In Situ Synthesis and Defect Engineering of MOF-76 by Electron Beam Irradiation: Balancing Crystallinity and Defects for Uranyl Capture

High-energy electron irradiation provides an exceptionally fast, energy-dense route to fabricate porous crystalline frameworks, yet its utility for MOFs is fundamentally limited by a trade-off between accelerated crystallization and radiation-induced damage. Here, we show that this trade-off can be actively navigated by the systematic modulation of the irradiation dose. Using MOF-76 as a model, we identify a dose-dependent maturation regime centered at 120 kGy, at which the material retains high crystallinity while exhibiting a maximized concentration of beneficial defects. Comprehensive characterization confirms the coexistence of preserved framework order and enhanced defect density at this dose. The optimally defective MOF-76 displays markedly improved uranyl ion uptake, reaching a maximum adsorption capacity of 441 mg g –1, which is 4.4-fold higher than that of solvothermally synthesized MOF-76, outperforming both the pristine material and samples produced at other doses in terms of capacity and adsorption kinetics. These results establish dose-controlled electron-beam irradiation as a practical means to tailor defect landscapes in MOFs, enabling the rational design of high-performance adsorbents for radionuclide remediation and related separations.