLs) are favored by scientific researchers due to their unique luminescent properties. However, it remains a challenge to optimize luminescent silver-loaded zeolites through simple and effective methods. In this work, the effect of surface modification on the dynamic luminescence abilities of silver clusters in zeolites was discussed for the first time. A series of luminescent silver nanoclusters (from yellow-green emission to blue emission) were fabricated by introducing Ag⁺ ions into EMT zeolites and PEG400-modified EMT zeolites, respectively. It is also noteworthy that modification of the EMT zeolite surface with PEG400 significantly improves the luminescence intensity and photoluminescence quantum yields, which may be ascribed to the increase of hydroxyl (–OH) functional groups in the surface of PEG400-modified EMT zeolites, thereby promoting the reduction of Ag⁺ and accelerating the nucleation rate of luminescent silver nanoclusters. Moreover, even at increasing thermal temperature, the sample modified by PEG400 still maintains intense blue light and only presents a slight thermal quenching effect, showing superior stability. Therefore, in terms of optical properties and stability, such a sample synthesized by us possessing a high PLQY of 53% and good thermal stability can be considered as a suitable candidate to replace the traditional commercial blue-emitting phosphor (BaMgAl₁₀O₁₇:Eu²⁺) for full spectrum white lighting. Furthermore, a white LED lamp was obtained by combining the composites and commercial phosphors on a 365 nm NUV-LED. This work contributes to a valuable reference for the rational design of luminescent silver-loaded zeolites with promising new functionalities and stimulates the great potential of luminescent silver nanocluster zeolite composites in developing promising phosphors for high-quality lighting.