Low-crystalline nickel hydroxide nanosheets embedded with NiMoO₄ nanoparticles on nickel foam for high-performance supercapacitor applications

Abstract

Transition metal hybrid nanomaterials have attracted wide attention in the field of energy storage due to their rich redox activity and good conductivity and structural stability. In this work, low-crystalline...

Deep Reconstruction of Mo‐based OER Pre‐Catalysts in Water Electrolysis at High Current Densities

“…The lattice fringes observed in the high-resolution TEM (HR-TEM) images of the post-OER electrodes correspond to the characteristic d-spacing of NiOOH, NiO 2 , and NiO confirming the Mo dissolution-assisted formation of a highly crystalline Ni oxide-based structure without any distinct boundaries or heterojunctions indicating the conversion of Ni-oxide or hydroxide structures to Modeficient NiOOH structures. [45] The formation of a layered structure and the presence of NiO 2 suggest that NiOOH is fully dehydrogenated, confirming the formation of the γ-NiOOH phase and NiO 2 layers providing more surface-active sites. The localized formation of NiO 2 is possibly due to local temperature effects during high current-density operations under oxidizing conditions.…”

Controllable sulfidation of polymetallic nickel cobalt molybdenum layered double hydroxides on Ni foam for high-performance hybrid supercapacitors

“…Based on the above microstructural characterization, it is inferred that Na 2 MoO 4 ·2H 2 O and Ni(NO 3 ) 2 ·6H 2 O/Co(NO 3 ) 2 ·6H 2 O in solution react to form NiMo 4 /CoMoO 4 , while the OH − from the decomposition of urea at 110 °C combines with Ni 2+ and Co 2+ to form Ni 2 (CO 3 )(OH) 2 and Co(CO 3 ) 0.5 (OH)·0.11H 2 O, respectively. 24,39 During the secondary hydrothermal reaction, S 2− combines with other metal cations to form MS, where M represents the Ni, Co and Mo elements.…”

“…In addition, the two peaks located at 863.18 eV and 881.00 eV are satellite peaks. [22][23][24] The atomic ratio of Ni 3+ /Ni 2+ increased from 0.34 in NCM-LDH to 0.41 in NCMS-2. The higher Ni 3+ /Ni 2+ ratio suggests that more Ni 3+ sites may be present on the NCMS-2 surface.…”

Design of Ni(OH)2 Nanosheets@NiMoO4 Nanofibers’ Hierarchical Structure for Asymmetric Supercapacitors

“…A calculation based on the equation ( I = aυ b ) [50] shows that there is a relationship between the peak current (i) and the scan rate (υ). The slopes (value of b) of the NMH−2 and AC electrodes (anode and cathode) are 0.81 and 0.75, respectively, indicating that the charge−storage mechanism of NMH−2 coexists with the processes of diffusion−control and capacitance [51,52]. Therefore, the above two contributions were studied separately.…”