Activated carbon derived from ground nutshell as a metal-free oxygen reduction catalyst for air cathode in single chamber microbial fuel cell

Abstract

A single-chamber microbial fuel cell (SCMFC) was constructed using activated carbon derived from ground nutshells (GAC) as a metal-free cathode catalyst. The prepared cathode catalyst was characterized by X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), and Field emission scanning electron microscopy (FE-SEM), which demonstrates the chemical composition and the surface morphology of the synthesized material. The electrochemical characteristics of the cathode were investigated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) analysis, which confirmed the high charge transfer capacity and catalytic activity property of GAC catalyst material. The MFC with GAC catalyst produces a maximum output voltage of 0.619 V and which is 1.61 times greater than that of bare carbon cloth (CC). For Pt/C and GAC-modified CC, high power density values of 0.763 W m−2 and 0.521 W m−2 were obtained at current densities 1.65 A m−2 and 1.0 A m−2, respectively at 100 Ω. These results demonstrate that the GAC/CC is a promising cost-effective cathode catalyst for SCMFC.