Ostwald Ripening-Mediated Grafting of Metal-Organic Frameworks on a Single Colloidal Nanocrystal to Form Uniform and Controllable MXF

MXF, a metal-organic framework (MOF) that contains more than two components, such as heterogeneous inorganic nanoparticle@MOF (NP@MOF) with precisely defined structures, is important in applications such as catalysis, energy, and biochemistry. However, the ambiguous growth mechanism of MXF has hindered the exploration of controllable design of nanoparticle level MXF complexes. Here, we report an Ostwald ripening-mediated grafting of MOF on a single multidentate inorganic colloidal nanocrystal via heterogeneous nucleation. The grafting relies on the carboxylic acid groups anchored on the surface of the colloidal nanocrystal. Ostwald ripening-mediated grafting enabled us to obtain uniform MXF with a wide range of sizes of nanoparticles and a controlled thickness of the MOF layer on the surface of colloidal nanocrystal. A dual FRET-induced singlet oxygen generation with near-infrared light was achieved from an UCNP@ZrMOF hybrid. This generalizable grafting strategy provides insight into the design of MXF nanoparticles for a wide range of applications involving advanced functional materials.