Nanoengineering of NiO/MnO2/GO Ternary Composite for Use in High-Energy Storage Asymmetric Supercapacitor and Oxygen Evolution Reaction (OER)

Abstract

Designing multifunctional nanomaterials for high performing electrochemical energy conversion and storage devices has been very challenging. A number of strategies have been reported to introduce multifunctionality in electrode/catalyst materials including alloying, doping, nanostructuring, compositing, etc. Here, we report the fabrication of a reduced graphene oxide (rGO)-based ternary composite NiO/MnO2/rGO (NMGO) having a range of active sites for enhanced electrochemical activity. The resultant sandwich structure consisted of a mesoporous backbone with NiO and MnO2 nanoparticles encapsulated between successive rGO layers, having different active sites in the form of Ni-, Mn-, and C-based species. The modified structure exhibited high conductivity owing to the presence of rGO, excellent charge storage capacity of 402 F·g−1 at a current density of 1 A·g−1, and stability with a capacitance retention of ~93% after 14,000 cycles. Moreover, the NMGO//MWCNT asymmetric device, assembled with NMGO and multi-wall carbon nanotubes (MWCNTs) as positive and negative electrodes, respectively, exhibited good energy density (28 Wh·kg−1), excellent power density (750 W·kg−1), and capacitance retention (88%) after 6000 cycles. To evaluate the multifunctionality of the modified nanostructure, the NMGO was also tested for its oxygen evolution reaction (OER) activity. The NMGO delivered a current density of 10 mA·cm−2 at the potential of 1.59 V versus RHE. These results clearly demonstrate high activity of the modified electrode with strong future potential.

Recent Progress Using Graphene Oxide and Its Composites for Supercapacitor Applications: A Review

“…A composite material consisting of NiO, MnO 2 , and GO (NiO/MnO 2 /GO) was recently created by ultrasonication for the supercapacitor application [83]. To this degree, Tour's approach was first used to produce GO for the composite preparation.…”

Investigation of Highly Active Carbon‐, Cobalt‐, and Noble Metal‐Free MnO2/NiO/Ni‐Based Bifunctional Air Electrodes for Metal–Air Batteries with an Alkaline Electrolyte

“…[ 6 ] Furthermore, its integration into a hybrid catalyst or mixing with an OER active catalyst is quite common in literature. [ 4,15–34 ]…”

“…[6] Furthermore, its integration into a hybrid catalyst or mixing with an OER active catalyst is quite common in literature. [4,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] Since the electronic conductivity of metal-oxide catalysts is low compared to metallic catalysts, they are typically mixed with conductive additives and major work on MnO 2 -based catalysts bifunctional air electrodes has been performed in carbon-based systems. [4,12,[15][16][17]22,24,25,[28][29][30][35][36][37][38][39][40][41] However, the long-term stability of carbon-based bifunctional air electrodes is not satisfactory due to the carbon corrosion potential being close to that of the OER.…”

“…[ 6 ] Furthermore, its integration into a hybrid catalyst or mixing with an OER active catalyst is quite common in literature. [ 4 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]…”

The Self-Supporting NiMn-LDHs/rGO/NF Composite Electrode Showing Much Enhanced Electrocatalytic Performance for Oxygen Evolution Reaction

“…Since the anodic four-electron reaction process of OER is much slower than that of the two-electron reaction process of HER, high overpotential and the sluggish kinetics inevitably occur in the electrolysis of water. Therefore, the development of an effective electrocatalyst to improve the energy conversion efficiency is needed [2,3]. However, the slow kinetics of the OER presents a significant challenge for the widespread implementation of water electrolysis as a large-scale hydrogen production technology.…”