TiO2-doped sulfonated poly(etheretherketone)/poly(vinyl alcohol) blend membrane synthesis for microbial fuel cell systems

This study explores the development and comprehensive evaluation of titanium dioxide (TiO₂)-doped, thermally crosslinked sulfonated poly(ether ether ketone) (SPEEK)/poly(vinyl alcohol) (PVA) blend membranes for microbial fuel cell (MFC) applications. The membranes were synthesized with varying TiO₂ concentrations and characterized through analyses of water content, ion exchange capacity, swelling behavior, mechanical strength, electrochemical impedance spectroscopy and Fourier transform infrared spectroscopy. Incorporation of TiO₂ significantly enhanced proton conductivity and reduced water-induced mass loss compared to undoped membranes. Among the various compositions, the membrane containing 5 wt% TiO₂ (SPEEK/PVA-5T) demonstrated the highest proton conductivity of 0.4346 S cm⁻¹ at 25 °C, indicating superior performance. The membranes were tested in a cylindrical H-type MFC setup. The SPEEK/PVA-5T membrane achieved a maximum voltage output of 560.610 mV and a power density of 62.856 μW m⁻², in comparison to a commercial Nafion 117 membrane, which delivered 777.740 mV and 120.975 μW m⁻². These findings underscore the potential of the SPEEK/PVA-5T membrane as an effective and sustainable alternative for MFC applications, offering enhanced ion transport and contributing to the advancement of carbon-neutral energy technologies. This work represents a meaningful step toward the development of high-performance, eco-friendly membrane materials for renewable energy systems. © 2025 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.