PolyHIPE Derived Freestanding 3D Carbon Foam for Cobalt Hydroxide Nanorods Based High Performance Supercapacitor

The current paper describes enhanced electrochemical capacitive performance of chemically grown Cobalt hydroxide (Co(OH)₂) nanorods (NRs) decorated porous three dimensional graphitic carbon foam (Co(OH)₂/3D GCF) as a supercapacitor electrode. Freestanding 3D porous GCF is prepared by carbonizing, high internal phase emulsion (HIPE) polymerized styrene and divinylbenzene. The PolyHIPE was sulfonated and carbonized at temperature up to 850 °C to obtain graphitic 3D carbon foam with high surface area (389 m² g^-1) having open voids (14 μm) interconnected by windows (4 μm) in monolithic form. Moreover, entangled Co(OH)₂ NRs are anchored on 3D GCF electrodes by using a facile chemical bath deposition (CBD) method. The wide porous structure with high specific surface area (520 m² g^-1) access offered by the interconnected 3D GCF along with Co(OH)₂ NRs morphology, displays ultrahigh specific capacitance, specific energy and power. The Co(OH)₂/3D GCF electrode exhibits maximum specific capacitance about ~1235 F g^-1 at ~1 A g^-1 charge-discharge current density, in 1 M aqueous KOH solution. These results endorse potential applicability of Co(OH)₂/3D GCF electrode in supercapacitors and signifies that, the porous GCF is a proficient 3D freestanding framework for loading pseudocapacitive nanostructured materials.