Performance Study Of Selenide/biomass Carbon Microbial Fuel Cell Cathode

Microbial fuel cells?MFCs?are devices that can simultaneously output electrical energy while effectively treating organic pollutants in wastewater.Due to its environmental friendliness,it has attracted widespread attention from many researchers at home and abroad.It provides a new direction for environmental issues and structural transformation of energy.MFCs use the organic waste in the waste water as the microbial nutrient,and use the process of producing organic matter by the electricity-producing microorganisms to realize the conversion of chemical energy to electric energy,and realize the purpose of sewage treatment in the process of conversion.At present,an important limiting factor for the practical application of MFCs is their low efficiency in cathodic oxygen reduction.The cathode oxygen reduction reaction is the key to its electricity production performance,so an effective method to improve the electricity production efficiency of MFCs is to find a highly efficient and inexpensive cathode catalyst.This paper describes two low-cost,highly efficient and easily produced MFCs cathode oxygen reduction catalysts.The catalysts were characterized by X-ray diffractometry?XRD?,X-ray photoelectron spectroscopy?XPS?,N₂ adsorption/desorption(S_BET),scanning electron microscopy?SEM?,and Transmission electron microscopy?TEM?.Electrochemical activity such as linear sweep voltammetry?LSV?,cyclic voltammetry?CV?,rotating disk electrode?RDE?and rotating circular disk electrode?RRDE?were used to test the electrochemical activity and analyze its catalysis.The experiment uses biomass corn stover as a catalyst carbon source,which not only realizes the reuse of waste,but also reduces the material cost of the catalyst.The small amount of nitrogen-doped straw was immersed in a mixed solution of selenium powder and ferric chloride.The evaporation induced self-assembly and one-step carbonization were used to successfully prepare Fe₃Se₄/FeSe/NPGC-x?x=800,850,900,950?catalyst under the control of hydrazine hydrate.In the experiment,the effects of different carbonization temperatures on the structure and properties of the materials were compared,and the relationship between catalyst activity and temperature was further studied.The Fe₃Se₄/FeSe/NPGC-850 sample has the largest power density(1003mW m^-2)and the smallest charge transfer internal resistance?25.07??as the MFCs cathode,and shows good stability during the 120-day simulation run with a stable voltage output.Also using corn stalk as a carbon source,we chose a combination of Co and the Se which are also transition metals,and introduced cobalt chloride hexahydrate as a cobalt source.The Co_0.85Se/NPGC-x?x=800,850,900,950?composite material was prepared by high temperature carbonization of the tube furnace.After a series of electrochemical and MFCs performance characterization tests,Co_0.85Se/NPGC-900 samples have higher oxygen reduction catalytic activity than samples prepared at other temperatures.And it can still maintain a fairly high stability during continuous operation.After 90 days of simulation,the power density reduction rate was only 11%,and the output voltage dropped only 6.4%.The transition metal selenide catalyst prepared by using corn stalk as carbon source has not only high electrocatalytic activity,but also low cost and easy availability of raw materials,and has been recycled and reused,and has a wide application prospect.The appearance of this material provides a new reference for the study of MFCs cathode catalysts and the practical application of MFCs.