Research On The Performance Of Carbon Based Composites In Microbial Fuel Cells

At present,we are facing the problems that environmental pollution and energy demand are becoming more and more urgent.Many experts and scholars have focused their attention on new energy.Microbial fuel cells are new device which uses microorganisms as catalysts to convert chemical energy into electrical energy.The cathode can react with oxygen in the air.Compared with the anode,the electron transfer rate of the cathode is slower.Therefore,the cathode is an important factor affecting the performance of the microbial fuel cells.Now,Pt/C is widely used as cathode catalyst in microbial fuel cells cathode materials.The commercial application of microbial fuel cells is limited by Pt/C catalyst,due to that has the high cost,low storage and poor stability.Therefore,it is particularly important to find a cathode catalyst with low cost and good performance.Around the above content,the main contents of this paper are as follows.1.Using dicyandiamide as C source and N source,doping Fe and Co as transition metals,and calcining temperature as contrast conditions,the composite catalyst C-N-FeCo with Co and Fe alloy particles doped with carbon nanotubes was synthesized.By means of SEM and other characterization methods,it was found that Co and Fe elements were mainly located at the end of carbon nanotubes.Electrochemical tests were carried in 0.1M PBS solution,and the results showed that catalyst C-N-FeCo exhibited the good electrochemical properties.The initial potential of C-N-FeCo-850 is 0.83 V,which is very close to Pt/C catalyst which under the same conditions?0.9 V?.When applied to the microbial fuel cells cathode,the highest power density of C-N-FeCo-850 reached 1350 mW m^-2,which was 6.1 times higher than that of Pt/C catalyst(220 mW m^-2).2.Using acetylacetone organic metal salts as raw materials,dimethyllimidazole as C source and N source for doping,Fe and Co co-doped carbon nanosheets composite catalyst FeCo-C/N was prepared by temperature comparison.The catalyst FeCo-C/N in 0.1M PBS electrolyte exhibits high electrochemical performance.The starting potentials of FeCo-C/N-1000 and FeCo-C/N-1100 are very close to the Pt/C,which are 0.85 V,0.82 V and 0.9 V,respectively.The current density of FeCo-C/N-1000 is much higher than that of Pt/C catalyst.When the catalyst was modified in microbial fuel cells cathode,the catalyst FeCo-C/N-1000 showed the best power generation performance with a power density of catalyst up to 1250 mW m^-2,while that of Pt/C catalyst was 580 mW m^-2.3.Using biomass disposable chopsticks as C source,the cathode catalyst of N/PC was synthesized by introducing melamine for N doping at high temperature.Through a series of physical characterization methods,it can be known that catalyst N/PC is a porous carbon material with large specific surface area.The electrochemical measurements were carried out in neutral medium.The comparison between the N-doped carbon material?PC?and the N-doped carbon material?N/PC?resulted in the N/PC-1000 starting potential of 0.8V which was closest to the Pt/C catalyst.In the battery,the maximum power density of N/PC-1000 is 620 mW m^-2 and PC-1000 is500 mW m^-2,both of which are higher than the power density of Pt/C catalyst(190mW m^-2).