Study On Modified Electrodes And Electrical Performance Of Microbial Fuel Cell

Microbial fuel cells are advanced device which uses microorganisms as catalysts to convert chemical energy into electrical energy.Microbial fuel cells?MFCs?have been recognized as an encouraging and challenging technology in saving energy and simultaneous wastewater treatment,overcoming environmental problems,supplied with biosensors,bio-hydrogen production,as well as in-situ power sources for bioremediation.The research and utilization of MFCs are still in the initial stage,and the low output power and high cost are the main problems hindering the commercialization of MFCs.Around the above issues,the detailed research contents of this thesis are as follows.?1?The MnO₂ modified electrode was used as anode in single-chabmer MFC.Firstly,MnO₂ nanosheets were synthesized by hydrothermal method.The result of SEM and other characterization methods show that the MnO₂ nanosheets have good crystallization performance,it was found to be a nanosheet structure with good crystallization performance and many nanowires wrapped on the surface.N₂isothermal adsorption curve showed that MnO₂ has larger specific surface area(35.47 m² g^-1).Furthermore,MnO₂ was compounded with carbon cloth and applied to the microbial fuel cell anode for electrochemical measurements test,the maximum power density of MnO₂@CC is 21.79 mW m^-2.The maximum power density is increased by 188.49%with the unmodified anode.?2?This study revealed Galla chinensis?gallnut?extraction was used as anatural catalyst to increase the electrical power output of two-chamber MFC.The active components extracted from gallnut were tannic acid?TA?and gallic acid?GA?.HPLC test show that the content of TA and GA increased as the extraction temperature increased,and the gallic acid reached 471.27 mg L^-1 at 85?.In addition,electrochemical analysis showed that the addition of GWE significantly promoted the generation of MFCs,the maximum power density is 67.77 mW m^-2 at 1000 mg L^-1.Compared with other herbal extract,GWE owned not only the most abundant content of antioxidants,but also could significantly stimulate the power generation of MFCs.?3?This study quantitative evaluation upon bioenergy-stimulating capabilities of EP and DA were clearly revealed via MFC modules.This work clarified redox-mediating characteristics of epinephrine?EP?and dopamine?DA?with other substance and suggested possible mechanisms of bioenergy-driven responses to organisms.Compared to vitamin B₂?VB?,vitamin C?VC?and gallic acid?GA?,both EP and DA as ESs significantly exhibited stable and reversible redox potential peaks in cyclic voltammetry.Evidently,power density performances of MFCs supplemented with EP and DA considerably increased ca.127%–385%,the maximum electrical power density was 54.57±0.23 mW m^-2 and 41.34±0.66 mW m^-2,suggesting that DA and EP would be the most appropriate electron shuttles?ESs?to effectively stimulate electron-mediating capabilities in multicellular organisms.