Enhancement of microbial fuel cell efficiency by incorporation of graphene oxide and functionalized graphene oxide in sulfonated polyethersulfone membrane

Abstract

The present work examines, for the first time, the use of thiolated graphene oxide (TGO), in polyelectrolyte composite membranes as an effective approach to enhance the MFC performance. A new composite membrane based on a sulfonated polyethersulfone (SPES) hybrid with GO, sulfonated GO (SGO), and TGO was fabricated and assessed in MFC. The blend membranes were characterized with various techniques. The sulfhydryl (-SH) and sulfonic (-SO3H) groups enhanced the proton selectivity of the membrane and MFC performance. The MFC using the SPES/SGO1.8% composite membrane generated a power density of 66.4 mW/m2 which was double that produced by MFC using Nafion117 membrane in batch mode which lasted for 8 days. The SPES/SGO membrane was more selective towards H+ rather than other cations (K+, Na+, and Li+). This was also confirmed by the results of proton conductivity analysis, as the SPES/SGO1.8% membranes showed a value of 1.42 mS/cm which was higher than Nafion117 (1.3 mS/cm), SPES/TGO1.8% (1.25 mS/cm), SPES/GO1.8% (0.56 mS/cm), and SPES (0.32 mS/cm). The higher COD removal and coulombic efficiency were obtained in MFC with SPES/SGO membranes. In conclusion, it is our view that the new SPES/SGO and SPES/TGO membranes can be applied favorably in dual-chamber MFCs meeting their needs.