Ultrathin and stable organic-inorganic lamellar composite membrane for high-performance organic solvent nanofiltration

Two-dimensional (2D) lamellar membranes hold a broad prospect for separation applications. However, their design and development need controllable fabrication of ultrathin and stable lamellar membranes. Here, an organic-inorganic lamellar composite membrane with layer-by-layer graphene oxide (GO) and polyethyleneimine (PEI) structure was fabricated through a dual-needle electrostatic atomization strategy. The GO nanosheets work as skeleton to ensure ultrathin and defect-free membrane structure, while PEI cross-links adjacent GO nanosheets for structure stability. Importantly, this membrane achieves fast polar solvent permeance: 46.2 and 146.8 L m −2 h −1 bar −1 for water and acetone, outperforming most reported GO-based membranes. Meanwhile, the ordered and cross-linked interlayer channels provide accurate size sieving for industrial dyes (larger than 1.6 nm) with the rejection of above 96%. Significantly, this lamellar composite membrane displays excellent structure, operation, pressure, and cycling stabilities, which are difficult for traditional lamellar membranes.