Novel route to size-controlled synthesis of MnFe₂O₄@MOF core-shell nanoparticles

Nanoscale metal-organic framework (nMOF) is a distinctive type of crystalline compounds that consists of metal ions or clusters coordinated to organic ligands. This hybrid material has attracted fast-growing attention due to its tunable pore sizes, remarkably large surface areas, and high selectivity in uptaking small molecules. In this paper, we successfully developed a novel approach for synthesizing a core-shell structure with MIL-88B-4CH₃ as a tunable nMOF shell and MnFe₂O₄ as a magnetic core. We controlled the growth of the core-shell particles by introducing different acetic acid concentrations and with varied reaction time. Acetic acid works as a modulating agent that allows for nucleation rate control, leading to tailored particle size. Our results show an increase in the particle size with increasing acetic acid concentration or reaction time. This study provides a valuable methodology for synthesis of core-shell nanoparticles with controlled sizes based on nMOF platforms.