3D Graphene Frameworks/Co₃O₄ Composites Electrode for High‐Performance Supercapacitor and Enzymeless Glucose Detection

Abstract

3D graphene frameworks/Co O composites are produced by the thermal explosion method, in which the generation of Co O nanoparticles, reduction of graphene oxide, and creation of 3D frameworks are simultaneously completed. The process prevents the agglomeration of Co O particles effectively, resulting in monodispersed Co O nanoparticles scattered on the 3D graphene frameworks evenly. The prepared 3D graphene frameworks/Co O composites used as electrodes for supercapacitor display a definite improvement on electrochemical performance with high specific capacitance (≈1765 F g at a current density of 1 A g ), good rate performance (≈1266 F g at a current density of 20 A g ), and excellent stability (≈93% maintenance of specific capacitance at a constant current density of 10 A g after 5000 cycles). In addition, the composites are also employed as nonenzymatic sensors for the electrochemical detection of glucose, which exhibit high sensitivity (122.16 µA mM cm ) and noteworthy lower detection limit (157 × 10 M, S/N = 3). Therefore, the authors expect that the 3D graphene frameworks/Co O composites described here would possess potential applications as the electrode materials in supercapacitors and nonenzymatic detection of glucose.

Vertically Aligned Graphene Nanosheet Arrays: Synthesis, Properties and Applications in Electrochemical Energy Conversion and Storage

“…[73,98] As a reference, the electrodes were first tested in liquid electrolyte, and a high specific capacity of 3480 F g −1 was obtained with a small Co 3 O 4 loading of ≈25 µg, which was close to its theoretical value of 3560 F g −1 . The specific capacity reported was much higher than that of GFs-Co 3 O 4 NPs, [99,100] and GFs-Co 3 O 4 nanowire composites, [101] revealing the superiority of the VAGNA structure as a scaffold in pseudocapacitor electrodes. ), much better than the symmetric capacitors based on graphene/metal-oxides previously reported (Figure 7d,e).…”

A Flexible Stretchable Hydrogel Electrolyte for Healable All‐in‐One Configured Supercapacitors

“…The rapid progress of flexible healable electronics potentially accelerates the evolution of the corresponding wearable energy storage modules with reliable flexibility, sufficient coupling ability, robust self‐healing capability, and autonomously healable electrochemical performances without additional stimuli, such as magnetic field, external additives, heat, solvents, and light . Among the various wearable flexible energy storage devices, supercapacitor is well developed with the facilitation of high specific capacitance, excellent power density, fast charge/discharge ability, and superior electrochemical cycling stability . Until now, diverse self‐healing supercapacitors have been well established through the dynamic supramolecular interaction .…”

Core–Shell Nitrogen‐Doped Carbon Hollow Spheres/Co3O4 Nanosheets as Advanced Electrode for High‐Performance Supercapacitor

“…Transition metal oxides have been considered as potential candidate materials for pseudocapacitors owing to their high theoretical specific capacitances and easy availabilities . Among them, cobalt oxide, with a high theoretical capacitance of 3560 F g −1 , has been intensively developed . In recent years, various structures of cobalt oxide including nanoparticle, nanofiber, microsphere, nanobox/nanocage, hollow spheres, and nanoneedle, have been synthesized to enhance their electrochemical performance.…”