Study On Power Generation And Decolorization Performance Of Polypyrrole Composites In Microbial Fuel Cells

Microbial fuel cell(MFC)as a clean energy technology has the unique advantages of degrading wastewater and producing electricity simultaneously,which has attracted widespread attention from researchers.Anode of MFC,as a place for microorganisms to attach and reproduce,is the most critical factor affecting MFC's power generation performance and wastewater degradation efficiency.In this paper,the preparartion,compound and application in MFC of Polypyrrole modified anode are studied.Electricity generation and azo dye decolorization performance of composites in MFC are investigated.A polypyrrole/graphene aerogel composite electrode(PPy/GA/CB)was prepared using a carbon brush(CB)as a matrix.SEM tests showed that the material has a highly three-dimensional macroporous structure,which can provide a lot of space for microbial attachment.The maximum power density output of MFC using PPy/GA/CB electrode as bioanode reached2.07 W/m²,which is 1.51 times and 1.18 times that of CB anode MFC and GA/CB anode MFC.The stored charge of PPy/GA/CB anode MFC is 4095 C,when the cell is charged for 45 min,which is 1.75 times that of GA/CB anode MFC.High-throughput sequencing technology revealed that PPy/GA/CB anode biofilm colonies are more diverse than GA/CB.The dominant strains of both are Bacteroides and Proteobacteria,which account for 15.29%and 39.62%of the PPy/GA/CB anode biofilm and 46.02%and 17.63%of GA/CB anode biofilm,respectively.The decolorization rate of PPy/GA/CB anode MFC for Congo red in 44 h reach80.86%,which is 1.33 times and 1.09 times that of CB and GA/CB anode MFC.Utilizeing the CB as the matrix and pyrrole monomer as a reducing agent,a Polypyrrole-graphene hydrogel electrode(PPy-GH/CB)was prepared by a simple one-step method.This electrode has a highly three-dimensional porous structure,and polypyrrole could be uniformly dispersed on the surface of graphene.When this electrode is utilized as the MFC anode,the maximum power density reaches 1.92 W/m²,which is 1.4 times that of the CB anode MFC.In the stored charge performance test,when charged for 45 minutes,the stored power reached3948 C.In the study of methyl orange decolorization,the decolorization rate will decrease as the initial concentration of methyl orange increases,but the amount of decolorization unit time will increase.In the process of simultaneous decolorization,when the initial concentration of methyl orange is relatively low,MFC still has good power generation performance.Using stainless steel mesh(SS)as the matrix,Polypyrrole Hydrogel Electrode(PPy/SS)and Polypyrrole-Manganese Dioxide Hydrogel Electrode(PPy-MnO₂/SS)electrodes were prepared.SEM results show that the composite of manganese dioxide can reduce the particle size of polypyrrole particles.When SS,PPy/SS,and PPy-MnO₂/SS are used as MFC anodes,the maximum power density of the battery is 0.19 W/m²,2.46 W/m²,2.77 W/m²,respectively.When charged for 45 minutes,the stored charge of the PPy-MnO₂/SS anode is 1.29 times that of the PPy/SS anode.PPy-MnO₂/SS anode MFC was used to decolorize Congo red with different initial concentrations,and the decolorization rate decreased as the initial concentration of Congo red increased.