Hybridization of nanofiltration and photocatalysis via functionalized graphene quantum dot-blended membranes for the degradation and removal of amoxicillin

Background Antibiotic contaminants in wastewater have emerged as a critical environmental concern due to their persistence and ability to promote antimicrobial resistance in natural microbial communities. Among advanced treatment strategies, photocatalytic degradation offers a solution by breaking them into harmless byproducts, though challenges like poor stability and catalyst recovery remain Methods This study explores the UV-driven photocatalytic degradation of amoxicillin using polyethersulfone (PES) membranes blended with N,S-doped graphene quantum dots (N,S-GQDs) prepared via phase inversion. The membranes were characterized by FTIR, SEM, XRD, AFM, and tensile strength analysis and photocatalytic performance was further evaluated to assess their degradation efficiency. Significant Findings The quantum dots incorporated membrane exhibited a reduced water contact angle of 47.7°, indicating enhanced hydrophilicity and water flux. DRS analysis revealed that incorporating N,S-GQDs effectively reduce the bandgap and enhanced its overall optical activity. The superior performance of N,S-GQDs is attributed to their structural properties, which facilitate efficient interaction between the photocatalyst and pollutants. Amoxicillin degradation was systematically evaluated under varying pH [3–11], catalyst loading, and cycle numbers, with maximum efficiency achieved at pH 11. The hybrid membrane showed a flux recovery ratio (FRR) of 78% after AMX treatment, confirming its enhanced antifouling capability compared to pristine PES.