Universal In-Plane Confined Growth of Mesoporous Metal–Organic Framework Crystalline Heterostructures

Abstract Constructing mesoporous MOF heterostructures on conductive two-dimensional hosts remains challenging because interfacial contact and pore accessibility are rarely optimized simultaneously. Herein, we report a universal in-plane confined growth strategy for mesoporous UiO-66-NH2/MXene heterostructures featuring continuous interfacial contact and vertically accessible mesochannels. In contrast to conventional particle-on-sheet hybrids, the resulting architecture enables improved electrolyte penetration, shortened Zn2+ transport pathways, and efficient interfacial electron transfer. By regulating micellar assembly at the interface, an optimal mesostructural regime is identified in which ion accessibility and structural confinement are best balanced. Consequently, the optimized heterostructure delivers a high energy density of 163.9 Wh kg–1, excellent rate capability (∼68% retention over a 50-fold current increase), and ∼100% capacity retention over 50,000 cycles. Kinetic analyses and ex situ studies further show that the interfacial mesoporous architecture suppresses diffusion limitations and preserves structural integrity during Zn2+ storage. Moreover, the assembly concept shows transferability across substrates of different dimensionalities, highlighting its broader utility for constructing mesoporous crystalline heterostructures. This work provides an effective route to mesoporous MOF heterostructures and a generalizable design principle for hybrid crystalline electrodes.