Electrifying CQDs‐doped PANI‐embedded membrane for enhanced self‐cleaning targeting wastewater treatment

Abstract

Abstract BACKGROUND Electrically conductive membranes have recently emerged as a promising solution, offering self‐cleaning properties with reduced fouling. In this study, we synthesized electrically conductive polyaniline (PANI) and carbon quantum dots‐doped PANI (CQDs/PANI) using Piper longum plant extracts and incorporated them into polysulfone/polyvinylpyrrolidone (PSF/PVP) membranes for improved self‐cleanliness by minimizing membrane fouling. RESULTS Optimized PANI and CQDs 40 /PANI (with 40% CQDs) achieved notable electrical conductance of 513.4 ± 24.1 and 997.3 ± 29.7 μS, respectively. The incorporation of 2% PANI and CQDs 40 /PANI into the membranes (denoted as PANI 2 ‐PVP 2 /PSF 12.5 and CQDs 40 /PANI 2 ‐PVP 2 /PSF 12.5 ) enhanced membrane conductivity to 4.23 × 10 −3 and 5.30 × 10 −3 S cm −1 , respectively. The CQDs 40 /PANI modification improved hydrophilicity and porosity (16.0 ± 1.2% to 66.1 ± 2.7%). The water flux of PVP 2 /PSF 12.5 , PANI 2 ‐PVP 2 /PSF 12.5 and CQDs 40 /PANI 2 ‐PVP 2 /PSF 12.5 membranes was measured as 316.0 ± 9.3, 435.4 ± 11.9 and 485.7 ± 14.4 L m −2 h −1 , respectively. Filtration of E. coli in phosphate buffer demonstrated significant fouling mitigation, with a reduced fouling from 69.1% to 49.3% and 34.5% for PANI‐ and CQDs 40 /PANI‐modified membranes, respectively, and flux recovery improved correspondingly, from 46.4% to 74.4% and 83.7% along with improved E. coli rejection from 63.7 ± 3.3% to 83.1 ± 2.9% and 96.5 ± 1.5%, respectively. E. coli ‐spiked sewage water filtration showed superior E. coli rejection (98.3 ± 2.3%) and fouling recovery (86.3 ± 2.1%) with lower fluxes than that of E. coli . Hagen–Poiseuille and resistance‐in‐series models showed <15% variations in theoretical and experimental fluxes. CONCLUSION The study achieved notable enhancement in the electrical conductivity, hydrophilicity and flux with the incorporation of CQDs/PANI. The developed membranes exhibit strong potential for mitigating fouling through an electrified self‐cleaning mechanism, enhancing the efficiency of wastewater treatment. © 2025 Society of Chemical Industry (SCI).