Ultrathin carbon membranes are attractive for gas separation due to their high permeance but are typically limited by low selectivity. We report a new class of disrupted ultrathin carbon membranes (d-UCMs), sub-10 nm thick films synthesized via oxygen-assisted pyrolysis of poly(4-vinylpyridine) (P4VP) on nickel substrates. Controlled oxygen exposure modifies the carbonization process, yielding a nanostructure with disordered domains and hierarchical porosity. This structural disruption enables a rare combination of high hydrogen selectivity and permeance, overcoming the conventional trade-off in membrane design. Spectroscopic and structural analyses reveal that oxygen does not act as a dopant but instead reshapes the carbon framework by removing weak linkages while preserving nitrogen-rich motifs. The resulting membranes exhibit stable performance at elevated temperatures. This work presents a general strategy for tuning nanostructure in ultrathin carbon films via reactive atmosphere control, effectively bridging the gap between conventional carbon molecular sieve and carbon nanomembrane technologies.
Reference
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[2] Genduso, G.; Ogieglo, W.; Wang, Y.; Pinnau, I. Journal of Membrane Science 2024, 699, 122533.
