Tunable-Emissive Zeolite-Confined Silver Nanoclusters as a Rapid and Highly Sensitive Photoluminescent Sensor for Trace Water Detection in Organic Solvents.

Zeolite-confined silver nanoclusters (AgNCs/Zeolite) are highly promising luminescent materials. Nevertheless, the controlled synthesis of AgNCs/Zeolite composites with tunable luminescent responses remains a persistent challenge. In this study, highly luminescent AgNCs/Zeolite composites are developed through the counter-cations engineering strategy via confining AgNCs within the cages of FAUX with Na and Zn as the counter cations (Ag-FAUX(Na/Zn)), which show water-triggered switchable yellow/green tunable-emissive properties with PLQY up to 90% and high tolerance to chemical reduction. Specifically, dehydration of Ag-FAUX(Na/Zn) increases its PLQY from 60% to 90% and shifts the emission peak from 560 to 520 nm, whereas the yellow emission of the sample without Zn (Ag-FAUX(Na/Zn)) is almost completely quenched upon dehydration. The remarkably enhanced luminescence upon dehydration can be tentatively ascribed to the coordination of Zn with framework oxygen (O) of FAUX, thereby preventing AgNCs from direct interaction with O of Ag-FAUX(Na/Zn), and finally forming the stable, tightly confined Ag interacting with nonframework oxygen and zinc atoms simultaneously. The Ag-FAUX(Na/Zn) composites demonstrated exceptional performance in fluorescence detection of trace water in organic solvents, achieving high sensitivity, a low detection limit of 0.015% v/v, rapid response times of less than 0.5 s, and reusability, thereby positioning it as a promising candidate for advanced fluorescence detection applications.