Hydrogen-substituted graphdiyne-facilitated polyamide membrane with improvement of water permeance

Abstract

High-permeance polyamide (PA) thin film composite (TFC) membranes with excellent rejection are essential for nanofiltration. The incorporating of an interlayer has been identified as an effective approach to achieve this objective. Herein, the hydrogen-substituted graphdiyne (HsGDY) interlayer modulated the micro-structure and surface/interface characteristics of PA membrane. The resultant HsGDY-PA membrane featuring a brick-mud architecture, enhances the surface hydrophilicity and provides more water transfer channels. Compared to the PA without HsGDY interlayer, the water permeance increased by 1.5 times to 153.9 L·m⁻²·h⁻¹·MPa⁻¹ with Na₂SO₄ rejection above 96.5 %. A 100-hour NF assessment demonstrates good stability of membrane. Additionally, the HsGDY-PA membrane exhibits over 90 % rejection for high-concentration salts solutions, such as 5.0 g·L⁻¹ Na₂SO₄ and MgSO₄ solutions, indicating its potential for the treatment of industrial wastewater. Notably, the separation factors for NaCl/antibiotics exceed 24.6, demonstrating its capability for the selective removal of NaCl from antibiotics wastewater systems.