Improving MFC efficiency in power generation and COD removal by using protic ionic liquid in MWCNT-CS-2-aminothiazole-SO3H nanoparticle-infused sulfonated PES

•The hydrophilicity and water uptake of bare SPES improved by embedding MWCNT-CS-2-aminothiazole-SO3H in the polymer matrix.•The altered PEMs surpassed SPES regarding maximum COD removal and CE.•The SPES/MWCNT-CS-2-aminothiazole-SO3H 0.5 wt% represented a power density, 20 times enhancement compared to bare SPES.•The addition of MWCNT-CS-2-aminothiazole-SO3H to SPES reduced the oxygen mass transfer coefficient to 1.96 cm/s. This study exhibits a novel nanofiller, functionalized multi-walled carbon nanotube (MWCNT)/chitosan (CS) by 2-aminothiazole/SO3H. This synthesized nanofiller was incorporated with a fabricated sulfonated polyethersulfone (SPES) to manufacture a composite proton exchange membrane (PEM), SPES/MWCNT-CS-2-aminothiazole-SO3H. The composite membranes were fabricated by different percentage amounts of nanofiller (0.1 wt%, 0.5 wt%, 1.0 wt%, 1.5 wt%). The trait comparison of SPES/MWCNT-CS-2-aminothiazole-SO3H, SPES, and Nafion 117 membrane is performed to investigate their application in the microbial fuel cell (MFC). The fabricated composite membrane SPES/MWCNT-CS-2-aminothiazole-SO3H 0.5 wt% illustrated superior water uptake (WU) of 90.41 %. Moreover, the maximum power density (PD) (66.04 mW.m−2) was produced by SPES/MWCNT-CS-2-aminothiazole-SO3H 0.5 wt%, which demonstrated a considerable increase (approximately 20 times) compared to SPES (3.19 mW.m−2). Furthermore, the power density generated by the Nafion 117 membrane was 15.78 mW.m−2. In addition, the statistics in MFC usage presented that prepared composite membrane combined with MWCNT-CS-2-aminothiazole-SO3H 0.5 wt% had the optimum chemical oxygen demand (COD) removal, and the coulombic efficiency (CE), with 90.46 % and 80.68 %, respectively. Due to the high efficiency and remarkable power generation achieved by the MFC with SPES/MWCNT-CS-2-aminothiazole-SO3H 0.5 wt%, this modified membrane can be considered as a promising cost-effective alternative separator in MFC.