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

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 CoO (oz-CoO-PNCNF) are obtained by calcining the electrospun polymer. The surface area of oz-CoO-PNCNF is exceptionally high, 429 m g, with the pore size predominantly ≈2 - 5 nm. Thin conducting polymer films of poly-(3,4-ethylenedioxythiophene) are formed onto oz-CoO-PNCNF (oz-CoO-PNCNF/PEDOT). A porous, long nanofibrous structure (≈100 nm thick) of oz-CoO-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) of 417 F g (oz-CoO-PNCNF/PEDOT). Free-standing supercapacitor device delivers excellent performance in asymmetric assembly (oz-CoO-PNCNF/PEDOT//PNCNF) with 141.1 Wh kg and 84% C at the end of 5000 charge-discharge cycles. The excellent porous network, combined with finely-tuned nano-sized CoO particles and an overlying thin electropolymer film, work together to establish high energy, efficient, and stable supercapacitors.