Investigation On Preparation Of Manganese Dioxide Composites And The Properties Of The Charge Storage In Microbial Fuel Cells

Microbial fuel cell?MFC?was a kind technology that can deal with organic pollutants in sewage,and simultaneously produce electric energy.The performance of microbial fuel cells was determined by the microbial activity of the anode surface,while the anode material of MFC played a very important role in microbial activity.In this paper,the preparation,compound and application in MFC of manganese dioxide modified anode were studied,and the power and energy storage performance of MFC were further improved.Manganese dioxide?MnO₂?was synthesized via hydro-thermal method on carbon felt?CF?,and the whole entity functions as anode of MFC.And the deposition time,water thermal temperature and other variables were controlled,and CF/MnO₂electrode was obtained under optimal conditions.The optimal ratio of Carbon felt/Polyaniline electrode was prepared by chemistry methode.CF/MnO₂ and CF/PANI and CF electrodes were utilized to cultivate microorganism as anode in MFC.In our study,the maxinum power output of MFC using CF/MnO₂ electrode,CF/PANI electrode,and CF electrode as bioanode reached 7.89 W/m³,5.42 W/m³,and 3.73 W/m³,respectively.The high electric produced of CF/MnO₂ electrode were9229.8 C/m²,which was 1.51 times and 3.16 times as big as CF/PANI electrode and CF electrode,when the cell was charged for 60 minuites and discharged for 60minuites.The cathode of CF/MnO₂ modified MFC was used to reduce hexavalent chromium pollutant.MFC was operated under intermittent conditions and the removal rate of hexavalent chromium was 69.92%in 4 h.The resistance of manganese dioxide composite was reduced by the intermediate layer of conductive polyaniline and the compound material of CF/MnO₂/PANI/MnO₂was prepared.In EIS tests,the electrode electron transfer impedance Rct of CF/MnO₂/PANI/MnO₂ was smaller?3.41??than that of CF/MnO₂.The addition of the middle layer of PANI made the composite electrode impedance smaller,indicating that the PANI/MnO₂ modified electrode was good for electron transport and had good reversibility.The storage capacity of CF/MnO₂/PANI/MnO₂ electrode was increased by 1961.1 C/m² compared to CF/MnO₂ electrode,when the cell was charged for 60minuites and discharged for 60 minuites.MFC was operated under intermittent conditions and the removal rate of hexavalent chromium was 75.81%in 4 h.By combining the carbon nanotubes with polyaniline and manganese dioxide,the CF/N-CNT/PANI/MnO₂ composite electrodes were prepared by electrodepositing and hydrothermal method in two different methods.The storage capacity of CF/N-CNT/PANI/MnO₂ electrode was 2492.8 C/m²,much higher than that of CF/MnO₂/PANI/MnO₂ electrode,when the cell was charged for 60 minuites and discharged for60 minuites.MFC was operated under intermittent conditions and the removal rate of hexavalent chromium was 79.81%in 4 h.In this paper,preparation of large pore network structure,high porosity,and high ratio of surface area sponge matrix and S/N-CNT/PANI/MnO₂ composite electrode was prepare.The maximum power density of MFC was 12.07 W/m³.The total discharge and storage capacity of S/N-CNT/PANI/MnO₂ anode were 1798 C/m² and190 C/m² respectively,which were 3.82 times and 6.89 times as big as CF electrode,when the cell was charged for 5 minuites and discharged for 10 minuites.These data show that S/N-CNT/PANI/MnO₂ electrode had better energy production and energy storage performance.