scholarly journals Enhancement of the Start-Up Time for Microliter-Scale Microbial Fuel Cells (µMFCs) via the Surface Modification of Gold Electrodes

Micromachines ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 703
Author(s):  
Begüm Şen-Doğan ◽  
Meltem Okan ◽  
Nilüfer Afşar-Erkal ◽  
Ebru Özgür ◽  
Özge Zorlu ◽  
...  
Keyword(s):  
Surface Modification ◽  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Microelectromechanical Systems ◽  
Electrochemical Impedance ◽  
Shewanella Oneidensis ◽  
Bacterial Attachment ◽  
Anode Surface ◽  
Sem Images ◽  
Start Up

Microbial Fuel Cells (MFCs) are biological fuel cells based on the oxidation of fuels by electrogenic bacteria to generate an electric current in electrochemical cells. There are several methods that can be employed to improve their performance. In this study, the effects of gold surface modification with different thiol molecules were investigated for their implementation as anode electrodes in micro-scale MFCs (µMFCs). Several double-chamber µMFCs with 10.4 µL anode and cathode chambers were fabricated using silicon-microelectromechanical systems (MEMS) fabrication technology. µMFC systems assembled with modified gold anodes were operated under anaerobic conditions with the continuous feeding of anolyte and catholyte to compare the effect of different thiol molecules on the biofilm formation of Shewanella oneidensis MR-1. Performances were evaluated using polarization curves, Electrochemical Impedance Spectroscopy (EIS), and Scanning Electron Microcopy (SEM). The results showed that µMFCs modified with thiol self-assembled monolayers (SAMs) (cysteamine and 11-MUA) resulted in more than a 50% reduction in start-up times due to better bacterial attachment on the anode surface. Both 11-MUA and cysteamine modifications resulted in dense biofilms, as observed in SEM images. The power output was found to be similar in cysteamine-modified and bare gold µMFCs. The power and current densities obtained in this study were comparable to those reported in similar studies in the literature.

Effect of Anode Surface Roughness on Power Generation in Microbial Fuel Cells

2012 ◽  
Author(s):  
Zhou Ye ◽  
Junbo Hou ◽  
Michael W. Ellis ◽  
Bahareh Behkam
Keyword(s):  
Surface Roughness ◽  
Fuel Cells ◽  
Glassy Carbon ◽  
Microbial Fuel Cells ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Electrode System ◽  
Anode Surface ◽  
Transfer Resistance ◽  
Rough Electrode

A three-electrode system was used to study the effect of anode surface roughness on the performance of microbial fuel cells (MFCs). Two glassy carbon plates were polished to uniform roughness of the orders of magnitude of 10s of nm and 100s of nm. Atomic force microscopy (AFM) was used to quantify the roughness as well as the 3D topography of the surfaces. Multiple electrochemical methods including potentiostatic tests, potentiodynamic tests, and electrochemical impedance spectroscopy (EIS) were utilized to monitor the performance of the glassy carbon electrodes. After 275 hours of experimentation, the current density generated by the rough electrode was much higher than that generated by the smooth one. Furthermore, the charge-transfer resistance of the rough electrode was lower than that of the smooth one. The better electrochemical performance of the rough surface may be due to denser biofilm grown on the surface, which was observed by scanning electron microscopy (SEM).

scholarly journals Adding Zero-Valent Iron to Enhance Electricity Generation during MFC Start-Up

2020 ◽  
Vol 17 (3) ◽  
pp. 806 ◽  
Author(s):  
Chao Li ◽  
Kang Zhou ◽  
Hanyue He ◽  
Jiashun Cao ◽  
Shihua Zhou
Keyword(s):  
Microbial Fuel Cells ◽  
Electricity Generation ◽  
High Throughput Sequencing ◽  
Electrochemical Impedance ◽  
Impedance Analysis ◽  
Zero Valent Iron ◽  
Sequencing Analysis ◽  
Sem Images ◽  
Oxidation Reduction ◽  
Start Up

The low power generation efficiency of microbial fuel cells (MFCs) is always a barrier to further development. An attempt to enhance the start-up and electricity generation of MFCs was investigated by adding different doses of zero-valent iron into anaerobic anode chambers in this study. The results showed that the voltage (289.6 mV) of A2 with 0.5 g of zero-valent iron added was higher than the reference reactor (197.1 mV) without dosing zero-valent iron (A4). The maximum power density of 27.3 mW/m2 was obtained in A2. CV analysis demonstrated that A2 possessed a higher oxidation–reduction potential, hence showing a stronger oxidizing property. Meanwhile, electrochemical impedance analysis (EIS) also manifested that values of RCT of carbon felts with zero-valent iron supplemented (0.01–0.03 Ω) were generally lower. What is more, SEM images further proved and illustrated that A2 had compact and dense meshes with a hierarchical structure rather than a relatively looser biofilm in the other reactors. High-throughput sequencing analysis also indicated that zero-valent iron increased the abundance of some functional microbial communities, such as Acinetobacter, Ignavibacteriales, Shewanella, etc.

scholarly journals Lack of Electricity Production by Pelobacter carbinolicus Indicates that the Capacity for Fe(III) Oxide Reduction Does Not Necessarily Confer Electron Transfer Ability to Fuel Cell Anodes

2007 ◽  
Vol 73 (16) ◽  
pp. 5347-5353 ◽  
Author(s):  
Hanno Richter ◽  
Martin Lanthier ◽  
Kelly P. Nevin ◽  
Derek R. Lovley
Keyword(s):  
Electron Transfer ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Microbial Fuel Cells ◽  
Electron Donors ◽  
Rrna Genes ◽  
Anode Surface ◽  
Oxide Reduction ◽  
Fuel Cell Anodes

ABSTRACT The ability of Pelobacter carbinolicus to oxidize electron donors with electron transfer to the anodes of microbial fuel cells was evaluated because microorganisms closely related to Pelobacter species are generally abundant on the anodes of microbial fuel cells harvesting electricity from aquatic sediments. P. carbinolicus could not produce current in a microbial fuel cell with electron donors which support Fe(III) oxide reduction by this organism. Current was produced using a coculture of P. carbinolicus and Geobacter sulfurreducens with ethanol as the fuel. Ethanol consumption was associated with the transitory accumulation of acetate and hydrogen. G. sulfurreducens alone could not metabolize ethanol, suggesting that P. carbinolicus grew in the fuel cell by converting ethanol to hydrogen and acetate, which G. sulfurreducens oxidized with electron transfer to the anode. Up to 83% of the electrons available in ethanol were recovered as electricity and in the metabolic intermediate acetate. Hydrogen consumption by G. sulfurreducens was important for ethanol metabolism by P. carbinolicus. Confocal microscopy and analysis of 16S rRNA genes revealed that half of the cells growing on the anode surface were P. carbinolicus, but there was a nearly equal number of planktonic cells of P. carbinolicus. In contrast, G. sulfurreducens was primarily attached to the anode. P. carbinolicus represents the first Fe(III) oxide-reducing microorganism found to be unable to produce current in a microbial fuel cell, providing the first suggestion that the mechanisms for extracellular electron transfer to Fe(III) oxides and fuel cell anodes may be different.

Reducing start-up time and minimizing energy losses of Microbial Fuel Cells using Maximum Power Point Tracking strategy

2014 ◽  
Vol 269 ◽  
pp. 403-411 ◽  
Author(s):  
Daniele Molognoni ◽  
Sebastià Puig ◽  
M. Dolors Balaguer ◽  
Alessandro Liberale ◽  
Andrea G. Capodaglio ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Maximum Power Point Tracking ◽  
Energy Losses ◽  
Maximum Power Point ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Start Up ◽  
Power Point ◽  
Tracking Strategy
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