Enhanced photoluminescence and stability of CsPbBr3 quantum dots by anchoring on metal-organic frameworks for Cu2 + detection fluorescence probe

Abstract

Construction of perovskite quantum dots (PQDs)/Metal-Organic Frameworks (MOFs) nanocomposites is anticipated to simultaneously enhance PQDs stability and expand functionality. However, pivotal challenges still exist, such as difficulty in synthesis, unclear interactions between PQDs and MOFs, and expansion of new applications. Herein, a straightforward strategy is proposed to obtain the PQDs/MOFs nanocomposites (i.e., CsPbBr₃/PCN-333(Fe)) by surface treatment of CsPbBr₃ PQDs using PCN-333(Fe) MOF. The anchoring effect is conferred by the strong interaction of the abundant carboxylate group of PCN-333(Fe) with the uncoordinated Pb²⁺ on the surface of PQDs, thus passivating such defects of PQDs. Besides, the PCN-333(Fe) with a large specific surface area of 2237 m²/g provides an excellent matrix for uniform spatial distribution of CsPbBr₃ PQDs. The PQDs/MOFs nanocomposites exhibit significant photoluminescence (PL) enhancements (6.5 times that of CsPbBr₃) and improved stability in air compared with CsPbBr₃. At last, the fluorescence probe based on PQDs/MOFs nanocomposites shows a greatly-improved sensitivity for selective detection of Cu²⁺ in hexane, with the limit of detection (LOD) as low as 1.63 nM, compared to 2.89 nM for pure CsPbBr₃ probe. This work offers a facile way to prepare PQDs/MOFs nanocomposites, which is applicable for widespread applications such as optoelectronics, photocatalysis, sensors, and bioimaging.