TiO₂-Si- or SrTiO₃-Si-impregnated PVA–based low-cost proton exchange membranes for application in microbial fuel cell

Proton exchange membranes (PEMs) were synthesized in polyvinyl alcohol (PVA) matrix by impregnating TiO₂-Si or SrTiO₃-Si as proton exchanger for microbial fuel cells (MFCs). These PEMs were physically characterized, which approved the presence of hygroscopic oxides like SiO₂ to increase the proton transfer due to the formation of Si-H along with the water channelling through TiO₂ or SrTiO₃ induced microstructural modifications. Chemical characterization techniques further illustrated their comparable performance to the commercially available Nafion-117 and superior performance than bare PVA membrane. Polarization curves for MFCs using TiO₂-Si- or SrTiO₃-Si-based PVA membranes exhibited a power density of 6.16 ± 0.31 W m⁻³ and 5.39 ± 0.27 W m⁻³, respectively. Power density of MFC with TiO₂-Si membrane was comparable to that of the MFC using Nafion-117 (6.50 ± 0.33 W m⁻³). Thus, comparable properties and 30-folds less synthesis cost of the fabricated TiO₂-Si-impregnated PVA membrane in comparison to Nafion, demonstrate its potential for real-life applications in MFC. [Figure not available: see fulltext.]