Improved power output by incorporating polyvinyl alcohol into the anode of a microbial fuel cell

In this study, polyvinyl alcohol (PVA) is proposed as a new binder to improve the power output of a microbial fuel cell. The physical and chemical properties of PVA are characterized with Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), contact angle testing, density functional theory calculations, and scanning electron microscopy (SEM). The electrochemical performance of an anode using carbon nanotubes as an electrocatalyst and PVA as a binder are evaluated in an Escherichia coli based fuel cell using chronoamperometry, electrochemical impedance spectroscopy (EIS), and polarization curve measurements, and a comparison is made with the conventional binder, polytetrafluoroethylene (PTFE). It is found that PVA is more hydrophilic and has stronger interactions with the bacterial membrane than PTFE. Accordingly, the anode with PVA as a binder facilitates the formation of biofilms and thus exhibits improved electron transfer kinetics between bacteria and the anode of the microbial fuel cell compared to the anode using PTFE. The MFC using PVA produces the largest maximum output power, 1.631 W m−2, which is 97.9% greater than the largest one produced by the MFC using PTFE (0.824 W m−2).