MXene-based composite forward osmosis (FO) membrane intercalated by halloysite nanotubes with superior water permeance and dye desalination performance

[Display omitted] •MXene/C-HNTs membranes were prepared by self-assembly nano-intercalation strategy.•The interlayer spacing of MXene was increased by insertion of C-HNTs.•The composite membrane showed a loose and stable channel after nano-intercalation.•MXene/C-HNTs membranes exhibited superior permeance and dye desalination performance. MXene two-dimensional (2D) laminate membranes have attracted many researchers in the field of membrane separation due to its adjustable interlayer spacing. However, MXene 2D laminate membranes has been inability to achieve dye desalination due to simultaneous rejection of both dyes and salts in salt-containing dye. The looser MXene/C-HNTs composite forward osmosis (FO) membrane was successfully prepared via vacuum filtering, in which halloysite nanotubes modified with cetyltrimethylammonium bromide (C-HNTs) and MXene (Ti3C2Tx) nanosheets were self-assembled by electrostatic interactions. The insertion of C-HNTs effectively increased the interlayer spacing and enhanced the compression resistance of the composite membranes. With a mass ratio of 1:3 between Ti3C2Tx nanosheets and C-HNTs, the composite membrane's pure water flux was raised to 191.4 L/(m2·h). The insertion of C-HNTs not only enabled the composite membrane to keep a superior dye rejection rate (CR rejection rate >99%), but also effectively reduced the rejection rate of monovalent salt (NaCl