A novel proton exchange membrane developed from clay and activated carbon derived from coconut shell for application in microbial fuel cell

Development of an affordable low-cost durable proton exchange membrane (PEM)for efficient performance of microbial fuel cell (MFC)is one of the major bottlenecks that need to be dealt with. Therefore, in this study, activated carbon derived from coconut shell (ACCS)has been blended with natural clay to prepare a low cost PEM with estimated cost of around 45 $/m². This is an approach to find effective alternative to the widely used commercially available costly Nafion 117 membrane. The X-Ray diffractogram of clay showed the presence of different hygroscopic oxides,which can enhance the hydration property of the PEM. Also, the superior specific surface area of activated carbon helped to retain the bound water for proton hopping to further enhance the proton transfer. These casted ACCS/Clay membrane showed higher proton diffusion coefficient (36 × 10^-6 cm²/s)than Nafion 117 membrane (4.64 × 10^-6 cm²/s). In addition, the performance of MFC was evaluated using this membrane, which showed ACCS/Clay membrane based MFC exhibited 1.5 times higher operating voltage and coulombic efficiency with two times higher power density as compared to MFC using Nafion 117 membrane. This low cost PEM thus has the potential to take MFC technology step forward for field scale application by eradicating the need of costly polymer membrane popularly used at present.