Self-assembly Preparation And Electrochemical Performance Of Porphyrin Polymer

Porphyrins are macrocyclic compounds with good optical and electrical properties,which can form different supramolecular structures through self-assembly.Therefore,porphyrins have been widely applied in catalysis,photoelectric conversion,sensing,adsorption,etc.In recent years,researchers have discovered that porphyrin-based materials with highly conjugated?orbitals are suitable for charge transfer reaction,thus exhibiting excellent performance in Li-ion batteries and supercapacitors.So far,the related research about porphyrin polymers is limited to the investigation of polymerization mechanism and method.However,these researches have not involved the morphology modulation of porphyrin polymers and the influence of morphology on related properties.In addition,the current synthesis conditions of porphyrin polymer are harsh and cumbersome,which extremely limits the morphology regulation of porphyrin polymers.Hence,in combination with the characteristics of porphyrin molecules,it is not only important but also meaningful to develop a simple and gentle method to realize the controllable preparation of porphyrin polymers.Here we have successfully achieved the controllable adjustment of porphyrin polymer and obtained several porphyrin polymers with different morphologies through self-assembly,and they have been applied as an electrode to explore the performance of lithium ion storage.1.Pre-polymerization enables controllable synthesis of nanosheet-based porphyrin polymers.We successfully achieved the morphology adjustment of porphyrin polymer through ion-induced pre-polymerization and self-assembly strategy.Fe³⁺was employed as pre-polymerization catalyst and self-assembly regulator of meso-5,10,15,20-tetra?4-aminophenyl?porphyrin?TAPP?.Simply changing the concentration of Fe³⁺,we can obtain two morphological porphyrin polymers including PTAPP-Nanocubes?PTAPP-NC?and PTAPP-Nanosheets?PTAPP-NS?,both of which are stacked by nanosheets.The prepared PTAPP-NC material possessed a high intrinsic bulk conductivity of 1.49×10^-4S m^-1,and exhibited excellent electrochemical performance in Li-ion batteries.PTAPP-NC electrode delivered high specific capacity of⁶50 mA h g^-1 at the current density of100 mA g^-1.Moreover,a reversible capacity of 180 mA h g^-1 can be retained after 2000cycles at a high current density of 2 A g^-1,which demonstrated its outstanding long-cycle stability.2.Preparation of mesoporous porphyrin polymer directed by block copolymer micelles.Due to the hydrogen bonds between PS-b-PAA and meso-5,10,15,20-tetra?4-aminophenyl?porphyrin,PS-b-PAA micelles have been used to guide the assembly of porphyrin molecules.Through adjusting the concentration of micelles,the precursor and the solvent,we successfully prepared mesoporous porphyrin polymer?mPTAPP?.Due to its porous structure which is of benefit for the insertion/extraction of lithium ions and the sufficient contact with electrolyte,combined the nature of easy charge-transfer,we used the as-made material in Li-ion batteries.As an anode,mPTAPP exhibited excellent rate performance and high Coulomb efficiency which is more than 98%.Furthermore,more active sites may be exposed during the cycles according to the result,which further improved the lithium ions storage performance of mPTAPP electrode.