Enhancement of electrochemical performance in PVDF-co-HFP cation exchange membrane with modifications by doping PP13-TFSI ionic liquid and sulfonation

Microbial fuel cells (MFCs) represent a promising clean energy technology with significant application potential. However, their implementation is constrained by the limitations of current membrane materials. Polyvinylidene fluoride-hexafluoropropylene (PVDF-co-HFP) is a material that has garnered interest in the field of electrochemical systems because of its facile moldability into various shapes and sizes of membranes, positioning it as a highly promising alternative to high-cost commercial membranes. Nevertheless, enhancing its electrochemical characterization remains a pivotal challenge to be surmounted for its broad adoption. In this study, an efficient PVDF-co-HFP membrane, augmented with PP13-TFSI ionic liquid and sulfonation (Membrane P-I&S), was successfully synthesized, and its potential as an ion exchange membrane in MFCs was evaluated. The findings indicated that chlorosulfonic acid considerably enhances the hydrophilicity and proton transport properties of PVDF-co-HFP, with the ionic liquid posited as an effective means to augment the sulfonation effect. An MFCs incorporating Membrane P-I&S demonstrated a remarkable current production capacity and power density, exceeding those of the unmodified membrane by more than two and threefold, respectively. In addition, the MFCs based on Membrane P-I&S displayed prolonged cycling stability with a notably porous architecture and enhanced biofouling resistance. This study validates the development of a high-efficiency, cost-effective, and environmentally friendly membrane fabrication approach for application in bioelectrochemical systems. This will help promote the application of MFCs in the field of wastewater treatment and resource recovery. • Performances of PVDF-co-HFP membrane were enhanced by PP13-TFSI and sulfonation. • Hydrophilicity and proton transport property of membrane were enhanced by sulfonation. • Ionic liquids are promising for enhance the sulfonation to PVDF-co-HFP membrane. • F, S, and functional groups play a role in better performance of PVDF-co-HFP membrane. • Membrane P-I&S have better structure with more microporous and biofouling capability.