Suppressing Ostwald Ripening Enables Programmable Growth of Radially Hierarchical MOF Superstructures Toward Multichannel Optical Waveguiding

Metal‐organic frameworks (MOF) homostructures or heterostructures with domain‐controlled emissive colors have demonstrated significant potential for high‐throughput sensing, anti‐counterfeiting, and information encryption. However, the precise construction of heterostructures with radially branched units remains challenging, primarily because the Ostwald ripening effect during crystal growth tends to drive one‐dimensional elongation. Here, we propose a programmable nucleation‐controlled strategy to spatially construct radially hierarchical MOF superstructures. During crystal growth, suppression of the Ostwald ripening effect triggers stable nucleation events in the system. Subsequently, the relatively high surface energy at the tips of 1D microrods promotes the secondary nucleation on the terminal facets, thereby leading to the formation of radially hierarchical superstructures. The acquired radial architectures with small angular deviations enable efficient multichannel optical signal output. The suppressing‐Ostwald‐ripening‐driven programmable growth paradigm provides a new route for the synthesis of multichannel waveguiding heterostructures and shows broad application prospects in advanced optoelectronic devices, multi‐channel information transmission, and encryption technologies.