Investigation of Polymer Biofilm Formation on Titanium-Based Anode Surface in Microbial Fuel Cells with Poplar Substrate

Ahmet Erensoy,Nurettin Çek

doi:10.3390/polym13111833

Abstract

Microbial fuel cells (MFCs) have attracted attention by directly converting the bioelectrochemical energy possessed by the organic materials that make up the biomass into electrical energy. In this study, the relationship between the biofilm formed on the titanium-based anode electrode surface, and the chemical composition of the substrate, the energy source of MFC, was investigated. For this, MFCs were made by using poplar wood shavings rich in organic material as the substrate, titanium-based material as the anode electrode, and natural soil as bacterial habitat. Three types of MFCs containing 1%, 10%, and 20% poplar wood shavings by weight were made and named P1-MFC, P2-MFC, and P3-MFC, respectively. According to electrochemical analysis, P3-MFC provided the highest open circuit voltage with 490 mV value, and the highest power density with 5.11 mW/m2 value compared to other MFCs. According to optical microscopy examinations, there were Bacillus and Coccus species of bacteria in the soil structure, and these bacteria also existed around the fiber of poplar wood shavings in MFCs. Scanning electron microscopy (SEM), energy-dispersive spectrum (EDS), and Fourier transform infrared spectroscopy (FTIR) analysis showed that MFCs formed biofilm in the titanium-based anode, and the chemical composition of this biofilm with poplar tree was similar. As a result, due to the catalysis reactions of bacteria, the titanium-based anode electrode surface was coated with polymer biofilm released from poplar wood shavings.

Highlights

Microbial fuel cells (MFCs) directly convert the bioelectrochemical energy of organic structures in biomass into electrical energy through to catalysis reactions of bacteria
Among MFCs containing different amounts of poplar wood shavings, the highest power density was achieved by the P3-MFC (5.11 mW/m2) with the highest amount of poplar wood shavings
This confirmed that Bacillus and Coccus species of bacteria decompose organic matter found in poplar shavings

Summary

Introduction

Microbial fuel cells (MFCs) directly convert the bioelectrochemical energy of organic structures in biomass into electrical energy through to catalysis reactions of bacteria. The electrical energy generation of MFC causes bacteria to form an organic biofilm layer, especially on the anode electrode surface [5]. More studies are needed on the properties of the biofilm layer formed on the electrode surfaces as a result of the reaction of rich polymer-containing substrate materials with bacteria and the effect of MFCs on electrical energy production performance. In order to address this question, in this study, we produced MFCs by using titaniumbased anode electrodes, graphite cathode electrodes, poplar shavings as substrate, and natural soil bacteria habitat. In these MFCs, only the substrate ratios are different from each other. The electrochemical performance of these MFCs and the organic structure of the biofilms formed on the titanium-based anode electrode surface were examined and explained

Materials

Methods

Electrochemical Performance of MFCs

Conclusions