Conductive carbon-polymer composite for bioelectrodes and electricity generation in a sedimentary microbial fuel cell

Abstract

Biofilm formation on conductive materials for bioelectrodes and electricity production in a microbial fuel cell (MFC) is important for different areas as bioremediation, production of biohydrogen, electricity, energy storage and even biomedical area. The development of conductive composites from residual materials with controlled surface morphology for bioelectroactive bacteria biofilm formation can overcome challenges as biocompatibility, stability, chemical/environmental inertness and low power density in a MFC. In this study a carbon-polymer composite was developed from residual banana peel and a bioelectrode was with electroactive bacteria was successfully obtained and applied as a new conductive material in a sediment microbial fuel cell (SMFC). Cyclic Voltammetry of the bioelectrodes demonstrated the conductive property of the composite and the presence of bioelectroactive biofilm attached. The process to obtain the activated carbon from banana peel was related with the bioelectrodes performances in the SMFC. The composite obtained at 700 °C showed the best results of power density, total chemical oxygen demand removed (TCOD) and coulombic efficiency (CE) of 1056.6 W/m3, 98% TCOD and 23.7% respectively. This power density was 10 times higher than that with a bioanode made with commercial carbon cloth. The feasibility of the electroactive biofilm formation on a carbon-polymer composite was confirmed and the use of banana peel residual for electricity production in a SMFC was proved for the first time.