Fabrication of hierarchical NiCo2S4 nanotubes@NiMn-LDH nanosheets core-shell hybrid arrays on Ni foam for high-performance asymmetric supercapacitors

Coupling NiMn-Layered Double Hydroxide Nanosheets with NiCo2S4 Arrays as a Heterostructure Catalyst to Accelerate the Urea Oxidation Reaction

“…As displayed in Figure b, the XPS spectrum of Ni 2p was deconvoluted into two spin–orbit doublets and two shakeup satellites. The peaks located at binding energies of 855.3 and 873.1 eV assigned to Ni 2+ derived from Ni 2p 3/2 and Ni 2p 1/2 , while the peaks at binding energies of 861.1 and 897.1 eV were indexed to the shakeup satellites. , Figure c presents the Mn 2p spectrum, which had two characteristic peaks, one at a binding energy of 643.1 eV associated with Mn 2p 3/2 and the other at a binding energy of 654.6 eV assigned to Mn 2p 1/2 , thus confirming the presence of Mn 3+ . , In the Co 2p spectrum, two spin–orbit doublets and two shakeup satellites were detected (Figure d). The peaks with binding energies of 775.6 and 796.1 eV were associated with Co 3+ , whereas the peaks located at 781.4 and 797.7 eV originated from the spin–orbit doublet of Co 2+ , along with the two shakeup satellites at 787.5 and 801.6 eV, respectively. , In the S 2p spectrum (Figure e), the peaks with binding energies of 161.7 and 163.5 eV were indexed to S 2p 3/2 and S 2p 1/2 , respectively, from the S 2– in NiCo 2 S 4 . , The characteristic peak located at 168.5 eV was attributed to SO 4 2– . , The XPS spectrum for O 1s in Figure f was characterized by peaks with binding energies of 530.2 and 531.8 eV, which were assigned to O–H bonds and surface-adsorbed oxygen in the NiCo 2 S 4 @NiMn LDH heterostructure, respectively …”

“…40,46 Figure 3c presents the Mn 2p spectrum, which had two characteristic peaks, one at a binding energy of 643.1 eV associated with Mn 2p 3/2 and the other at a binding energy of 654.6 eV assigned to Mn 2p 1/2 , thus confirming the presence of Mn 3+ . 47,48 In the Co 2p spectrum, two spin−orbit doublets and two shakeup satellites were detected (Figure 3d). The peaks with binding energies of 775.6 and 796.1 eV were associated with Co 3+ , whereas the peaks located at 781.4 and 797.7 eV originated from the spin−orbit doublet of Co 2+ , along with the two shakeup satellites at 787.5 and 801.6 eV, respectively.…”

3D hierarchical core–shell structural NiCoMoS@NiCoAl hydrotalcite for high-performance supercapacitors

“…[4][5][6][7][8][9][10][11] Among them, transition metal hydroxides, especially 2D layered double hydroxides (LDHs) with a hydrotalcite-like structure, have been widely investigated due to the low cost, multiple oxidation states and high theoretical specic charge. 12, 13 Ni/Cobased LDHs, such as Al-CoNiLDH, 14 CoAl-LDH, 15,16 CoNi-LDH, 17 NiMn-LDH, 18 NiCo-LDH, 19 NiCoAl-LDH, 20 Ag-laminated NiC-oMo-LDH 21 and so forth, have been prepared by various methods to improve the electrochemical performances. Despite the high theoretical specic charge, Ni/Co-based LDHs are unable to satisfy the practical requirements due to the intrinsically poor electrical conductivity and easy aggregation.…”

Flexible Solid-State Asymmetric Supercapacitor with High Energy Density and Ultralong Lifetime Based on Hierarchical 3D Electrode Design

“…Furthermore, electrochemical impedance spectroscopy (EIS) and cycling performance were also investigated to evaluate the stability and conductivity of the electrodes. As demonstrated in Figure 4e, the capacitance retention of NF@ NiMoO 4 @NiCo 2 O 4 increases obviously in the first 1000 cycles, owing to the gradual activation of the electrode, 42,43 and can still maintain 91.6% of the capacitance and 99.4% of the Coulomb efficiency after 10 000 cycles, demonstrating its superior cycling stability and excellent electrochemical reversibility. Furthermore, the morphology analysis of the used NF@NiMoO 4 @NiCo 2 O 4 after 10 000 cycles shows no substantial structural variation (Figure S4), and the hierarchical structure is well kept.…”