Studies On The Reparation And Roperties Of Antibacterial Cathode Catalysts In Microbial Fuel Cells

As a green environmental protection technology with synchronous power output and sewage treatment,microbial fuel cell(MFC)is characteristic of low cost,and low residual sludge production,and realizes the synergetic process of production of electricity and degradation of pollutants,which is the focus of researchers in various countries.Single-chamber membraneless MFC has the advantages of small internal resistance and low cost.Therefore,single-chamber MFC is the most ideal configuration for the augmentative and industrialized application of MFC.However,there is a problem of cathode microbial contamination in the single-chamber MFC,resulting in decreasing of the productivity efficiency of single-chamber MFC.And the Pt/C as cathode catalyst is expensive,which restricts the industrialized application of the single-chamber MFC.Therefore,exploiting a new non-precious metal catalyst with the ability of anti-microbial contamination is extremely important for the development of MFC.The results show that the heteroatoms doping can improve the catalytic activity of oxygen reduction and the efficiency of power output.And introducing oxygen-containing functional groups into carbon materials can achieve the purpose of in situ antibacterial ability when serving as MFC cathode catalyst.Therefore,a novel template-like method is proposed for the preparation of core-shell material with high surface area,porosity and high catalytic performance.This material is consisted of conductive carbon black(CB)as the core,nitrogen doped graphene(NG)as the shell and hexadecyl trimethyl ammonium bromide as the bridge linking CB and NG.(1)Different material preparation methods,including template-like method,loading method and mechanical mixing method,were compared at first.The materials prepared by these methods were characterized by SEM,TEM,XRD,XPS and Raman spectroscopy,and the electrochemical properties of these three materials were tested by cyclic voltammetry,polarization curve,Tafel and other techniques.Results showed that only the materials prepared by the template-like method had the core-shell structure,and higher oxygen reduction and catalytic activity than the other two materials.Secondly,in order to further study the oxygen reduction and catalytic performance of the materials prepared by the template-like method,the effects of different mass ratios of graphene oxide(GO)and CB on the properties of materials were studied.According to the results of physicochemical and electrochemical characterization,it was clear that the oxygen reduction of the material was optimal when the mass ratio of GO/CB was 10:1,electron transfer number was 3.91±0.01.(2)this work also explored the stability and cost of NG@CB-10,and applied NG@CB-10,NG and Pt/C in the dual-chamber MFC to monitor the coulomb efficiency,COD removal efficiency,polarization curve and power density.It was found that that the NG@CB-10 material displayed slightly inferior power output to that of Pt/C.By taking into account of cost and catalysts loading,however,the NG@CB-10 was still expected to be promising cathode catalyst to replace Pt/C.(3)NG@CB-10,NG and Pt/C were use as cathode catalysts in single-chamber membraneless MFC.During the one-month running,CE,COD,polarization curve and power density were monitored to evaluate the cell performance.The content of protein was used for representing the biomass on cathode,which was measured on the basis of coomassie brilliant blue method.By analyzing the cell recession performance and cathode biomass,the NG@CB-10 displayed superior ability of antibacterial pollution,followed by NG and Pt/C.It is concluded that NG@CB prepared by the template-like method possesses excellent oxygen reduction activity and antibacterial performance.This work can provide a new method of synthesis of electrode for the industrial application of MFC.