Preparation And Electrochemical Performance Of Nitrogen Self-doped Porous Carbon Based On MOFs

As the world explores new options for clean and safe energy,the contribution of supercapacitors is becoming more and more obvious.Supercapacitors have the advantages of fast charging,strong cycle stability and wide operating temperature range,but the commercialization of supercapacitors is currently limited by several challenges.Many reports on supercapacitors indicate that their future development direction depends on the development of new carbon materials,which should have excellent porous structure,high specific surface area,high conductivity,and high electrochemical stability.Therefore,it is an important research topic to select a suitable carbon precursor to prepare new carbon materials and improve the electrochemical performance of supercapacitors.Studies have shown that the advantages of porous carbon derived from MOFs as precursors are controllable porous structure and high specific surface area.Moreover,MOFs only need to produce ideal porous carbon through the direct carbonization process.In addition,MOFs can also be derived from heteroatoms doped with porous carbon.The presence of heteroatoms can improve the interface wettability of porous carbon materials,which is conducive to the supply of electrolyte ions In turn,the electrochemical performance of porous carbon is improved.This article focuses on improving the electrochemical performance of supercapacitors,and is committed to using MOFs as a carbon precursor to prepare high-performance nitrogen self-doped porous carbon through a one-step carbonization method,and explores its microscopic morphology and structure,and systematically tests its electrochemical performance;The main research of this paper is as follows:?1?The metal-organic framework[Zn(C₁₀H₁₄O₄)?C₄H₆N₂?]_n,abbreviated as ZDM,is prepared by the solvent method.Using ZDM as a precursor,one-step carbonization method was used to prepare nitrogen self-doped porous carbon ZDMC-T-t.The effects of carbonization temperature and time on the microstructure and electrochemical performance of nitrogen self-doped porous carbon ZDMC-Tt were investigated;The results showed that the specific surface area of nitrogen self-doped porous carbon ZDMC-800-2 reached 648.18m²g^-1,nitrogen The oxygen content is as high as 16.35%and 6.51%respectively;the specific capacitance of nitrogen self-doped porous carbon ZDMC-800-2 at 1.0 A g^-1 is as high as 219.4 F g^-1,and after 5000 times of constant current charge and discharge,the capacitance retention rate is still 88.94%;when the current density increases from 1.0 A g^-1to 10.0 A g^-1,the decay rate is only 14.18%;indicating that the nitrogen self-doped porous carbon ZDMC-800-2 has excellent electrochemical performance and excellent rate performance.?2?The solvent method is used to prepare the metal organic framework{[Zn?1,4-BDC?_0.5?3-NH₂-trz?]·?solvent?]}_n,abbreviated as ZAP.Using ZAP as a precursor,one-step carbonization method was used to prepare nitrogen self-doped porous carbon ZAPC-T.Investigate the effect of carbonization temperature on the microstructure and electrochemical performance of nitrogen self-doped porous carbon ZAPC-T;the results show that the specific surface area of nitrogen self-doped porous carbon ZAPC-800 is up to728.57 m²g^-1,and the nitrogen and oxygen contents up to 19.09%,5.93%;the specific capacitance of nitrogen self-doped porous carbon ZAPC-800 is up to 225.4 F g^-1 at 1.0 A g^-1,and after 5000 constant current charge and discharge,the capacitance retention rate is still83.01%;When 1.0 A g^-1 is increased to 10.0 A g^-1,the attenuation rate is 21.2%.It shows that the nitrogen self-doped porous carbon ZAPC-800 has excellent electrochemical performance and good cycle stability.?3?The metal organic framework{[?CH₃?₂NH₂]₂[Zn₅?TDA?₄?TZ?₄]·4DMF}_n,abbreviated as ZHT,is prepared by the solvent method.Using ZHT as a precursor,one-step carbonization method was used to prepare nitrogen self-doped porous carbon ZHTC-T.Investigate the microstructure and electrochemical performance of carbonization temperature on nitrogen self-doped porous carbon ZHTC-T;the research results show that the specific surface area of nitrogen self-doped porous carbon ZHTC-750 reaches 494.43m²g^-1,and the nitrogen and oxygen contents are up to 7.51%,4.88%;the specific capacitance of nitrogen self-doped porous carbon ZHTC-750 is up to 230.2 F g^-1 at 1.0 A g^-1,and after 5000 constant current charging and discharging,the capacitance retention rate is still 93.05%;the current density is from 1.0 When A g^-1 is increased to 10.0 A g^-1,the attenuation rate is only 11.9%.It shows that the nitrogen self-doped porous carbon ZHTC-750 has excellent electrochemical performance and good cycle stability.