Iron MOF-Derived Fe2O3/NPC Decorated on MIL-88A Converted Fe3C Implanted Electrospun Porous Carbon Nanofibers for Symmetric Supercapacitors

Moderated thermal transformation of metal-organicframeworks(MOFs) empowers the synthesis of nanomaterials with precisely controlledporosities and morphologies, leading to enhanced performance in energystorage applications. Herein, we prepared MIL-88A-derived Fe3C-integrated EPCNFs (EPCNFs = electrospun porous carbon nanofibers)mats for the outside growth of Fe-MOFs using a moderated temperaturecalcination technique. The applied technique endorsed the conversionof the Fe-MOFs into Fe2O3/NPC (NPC = nanoporouscarbon) without any destruction in the morphology of the nanorods.The integrated MIL-88A-derived Fe3C reduces the intrinsicresistance and synergizes with the overall performance of the resultingnegative electrode (Fe2O3/NPC@Fe3C/EPCNFs). The resulting MOF-derived electrode materials have excellentperformance within the -1 to 0 window potential range. Theoptimized electrode Fe2O3/NPC-350@Fe3C/EPCNFs exhibits a high specific capacitance (531 F g(-1) at 1 A g(-1)) and stable cycling performance, retainingmore than 90% even after 20000 cycles. The uniform, vertical, porous,and highly interconnected tetragonal rod-like nanomaterials can alsomaintain structural integrity during continuous charge/discharge.In addition, the assembled symmetric supercapacitor (Fe2O3/ NPC-350@Fe3C/ EPCNFs//Fe2O3/ NPC-350@Fe3C/EPCNFs) exhibitsan energy density of 21.6 W h kg(-1) at a power densityof 499.05 W kg(-1) with superior cycling stability(20000 cycles at 20 A g(-1)), indicating the feasibilityof the prepared electrode for practical application in energy storagesystems.