Nafion as a nanoproton conductor in microbial fuel cells

Abstract

Nafion, a sulfonated tetrafluoroethylene copolymer, consists of a hydrophobic fluorocarbon backbone (–CF2–CF2–) to which hydrophilic sulfonate groups ($SO^ - _3$ ) are attached. The presence of negatively charged sulfonate groups in a nanomembrane brings about a high level of proton conductivity. In this study, Saccharomyces cerevisiae was used for production of bioelectricity in a 2-chambered microbial fuel cell (MFC). We selected 9- c$m^ 2$ Nafion 117 and Nafion 112 as nanomembranes to transport the produced proton from the anode chamber to the cathode compartment at ambient temperature and pressure. Initial glucose concentration was 30 g/L. The maximum obtained voltage, current, and power density for Nafion 117 were 668 mV, 60.28 mA/$m^ 2$ , and 9.95 mW/$m^ 2$ , respectively. For Nafion 112, those results were 670 mV, 150.6 mA/$m^ 2$ , and 31.32 mW/$m^ 2$ , respectively.