The Synthesis Of Carbon Based Cathode Materials For Microbial Fuel Cells Applications

With the development of the society,energy crisis and environmentdeterioration are the most urgent issues that have stimulated strong demands for the development of novel energy techniques.As a new-style device,microbial fuel cells?MFCs?are different from traditional fuel cells,showing two-function of electrogenesis and pollutant degradation through the catalyzing of microorganisms on the anode.Recently,MFCs have witnessed rapid development owing to their unique advantages.However,there are still remaining some problems associated with the cathode,especially,high-cost,limited catalytic activity and low stability.Conventional cathode catalysts are based on the noble metal and its alloys,but suffer from their high-cost,scarcity and instability catalytic activity.Therefore,replacing the noble catalyst with low-cost and high efficient oxygen reduction reaction?ORR?catalysts are of great significance for the development of MFCs.In this work,several carbon nanomaterials based metal compounds were successfully prepared by using the hydrothermal method,chemical bath deposition,Hummer's method,template method and thermal reduction method.Accordingly,the ORR properties and MFCs performance were investigated systematically.Concrete research contents are as follows:?1?CuSe@CNTs composites were successfully synthesized through facile hydrothermal method.The as-prepared materials exhibit superior ORR performance and catalytic capacity in MFCs cathode.The maximum output power can reach 426±5 mW m-2,which can be mainly attributed to the following aspects: carbon nanotubes overcome the semiconductorproperty of CuSe,and the CuSe nanoparticles?NPs?enhance the exposure of active sites.?2?CuSe@rGO-CNTs composites with three-dimensional layered structure were synthesized by Hummer's and hydrothermal methods.Compared with the CuSe@rGO and CuSe@CNTs,CuSe@rGO-CNTs displayed superior ORR performance and catalytic capacity in MFCs cathode.The maximum output power can reach 504±5 mW m-2,which can be mainly attributed to the efficient space of three-dimensional layered structure for the transmission of electron and proton.At the same time,the introduction of CNTs can masterly avoid the aggregation of graphene sheets and hold the inherent large surface area for the improved ORR catalytic activity.?3?The HCN-Co₃O₄ composites were prepared by carbonization of phenolic resin,chemical bath deposition and annealing methods.Such combination of nitrogen doped carbon and cobalt oxides was able to improve the performance of ORR,and the maximum output power can reach 553 ± 10 mW m-2.On the one hand,nitrogen doping carbon material can increasethe active sites significantly.On the other hand,carbon material can overcome the semiconductor nature of Co₃O₄.Besides,the hollow sphere structure more likely enhance the surface area and provide more chance for the touch of oxygen and electron.?4?The PGN-Co₃O₄ materials were successfully synthesized by Hummer's,chemical bath deposition and thermal reduction methods.The porous graphene was prepared by template method,which masterly avoid the aggregation of graphene sheets and nitrogen dopant not only provide many anchoring point for the cobalt oxides,but also enhance the combination of Co₃O₄ and graphene.the maximum output power can reach 578±10 m W m-2.