Study On The Performance Of Iron Phosphide/carbon Composite Microbial Fuel Cell Cathode

Microbial fuel cells?MFCs?as a combination of organic wastewater treatment and microbial power generation technology has good prospects for the application of green energy system.MFCs technology can realize the conversion of the chemical energy contained in the pollutants directly convert to electrical energy during the completion of the treatment of the organic wastewater,and further produce electricity.However,a series of problems such as high cost of cathode catalytic material?such as commercial Pt/C?in MFCs and low catalytic performance?output power?,the application of MFCs is limited.Based on this,the dissertation focuses on the research of MFCs cathodically catalyzed materials,and selects carbon-based composite catalyzed materials that are inexpensive,stable,and have good electrocatalytic properties,thereby improving the electrical production performance of MFCs.In this study,hydrated ferric chloride as iron source,diammonium hydrogen phosphate as phosphorus source,peeled corn stalks and melamine as the carbon source of different composites,respectively,have been prepared two kinds of air cathode microbial fuel cell cathode catalytic composite.The microstructure and mechanical properties of the composites are characterized by X-ray powder diffraction?XRD?,Fourier transform infrared spectroscopy?FT-IR?,X-ray photoelectron spectroscopy?XPS?,specific surface area?BET?,scanning electron microscopy?SEM?,transmission electron microscopy Voltammetry?CV?,linear sweep voltammetry?LSV?,alternating current impedance test?EIS?,rotating disk electrode?RDE?and other physical and chemical characterization methods and electrochemical test analysis methods,the compositional content,crystallinity and topography of the prepared composite material are investigated,and the oxygen reduction kinetics process inside the cathode material of the microbial fuel cell is analyzed.The specific research results are as follows:?1??Fe?PO₃?₃?/FeP partly-graphitized carbon??Fe?PO₃?₃?/FeP/PGCs?composites are prepared at the optimum conditions of iron and phosphorus addition ratio?molar mass ratio of 1:1?and the optimum calcination temperature?900??composites reach a maximum output power density of 1.162±0.022 W·m^–2,the COD removal efficiency could reach 92.13%,the coulombic efficiency?CE?could reach 23.02%and the stability is good.The maximum power density decreases only 4.56%.Due to the presence of many FeP active sites in Fe?PO₃?₃/FeP/PGC-900,in addition,synergy between the Fe?PO₃?₃/FeP heterojunction and the oxygen containing functional groups on the carbon substrate can effectively enhance the cathode composite catalytic activity.?2?N-doped Fe₂P partly-graphitized carbon?Fe₂P/NPGC?composite is prepared with Fe₂P/NPGC as cathode under the conditions of the best iron,phosphorus and carbon addition ratio?molar mass ratio 2:1:8?and the optimum calcination temperature?850??.The maximum output power density reach 1.050±0.012 W·m^–2.There are more Fe₂P nanoparticles to provide more active sites for the oxygen reduction reaction and enhance the performance of the composite catalytic material.