Preparation Of Heteroatom-Doped Carbon Nano Catalysts And Its Performance Research Of Oxygen Reduction Reaction

Microbial fuel cell?MFC?is a newly arising technology that could generate electricity from organic matters when degrading organic substance.The characteristics of cathode has been regarded as one of the key factors to influence the performances of MFC.Searching for new type cathodic catalysts for oxygen reduction reaction has attracting great attention,which has important significance to promote practical and expansion of MFC.This Study has been carried out based on the heteroatom-dope carbon nano materials oxygen reduction reaction,synthesize iron and nitrogen doped carbon nanotubes/particle complexes,nitrogen doped graphene,biomass self-doped mesoporous carbon nano,three new types of oxygen reduction catalysts.The product characteristic,electrochemical function and the performance of oxygen reduction reaction?ORR?were analyzed via MFC.The results are as followed:?1?Using chemical vapor deposition to synthesize iron and nitrogen doped carbon nanotubes/particle complexes FeNCB?Black Pearls 2000 as carbon source precursors?and FeNCC?acetylene black as carbon source precursors?.The product characteristic,electrochemical function and ORR was analyzed.The transmission electron microscope,X ray photoelectron spectroscopy and X-ray diffraction as well as Raman investigation revealed that the FeNCB has smaller carbon nano tube diameter,and the ratio of pyridine nitrogen and graphitic nitrogen of FeNCB was higher.Duing to heteroatom-doped,the carbon tube structure was destroyed,and then has more oxygen adsorption sites.Besides,the cyclic voltammogram and rotating ring-disk electrode tests showed that the FeNCB potential for oxidation reduction peak is greater than that of the FeNCC and Pt/C?20%?,and the electron transfer number of FeNCB was nearly four-electron pathway?377?3.97?.In addition,the catalyst was prepared as MFC cathode,the results show that the max power density of MFC-FeNCB reached 1212.8 mW·m^-2 higher than that of MFC-Pt/C?20%?(794.1 mW·m^-2),and much higher than that of MFC-FeNCC(362.4 mW·m^-2).The raw material cost of FeNCB was 5.76 $·g^-1,and the yields of FeNCB was 34.36%.Therefore,FeNCB can be used as a new option for expansion of MFC.?2?Nitrogen-doped graphene?NGs?was synthesized by two step method.The product characteristic,electrochemical function and ORR was analyzed.The transmission electron microscope,X-ray diffraction and Raman as well as X ray photoelectron spectroscopy investigation revealed that the prepared material appeared wrinkled gauze structure,the layer spacing of NG950_7.5/2.5/0.8?the proportion of urea,melamine,and glucose was 7.5:2.5:0.8,annealing temperature for 950 0C?was largest.ID/IG ratio of NG950_7.5/2.5/0.8 was the smallest?1.01?,the content of pyridinic nitrogen and graphitic nitrogen of NG950_7.5/2.5/0.8 was higher than other NGs.Besides,electrochemical detections as cyclic voltammogram and rotating ring-disk electrode tests showed that the potential of oxygen reduction peak and electron transfer number of NG950_7.5/2.5/0.8 were 0.01V and 3.77?3.96 via an around four-electron pathway.In addition,the catalyst was prepared as MFC cathode,the results show that the max power density of MFC-NG950_7.5/2.5/0.8 reached 598.0 mW·m^-2.The cost of raw materials for preparation of NG950_7.5/2.5/0.8 was only 0.34 $·g^-1,and the productivity reached 9.26%.Therefore,NG950_7.5/2.5/0.8 could realized high efficiency,low cost and high stability for MFC cathode catalytic oxygen reduction.?3?Using egg as the biomass carbon source,g-C₃N₄ as raising agent,with one step way to synthesize biomass self-doped mesoporous carbon nano catalyst EGCs.The transmission electron microscope,X-ray diffraction as well as Brunner-Emmett-Teller method investigation revealed that EGCs appeared wrinkled gauze structure,and the contrast EC was appearing massive structure,the surface area of EGCs was lager than EC 10?20 times.X ray photoelectron spectroscopy analysis that the content of pyridinic nitrogen and graphitic nitrogen of EGC1-10-2(g-C₃N₄:egg=1:1,heating rate of 10?·min^-1,annealed 2 h)was highest?0.59?.Besides,electrochemical detections as cyclic voltammogram and rotating ring-disk electrode tests showed that the potential of oxygen reduction peak of EGC1-10-2 was 0.10V,and electron transfer number of that was 3.84-3.92,which indicated that EGC1-10-2 via an around four-electron pathway.The maximum power density of MFC-EGC1-10-2 was 737.1 mW·m^-2 higher than MFC-Pt/C?20%?704 mW·m^-2,The cost of raw materials for preparation of was only 0.049 $·g^-1,and the productivity reached 20.26%.The low cost,high yield and high performance of EGC1-10-2 can be used for MFC expansion.