Synergistic Effect of MXene Loading Into the Support and Polyamide Layer of TFNC Membranes: Improved Permeability and Rejection of Salt and Dye in Nanofiltration

Abstract The water shortage dilemma urges the development of nanofiltration membranes that surpasses the trade‐off between rejection and flux. This study explores the synthesis of MXene nanosheets and their incorporation into polysulfone (PSf)‐polyamide (PA) membranes to develop thin‐film nanocomposite (TFNC) membranes with enhanced nanofiltration performance. The effects of MXene loading at different stages‐ within the PSf support and PA selective layer‐ on the membrane's properties and performance are investigated. MXene incorporation significantly influenced membrane structure, increasing surface hydrophilicity, roughness, and charge density. Nanofiltration experiments demonstrated improved water permeability and salt rejection, particularly for membranes with MXene introduced into the PA layer. The highest pure water flux (PWF) of 43.12 Lm ^{− 2} h ⁻¹ is obtained for the TFNC membrane where MXene is incorporated into the PSf support and the m‐phenylenediamine (MPD) solution, which is 4 times as much as the MXene‐free thin‐film composite membrane. This membrane also provided the highest rejection for solutes, with 98.32% for Na ₂ SO ₄ and 99.13% for methyl orange. Additionally, MXene‐modified membranes exhibited superior antifouling properties, as reflected in higher flux recovery ratios (FRR). These findings highlight the potential of MXene as an effective nanofiller for fabricating advanced membranes with enhanced permeability, selectivity, and fouling resistance.