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

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.