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Nanoengineering of NiO/MnO 2 /GO Ternary Composite for Use in High-Energy Storage Asymmetric Supercapacitor and Oxygen Evolution Reaction (OER).

Natasha ArshadMuhammad UsmanMuhammad AdnanMuhammad Tayyab AhsanMah Rukh RehmanSofia JavedZeeshan AliMuhammad Aftab AkramGeorge P DemopoulosAsif Mahmood
Published in: Nanomaterials (Basel, Switzerland) (2022)
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/MnO 2 /rGO (NMGO) having a range of active sites for enhanced electrochemical activity. The resultant sandwich structure consisted of a mesoporous backbone with NiO and MnO 2 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.
Keyphrases
  • reduced graphene oxide
  • gold nanoparticles
  • carbon nanotubes
  • metal organic framework
  • solid state
  • ionic liquid
  • drug delivery
  • transition metal
  • climate change
  • cancer therapy
  • tissue engineering