Zhen Yao1,Pengfei Li1,2,Kuo Chen1,2,Yang Yang1,André Beyer1,Q. Jason Niu3,Armin Goelzhaeuser1
Bielefeld University1,China University of Petroleum (East China)2,Shenzhen University3
Zhen Yao1,Pengfei Li1,2,Kuo Chen1,2,Yang Yang1,André Beyer1,Q. Jason Niu3,Armin Goelzhaeuser1
Bielefeld University1,China University of Petroleum (East China)2,Shenzhen University3
Ultrathin carbon nanomembranes (CNMs), fabricated from crosslinking self-assemblies of molecular precursors, are 2D membranes that possess well-defined physical and chemical properties.<sup>1</sup> Featuring a high density of sub-nanometer channels, CNMs enable superior salt separation performance compared to conventional membranes.<sup>2</sup> However, defect occurrence during synthesis and transfer processes impedes their technical realization on a macroscopic scale.<br/>Here, we introduce a practical and scalable interfacial polymerization method to effectively heal defects while preserving the sub-nanometer pores within CNMs. Defects in CNM composites were successfully repaired by interfacial polymerization of polyamide using m-phenylenediamine as the aqueous phase monomer and trimesoyl chloride as the oil phase monomer. The defect-healed CNMs exhibit exceptional performance in forward osmosis (FO), achieving a water flux of 105 L m<sup>−2</sup> h<sup>−1</sup> and a specific reverse salt flux as low as 0.1 g L<sup>−1</sup> when measured with 1M NaCl as draw solution. This water flux is ten times higher than commercially available FO membranes. Through successful implementation of the defect-healing method and support optimization, we demonstrate the scalable synthesis of fully functional, centimeter-scale CNM-based composite membranes, showing a water permeance comparable to commercial membranes and a salt rejection of ~99.8%. Our defect-healing method presents a promising pathway to overcome limitations in CNM synthesis, unlocking their potentials for practical salt separation applications.<br/><br/>(1) Turchanin, A.; Gölzhäuser, A. Carbon Nanomembranes. <i>Adv. Mater.</i> <b>2016</b>, <i>28</i> (29), 6075–6103. https://doi.org/10.1002/adma.201506058.<br/>(2) Yang, Y.; Hillmann, R.; Qi, Y.; Korzetz, R.; Biere, N.; Emmrich, D.; Westphal, M.; Büker, B.; Hütten, A.; Beyer, A.; Anselmetti, D.; Gölzhäuser, A. Ultrahigh Ionic Exclusion through Carbon Nanomembranes. <i>Adv. Mater.</i> <b>2020</b>, <i>32</i> (8), 1907850. https://doi.org/10.1002/adma.201907850.