Embedding Nanocluster in MOF via Crystalline Ion-Triggered Growth Strategy for Improved Emission and Selective Sensing

Abstract

Metal-organic frameworks (MOFs) containing metal nanoclusters (NCs) display great potentials, but the fabrication faces challenges because of the serious agglomeration of NCs during the MOF growth. We report a crystalline ion-triggered growth strategy for embedding AuNCs in ZIF-8. As control, when the encapsulation was triggered with other metal ions (e.g., Ca²⁺, Pb²⁺, Cd²⁺, Na⁺, Fe³⁺, Cu²⁺, and Ni²⁺), the AuNCs failed to be encapsulated. The quantum yields and lifetime of AuNCs were greatly enhanced after embedding in ZIF-8. The AuNCs@ZIF-8 were then successfully applied for the selective sensing of H₂S both in liquid and gas phases. This crystalline ion-triggered growth strategy was easily extended to other systems, such as AgNCs@ZIF-8 and AuNCs@ZIF-67, indicating the general adaptability of this design protocol.