TiO 2 -Si- or SrTiO 3 -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 TiO 2 -Si or SrTiO 3 -Si as proton exchanger for microbial fuel cells (MFCs). These PEMs were physically characterized, which approved the presence of hygroscopic oxides like SiO 2 to increase the proton transfer due to the formation of Si-H along with the water channelling through TiO 2 or SrTiO 3 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 TiO 2 -Si- or SrTiO 3 -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 TiO 2 -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 TiO 2 -Si-impregnated PVA membrane in comparison to Nafion, demonstrate its potential for real-life applications in MFC. Graphical abstract