ZIF-8-MXene/Nylon composite membrane for high-efficiency hydrogen purification

Metal-organic framework (MOF) membranes exhibit remarkable potential for gas separation due to their tunable porous structure and well-defined molecular sieving channels. However, the rapid growth of continuous, defect-free MOF membranes on microporous polymer substrates remains a significant challenge. In this work, we proposed a substrate modification strategy via MXene stacking, where large-flake MXene nanosheets were employed to construct a functional coating that simultaneously reduced substrate surface roughness and enhanced its conductivity for subsequent ease growth of MOF membrane. By combining spray coating with fast current-driven synthesis method (FCDS), we successfully fabricated a series of ZIF-8-MXene/Nylon composite membranes. Compared with conventional secondary growth or solvothermal methods, this approach offered superior fabrication efficiency, membrane uniformity, and operational simplicity, where a high-quality membrane could be prepared within 1 h. Under optimal conditions, the ZIF-8 30 min -MXene/Nylon composite membrane achieved outstanding separation performance, with H 2 permeance of 2032.3 GPU and H 2 /CO 2 selectivity of 87.2, surpassing the Robeson upper bound (2008). Importantly, this work provided valuable insights into MOF membrane fabrication on microporous polymer substrates.