Preparation And Performance Study Of Bimetallic Sulfide/carbon Microbial Fuel Cell Cathode

Microbial fuel cells?MFCs?are clean and renewable energy source.It degrades organic pollutants in wastewater and converts the chemical energy generated into electrical energy.This new battery technology enables energy to be recycled while treating sewage.Because MFCs are harmless to the environment and have certain environmental friendliness during operation,this characteristic has attracted widespread attention from researchers at home and abroad.It also provides a certain direction for people to develop new clean energy.It is found in the current research that MFCs will encounter problems such as poor stability and low power generation performance during operation.An oxygen reduction reaction occurs at the cathode of MFCs.The rate of the oxygen reduction reaction directly affects the performance of MFCs,so the activity of the cathode catalyst is the main factor limiting these problems.In this paper,two kinds of MFCs cathode catalysts were prepared on the premise of improving the performance of MFCs,enhancing the stability of operation and reducing the cost of cathode catalysts.The catalysts were characterized by X-ray diffraction?XRD?,X-ray photoelectron spectroscopy?XPS?,N₂adsorption-desorption isotherm?BET?,scanning electron microscope?SEM?,and transmission electron microscope?TEM?to analysis of structural and morphological features.Cyclic voltammetry?CV?,linear sweep voltammetry?LSV?,rotating disk electrode/rotating circular disk electrode?RDE/RRDE?and other electrochemical test methods were used to analyze the electrochemical performance of the catalysts.In the experiment,auricularia was used as the nitrogen-containing carbon source,and it was put into a mixed solution of ferric chloride,cobalt chloride and thiourea.Then put the mixed materials into the reaction kettle for hydrothermal reaction.After hydrothermal,the samples were carbonized at different temperatures to prepare?Co Fe?/Co₈Fe S₈/NSC-X?X=800,850,900,950?catalysts.Structure analysis and electrochemical performance comparison of the catalysts obtained at different carbonization temperatures.Co₈Fe S₈/NSC-900 has the largest power density(1.002 W m^-2),the highest output voltage?0.561V?and the smallest charge transfer resistance?27.33??when used as a cathode catalyst for MFCs.And it still maintains good stability after running for more than 1440h.Also using auricularia as a nitrogen-containing carbon source,we replaced ferric chloride with nickel nitrate and compounded with thiourea and cobalt chloride.Co Ni₂S₄/NSC-X?X=800,850,900,950?catalyst was obtained after high-temperature carbonization of the tube furnace.After structural analysis and electrochemical performance comparison,Co Ni₂S₄-900 has the maximum power density(0.96 W m^-2)compared to other temperature catalysts,and can run stably over 1440h.In this paper,the catalyst composed of black fungus and double transition metal sulfide is used as the cathode catalyst of MFC.It not only shows good stability and excellent electrocatalytic activity,but also has low material cost and is easy to obtain.The emergence of this material provides a new reference for solving the low stability performance of MFCs.