Pristine graphene nanosheets prepared by supercritical CO2 circulating jet cavitation for MoS2-intercalated tubular nanofiltration membranes

GNs were prepared by scCO 2 circulating jet cavitation. • Pristine GN was used to construct tubular α-Al 2 O 3 membranes. • MoS 2 hybridization widens and stabilizes graphene laminar channels. • The G 8 M 2 membrane exhibits outstanding dye/NaCl separation performance. Pristine graphene nanosheets provide a low-functional-group scaffold for laminar nanofiltration membranes, but compact, poorly wetted pathways limit water transport. Here, pristine graphene nanosheets were produced by a circulating supercritical CO 2 (scCO 2 ) jet-cavitation process and deposited on porous α-Al 2 O 3 tubular supports. MoS 2 nanosheets were incorporated as hydrophilic, locally distributed two-dimensional channel-regulating components, forming heterogeneous GN/MoS 2 lamellar pathways that increased water permeance while maintaining dye selectivity. A PEI@GA-crosslinked surface layer supplied positive charge. The optimized G 8 M 2 membrane rejected more than 99% of CBB, CR, and BY, with water permeances of 110.24–131.04 L·m −2 ·h −1 ·bar −1 . In dye/NaCl feeds, it achieved a permeance of 139.16 L·m −2 ·h −1 ·bar −1 and separation factor of 866.87 for CR/NaCl, with a flux recovery ratio above 97% during the tested CR fouling cycles. During the 120 h CR/NaCl separation stability test with periodic hydraulic rinsing every 12 h, the membrane delivered an average permeance of 124.46 L·m −2 ·h −1 ·bar −1 and an average CR rejection of 99.60%, while maintaining low NaCl rejection. This work integrates nonoxidative graphene exfoliation, tubular membrane construction, and heterogeneous two-dimensional channel regulation for dye/salt fractionation. Download: Download high-res image (75KB) Download: Download full-size image