Controllable Synthesis Of Metalloporphyrin/C₆₀ Supramolecular Structure And Electrocatalytic Performance Of Derived Carbon Materials

Fullerenes are a class of zero-dimensional spherical molecules with aπ-conjugated structure,which have potential applications in the fields of organic photovoltaics,energy storage,biomedicine and catalysis,etc.Fullerene molecules are self-assembled or co-assembled with otherπ-conjugated molecules to obtain micro-nano structures with specific morphology,size and high crystallinity,which can improve the properties of fullerenes and is of great significance for their practical application.Metalloporphyrins exhibit excellent electrocatalytic activity for oxygen reduction and can form supramolecular structures with fullerenes through theπ-πinteraction between molecules.Therefore,the controllable synthesis of metalloporphyrin/fullerene supramolecular structure to construct a one-dimensional,two-dimensional or three-dimensional supramolecular structure,and then directly convert it into a porous carbon material that maintains the original morphology will help improve their electrocatalytic performance.As a starting point,a series of tetraphenylporphyrin nickel（cobalt）/C₆₀ supramolecular structures were synthesized by liquid-liquid interface deposition in this paper.Fullerene-derived porous carbon materials were also prepared by pyrolysis and their applications in electrocatalysis and zinc-air batteries were explored.The main research content and research results are summarized as follows:（1）Eight solvents such as toluene were used as good solvents and seven solvents such as methanol were used as bad solvents.The relationship between the solvents and the morphology and structure of tetraphenylporphyrin nickel（cobalt）/C₆₀ crystals in liquid-liquid interface deposition method was systematically studied.The results show that good solvents can enter the crystal structure of tetraphenylporphyrin nickel （cobalt）/C₆₀ to form solvated structure,and different good solvents can cause different co-assembly processes of tetraphenylporphyrin nickel（cobalt）and C₆₀, which ultimately determines the morphology and structures of the crystal of tetraphenylporphyrin nickel（cobalt）/C₆₀.It is proved that the good solvent doping is the key factor to determine the morphology and structure of tetraphenylporphyrin nickel（cobalt）/C₆₀ crystal.It also provides a reference basis for further exploration of the application of the tetraphenylnickel（cobalt）porphyrin/C₆₀ supramolecular structure,and enriches the database of the relationship between the tetraphenylnickel （cobalt）porphyrin/C₆₀ crystal morphology and the solvent.（2）The tetraphenylporphyrin nickel（cobalt）/C₆₀ supramolecular structure was treated by high temperature pyrolysis method,resulting in a series of porous carbon materials derived from fullerenes,which showed excellent electrocatalytic activity for oxygen reduction reaction and oxygen evolution reaction.The excellent electrocatalytic activity is mainly attributed to two aspects:on the one hand,a large number of mesoporous and structural defects formed in the pyrolysis materials are conducive to exposing more active sites,and the mesoporous and structural defects also create conditions for mass transfer and electron transfer;On the other hand,the presence of Co or Ni and the formation of pyridine nitrogen and graphite nitrogen during pyrolysis enhance the electrocatalytic activity of the materials.It was found that the CoTPP/C₆₀-800 catalyst prepared at 800℃exhibited the best electrocatalytic performance,with an oxygen reduction reaction（ORR）initial potential of 0.91V and a half-wave potential of 0.824 V.For oxygen evolution reaction（OER）,when the current density is 10 m A cm^-2,the potential is 1.56 V,and the overpotential is only 330 m V.At the same time,CoTPP/C₆₀-800 as cathode material of liquid zinc air cell showed an excellent peak power density of 111.7 m W cm^-2.These results indicate that fullerene-derived carbon materials have great potential in the field of electrocatalysis.