NH₂-MIL-125 Nanosheets Prepared via Crystallization Kinetics Modulation for Ultrathin Membrane Fabrication

Regulating both crystallographic orientation and thickness of titanium metal-organic framework (Ti-MOF) membranes remains a significant challenge. In this study, we pioneered the fabrication of uniform 29 nm thick NH₂-MIL-125 nanosheet seeds by employing crystallization kinetics modulation approach. Through innovating confined counter-diffusion-assisted epitaxial growth under single-mode microwave heating, a highly c-oriented 80 nm thick NH₂-MIL-125 membrane was prepared. Significant reduction in thickness endowed the membrane with unprecedented H₂ permeance (1350 GPU) along with considerable H₂/CO₂ selectivity (19.1), exceeding the performance benchmarks of state-of-the-art NH₂-MIL-125 membranes.