Galvanic displacement assembly of ultrathin Co₃O₄nanosheet arrays on nickel foam for a high-performance supercapacitor

Abstract

High-performance supercapacitors are very desirable for many portable electronic devices, electric vehicles and high-power electronic devices. Herein, a facile and binder-free synthesis method, galvanic displacement of the precursor followed by heat treatment, is used to fabricate ultrathin CoO nanosheet arrays on nickel foam substrate. When used as a supercapacitor electrode the prepared CoO on nickel foam exhibits a maximum specific capacitance of 1095 F g at a current density of 1 A g and good cycling stability of 71% retention after 2000 cycling tests. This excellent electrochemical performance can be ascribed to the high specific surface area of each CoO nanosheet that comprises numerous nanoparticles.

Efficient Co@Co3O4 core-shell catalysts for photocatalytic water oxidation and its behaviors in two different photocatalytic systems

“…Combined with the results showed in Fig. 8(c), the peak of O 1s becomes wider and higher after the reaction, it is a typical embodiment of the increase of CoO [61][62][63], which is consistent with the analysis results of Fig. 8(a).…”

One-Step In Situ Self-Assembly of Cypress Leaf-Like Cu(OH)2 Nanostructure/Graphene Nanosheets Composite with Excellent Cycling Stability for Supercapacitors

“…With increasing scan rate, CV curves maintain a similar profile and the current response increased, indicating the good rate capability and good reversibility of Faradic reactions [17, 27]. Meanwhile, the oxidation and reduction peak respectively shift to more positive and more negative potentials, due to the limited ion diffusion time or high-electron hopping resistance [34].…”

NiO/NixCo3−xO4 porous ultrathin nanosheet/nanowire composite structures as high-performance supercapacitor electrodes

“…This composite nanostructure can enlarge the contact surface area with electrolyte and facilitate the penetration of the ions, promoting the velocity of redox reaction. 37 The high-magnification TEM images shown as Fig. 3c and d reveal that the diameter of nanowires is about 50–80 nm and the mesopores are also present both in the ultrathin nanosheets and nanowires with a size of 5 to 8 nm.…”