Among electrochemical cells, microbial fuel cells (MFCs) are special types of biofuel cells, producing electric power by utilizing microorganisms, instead of isolated enzymes, to assist redox reactions . The conventional MFC is a twochamber system, consisting of anode and cathode chambers that are separated by a proton exchange membrane (PEM). This system has been half biological, because only the anode side contains electrochemically-active microorganisms, while the cathode is abiotic. The microorganisms function as biocatalysts, motivating the degradation of organic materials to produce electrons, which travel to the cathode side via an electric circuit. The presence of free electrons on the cathode of MFCs initiates a reduction reaction of oxygen to produce water