Development of Oleylamine‐Directed Nano‐OZIF‐67 Induced Microporous Carbon Nanofiber Conjugated with Tiny Fibrous PEDOT Polymer for Hybrid‐Capacitor Electrodes

Abstract Making nanostructured metal oxides intertwined with graphitic carbon materials is critically important to construct hybrid supercapacitors with high‐performance, cost‐affordable, and free‐standing 1D hybrid electrode material and is of foremost importance to responding positively to the impending energy crisis. Fine‐tuned nano‐sized ZIF‐67 particles of 5 – 25 nm width (OZIF‐67) are achieved using oleylamine‐involved synthesis and are seeded into fibrous poly‐PAN‐PVP. Porous N‐doped carbon nanofibers impregnated with OZIF‐67‐derived Co ₃ O ₄ ( oz ‐Co ₃ O ₄ ‐PNCNF) are obtained by calcining the electrospun polymer. The surface area of oz ‐Co ₃ O ₄ ‐PNCNF is exceptionally high, 429 m ² g ⁻¹ , with the pore size predominantly ≈2 – 5 nm. Thin conducting polymer films of poly‐(3,4‐ethylenedioxythiophene) are formed onto oz ‐Co ₃ O ₄ ‐PNCNF ( oz ‐Co ₃ O ₄ ‐PNCNF/PEDOT). A porous, long nanofibrous structure (≈100 nm thick) of oz ‐Co ₃ O ₄ ‐PNCNF and a spongy needle‐like network of PEDOT interconnecting outer layers are established from FESEM images. The material has shown excellent energy storage capability with the specific capacitance (C _S ) of 417 F g ⁻¹ ( oz ‐Co ₃ O ₄ ‐PNCNF/PEDOT). Free‐standing supercapacitor device delivers excellent performance in asymmetric assembly ( oz ‐Co ₃ O ₄ ‐PNCNF/PEDOT//PNCNF) with 141.1 Wh kg ⁻¹ and 84% C _S at the end of 5000 charge–discharge cycles. The excellent porous network, combined with finely‐tuned nano‐sized Co ₃ O ₄ particles and an overlying thin electropolymer film, work together to establish high energy, efficient, and stable supercapacitors.