Preparation Of Air Cathode Catalyst For Microbial Fuel Cell And Study On Its Electricity Generation Performance

The massive increase in the global population,the increasing depletion of energy and the adverse effects of the use of fossil fuels have had a serious impact on global environmental anomalies and human health.On the other hand,the rapid development of industrialization and the demand for new technologies have caused various kinds of pollution to the environment,especially water pollution.However,none of the conventional wastewater treatment technologies can extract the large amounts of chemical energy captured in wastewater.Microbial fuel cells（MFCs）,however,can extract the chemical energy of organic pollutants in wastewater into electricity by means of bioelectric catalytic reaction.However,the slow kinetics and high production cost of MFCS cathode oxygen reduction are the main reasons for its large-scale application.As a result,it is essential to research and develop high efficiency,low cost and simple cathode catalyst in MFCS to catalyze the cathode oxygen reduction reaction and reduce the production cost.Metal organic framework（MOFs）and its derivatives stand out as cathode Oxygen Reduction Reaction（ORR）catalysts due to their high specific surface area,abundant pore structure and controllable properties.Therefore,in this paper,based on MOFs as precursors,which themselves provide carbon and nitrogen sources,the metal-nitrogen-carbon cathode ORR catalyst was obtained by means of high temperature calcination,multi-dimensional composite and metal element doping.The electrocatalytic activity of the prepared catalyst in oxygen reduction process and its application in microbial fuel cell were systematically studied.The specific content is as follows:（1）The precursors of ZIF-67/CNTs were synthesized with 2-methylimidazole and Carbon nanotubes（CNTs）by a simple solvothermal method with Co²⁺as the central metal ion.After pyrolysis at 800 ^oC,Co-N/CNTs nanocomposites doped with metal cobalt and nitrogen were obtained.Co-N/CNTs catalysts are beneficial to ORR reaction because of their metal-nitrogen-carbon structure,which effectively enriches the active sites of the catalysts.The carbon structure with high specific surface area can provide favorable conditions for charge transfer.Therefore,the Co-N/CNTs catalyst exhibited good catalytic activity in ORR reaction,the maximum power density obtained is 1029 m W m^-2.（2）Ni-MOF with three-dimensional columnar structure was synthesized by a simple hydrothermal method with Ni²⁺as the central ion,terephthalic acid and 1,4-diazide bicyclic[2.2.2]octane as the organic ligand.And ransition metal Co was introduced into the three-dimensional structure in the meantime,and Ni/Co-NC catalyst was prepared by high temperature pyrolysis.Using the synergistic interaction between Ni and Co bimetals and the three-dimensional porous structure formed,the catalyst has good ORR catalytic activity.Using Ni/Co-NC as MFCS cathode catalyst,the maximum power density obtained is 872 mWm^-2.