A novel low cost polyvinyl alcohol-Nafion-borosilicate membrane separator for microbial fuel cell

• Novel membranes using PVA and borosilicate composite were fabricated.
• Proton diffusion for MPN was comparable with Nafion117.
• MFC-PN produced power density comparable to MFC with Nafion 117 membrane.
• MPN was fabricated at almost 11 times reduced cost than Nafion 117 membranes.

Composite membranes were developed from PVA-borosilicate (MP) and PVA-Nafion-borosilicate (MPN) for application in microbial fuel cells (MFCs). The membranes were characterized in terms of water uptake, PBS uptake, oxygen diffusion and proton conductivity. Proton conductivity for MPN (0.07 Scm−1) was found to be higher as compared to that of MP (0.03 Scm−1). Oxygen diffusion coefficient for MPN was 1.47 fold lower than that for MP. As a result, MFC with PVA-Nafion-borosilicate membrane exhibited maximum power density of 6.8 Wm−3, which was 151% higher than the power produced by MFC having PVA-borosilicate membrane and it was comparable with MFC using Nafion 117 (7.1 Wm−3) membrane separator. This study demonstrates that borosilicate glass membrane incorporated with PVA-Nafion matrix can be a suitable alternative to costly polymeric membrane to increase power output of MFC. Using such membranes MFC can be fabricated at around 11 fold reduced cost as compared to Nafion 117.