Fabrication of a snail shell-like structured MnO₂@CoNiO₂ composite electrode for high performance supercapacitors

Abstract

MnO2@CoNiO2 snail shell-like structures exhibits superior specific capacitance and cyclic stability than the MnO2 and CoNiO2 electrodes.

Metal–Organic Framework Templated 3D Hierarchical ZnCo2O4@Ni(OH)2 Core–Shell Nanosheet Arrays for High‐Performance Supercapacitors

“…Figure a shows the cyclic voltammetry (CV) curves of the ZnCo 2 O 4 /NF, Ni(OH) 2 /NF and ZnCo 2 O 4 @Ni(OH) 2 /NF at the same scan rate of 30 mV s −1 . Evidently, all the CV curves show clear redox peaks different from the electric double‐layer capacitors (EDLCs), indicating that these electrodes exhibit mainly pseudocapacitive behavior based on electron transfer across the electrode–electrolyte interface . The redox peaks mainly arose from the reversible faradaic redox reactions related to M−O/M− O −OH (M=Co or Ni) .…”

“…Figure 4a shows the cyclic voltammetry (CV) curves of the ZnCo 2 O 4 /NF,N i(OH) 2 /NF and ZnCo 2 O 4 @Ni(OH) 2 /NF at the same scan rate of 30 mV s À1 .E vidently,a ll the CV curves show clear redox peaks different from the electric double-layer capacitors (EDLCs), indicating thatt hese electrodes exhibit mainly pseudocapacitive behavior based on electron transfer across the electrode-electrolyte interface. [21] The redoxp eaks mainly arose from the reversible faradaic redox reactions related to MÀO/MÀOÀOH (M = Co or Ni). [22] Moreover,t he integral area of CV curve of the ZnCo 2 O 4 @Ni(OH) 2 /NF electrode was larger than that of the ZnCo 2 O 4 /NF or Ni(OH) 2 /NF electrodes, implyingt hat the ZnCo 2 O 4 @Ni(OH) 2 /NF has the largest capacity.T he CV curves of ZnCo 2 O 4 @Ni(OH) 2 /NF electrode at different scan rates are presented in Figure 4b.W ith the scan rate increasedf rom 5t o5 0mVs À1 ,t he shape of CV curvesh ad no clear changes, indicating the good rate capability and electrochemicalr eversibility of the electrode.…”

Urchin-like FeOOH hollow microspheres decorated with MnO2 for enhanced supercapacitor performance

“…One promising approach to improve their performance is to combine other metal oxides in a composite. Manganese dioxide (MnO 2 ) with favorable properties and high theoretical specific capacitance (1370 F g −1 ) makes it a promising electrode material in energy storage and conversion devices [26][27][28][29][30]. Furthermore, three-dimensional (3D) transitional metal oxides/ hydroxides nanostructures assembled from low-dimensional building blocks [31][32][33][34] exhibit enhanced properties compared to their bulk counterparts by offering a large specific surface area, high surface/body ratios, the enhanced permeability for the electrolyte ions, and rich electrochemically active sites [35].…”

A New Nanocomposite from Vesuvian Slope Pinecones for Azo-Dyes Removal

“…In particular, the amount of MR in the solution decreases with an increase in the adsorbent dosage, because of the increasing availability of binding sites. However, the adsorption capacity does not increase as the adsorbent amount increases, probably due to the increased competition for the active adsorption sites and dye molecules . Indeed, the adsorption capacity decrease (mg/g) with an adsorbent dosage increase is due to the increased number of unsaturated sites .…”

“…However, the adsorption capacity does not increase as the adsorbent amount increases, probably due to the increased competition for the active adsorption sites and dye molecules. 44 Indeed, the adsorption capacity decrease (mg/g) with an adsorbent dosage increase is due to the increased number of unsaturated sites. 45 The maximum MR removal was exhibited at 1.4 g/L with a removal percentage of >98% and a q t value of 76.03 mg/g.…”