Eco-friendly ascorbic acid-integrated graphene oxide composite membranes for high performance ionic and molecular sieving in wastewater treatment

Abstract

Herein, an eco-friendly GO-based composite membrane was successfully synthesized by integrating with ascorbic acid (AA). The crosslinking/bonding of GO and AA/GO composite membranes were evaluated using FT-IR technology. Surface morphology and cross-sectional investigations of the membranes were investigated by using scanning electron microscopy (SEM). The d-spacing of GO and AA/GO materials was measured using X-ray diffraction (XRD). The as-prepared membranes exhibit excellent permeability and rejection efficiency for numerous dyes and salts. The rejection efficiency and permeability of different dyes were measured as for rhodamine B (rejection 99.9% and permeance 180 ± 5 L m⁻² h⁻¹ bar⁻¹), for methylene blue (rejection 99.7% and permeance 245 ± 5 L m⁻² h⁻¹ bar⁻¹) and rose bengal (rejection 99.4% and permeance 270 ± 5 L m⁻² h⁻¹ bar⁻¹). In addition, the membrane showed good separation for NaCl (rejection 87.5% and permeance 335 ± 5 L m⁻² h⁻¹ bar⁻¹), Ni(NO₃)₂ (rejection 95.8% and permeance 255 ± 5 L m⁻² h⁻¹ bar⁻¹) and Pb(NO₃)₂ (rejection 98.9% and permeance 170 ± 5 L m⁻² h⁻¹ bar⁻¹). Furthermore, the as-prepared membranes are most stable in all three media up to 65 days. This approach highlights the potential practical applications of GO-based membranes in treating wastewater effluent from aqueous systems.