| Due to growing environment-related problems and explosive growth in global energy demand,the development of sustainable energy materials and green nanotechnology for the construction of fuel cells,metal air cells and electrolytic water systems has attracted global attention.In particular,the zinc-air battery（ZAB）has proven to be a promising technology capable of meeting the needs of future energy conversion devices due to its widely recognized advantages of theoretical energy density to meet the needs,low cost,environmental friendliness,and reliable safety.The oxygen reduction reaction（ORR）during discharge and oxygen evolution reaction（OER）during charging are the key reactions in the whole rechargeable ZAB equipment.However,the slow kinetics of ORR and OER lead to adverse polarization losses,so effective catalysts to accelerate these reactions have been a central concern.Although noble metal materials,such as Pt-based catalysts and Ru O2,have long been considered as the benchmark for catalyzing ORR and OER,respectively,they have the disadvantages of single catalytic activity,high cost,and poor cyclic stability.In this context,it is of practical value to design an efficient and durable ZAB dual-function ORR/OER catalyst.Zeolite-imidazoles framework（ZIF）is one of the components of organometallic framework,which has excellent stability and chemical function.ZIF-derived transition metal carbon materials are favored due to their high specific surface area and high efficiency stability.Based on this,in this paper,ZIF-based material as precursor,through the appropriate chemical method etching,the introduction of phosphorus and doping metal technology to construct a series of high-performance catalysts,and oxygen reduction reaction（ORR）and oxygen precipitation reaction（OER）performance research and the application of zinc air battery research.The specific research content is as follows:1.Through the synthesis of ZIF precursor to carry out multi-doping engineering strategy,a high-performance catalyst with nitrogen/phosphorus co-doped carbon-based dodecahedron and iron-doped Co2P component constraints was successfully prepared.Phytic acid not only contributes to the formation of porous structure,but also acts as a phosphorus source to form corresponding metal phosphide and P doping characteristics in carbon matrix.Due to its unique composition and structure-dependent advantages,the microenvironment of the electrocatalyst is significantly regulated,thus promoting favorable local charge rearrangement and smooth mass/charge transfer processes in the electrocatalytic reactions involving oxygen.The results showed that the prepared catalyst has significantly enhanced reversible oxygen activity,and its ORR/OER potential difference is 0.655 V（half wave potential of oxygen reduction reaction is 0.895 V;Theηof oxygen evolution reaction is320 m V）,the assembled zinc air battery has a high specific capacity(762 m Ah/g Zn),and has excellent durability,more than most previous reports.2.By taking the new accordion type ZIF as the precursor,etching with potassium ferricyanide,the final Fe AC-SA-Ni SA@NC catalyst was obtained.Catalysts with bimetallic active sites usually exhibit further enhanced catalytic activity due to the synergistic interaction between adjacent metal atoms.The results showed that Fe AC-SA-Ni SA@NC catalyst has good catalytic activity for oxygen reduction and oxygen evolution reactions.Its excellent ORR activity is manifested in the half-wave potential of0.93 V in alkaline medium,and has good long-term stability in alkaline medium.In addition,the catalyst showed good OER performance.At the same time,the catalyst shows excellent performance in the assembled zinc-air batteries,with a peak density of 293 m W/cm2 and an energy density of 377m A/cm2,showing good specific capacity and excellent cycle stability.This work explores a new path for further development and utilization of high performance catalysts.Figure[53]Table[9]Reference[151]... |
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