Electrochemical measurements of synthesized nanostructured β-Ni(OH)2 using hydrothermal process and activated carbon based nanoelectroactive materials

Abstract

In this investigation, nickel hydroxide Ni(OH) 2 based nanostructured materials were synthesized by simple and low cost free template hydrothermal method at two different growth temperatures with and without SDS surfactant. The X-ray diffraction, Raman spectroscopy and field emission scanning electron microscopy analysis confirmed the formation of β-Ni(OH) 2 pure brucite crystalline phase in spherical nanoparticle morphology with an average diameter ranging from 8 to 27 nm. In the second step, these nanospherical agglomerated hydroxide particles with activated carbon addition were performed as electroactive materials deposited on nickel foam current collector as working electrodes. The electrochemical tests in a three-electrode configuration using 6 MKOH electrolyte show that the best electroactive NPs (β bc-Ni(OH) 2 and β-Ni(OH) 2 obtained at optimized conditions, have a maximum specific capacitance (C s) of 4697 F g −1 and 3431 F g −1 at 5 mV s −1 scan rate with a specific capacity (Q s) of 744 mAh g −1 and 618 mAh g −1 at 1 A g −1 current density with an R s of about 0.24 and 0.28 Ω, respectively. At 30 A g −1 after 1700 cycles, the coulombic retention is around 99.06% (or capacity retention 109 mAh g −1), demonstrating remarkable cycling stability for Ni based hydroxide.

Separation and Characterization of Nickel Hydroxide from Waste Solution Using Ca(OH)2 Precipitation in Chloride Media

“…The observed trend in this study aligns with the findings in Ref. [19]. The aforementioned study demonstrated that the optimal conditions for investigating the precipitation process of other metal ions, such as Fe, in a mixture with nickel (Ni) is achieved at higher temperatures.…”

Reactive sputter deposition of β-Ni(OH)2 thin films in Ar + H2O mixed gas atmosphere at a substrate temperature of −80 °C

“…35,36) The blue rectangle indicates the region where Ni(OH) 2 powders and nanostructures were synthesized by wet chemical methods. [38][39][40] The pressure at the boundary of water and water vapor 41,42) (green dashed line) at the synthesis temperature was used for the plot since the Ni(OH) 2 samples were synthesized in liquid water. These experimental results agree with the results expressed by Eq.…”

“…This result strongly suggests that substrate cooling is necessary to form Ni(OH 35,36) and the blue rectangle indicates the region where Ni(OH) 2 thin films and nanostructures were synthesized by wet chemical methods. [38][39][40] Green dashed lines show the boundary between ice, water, and water vapor. 41,42) Points A, B, and C indicate the deposition conditions used in this study.…”

“…Blue and red lines are the equilibrium pressures of H 2 O when Ni(OH) 2 decomposes to NiO and H 2 O, and the equilibrium pressure of O 2 when NiO decomposes to Ni and O 2 , respectively. The red rectangle indicates the region where Ni(OH) 2 powders were thermally decomposed to NiO,35,36) and the blue rectangle indicates the region where Ni(OH) 2 thin films and nanostructures were synthesized by wet chemical methods [38][39][40]. Green dashed lines show the boundary between ice, water, and water vapor 41,42).…”

One-step synthesis of Ni(OH)2/MWCNT nanocomposites for constructing a nonenzymatic hydroquinone/O2fuel cell

“…The b-Ni(OH) 2 possesses a hexagonal arrangement of brucite-type layers ordered along the axis C, correspondingly, the other structure is randomly stacked along the C axis. 13 It has been reported that there were many successful methods for the synthesis of Ni(OH) 2 , including solvent heat, 14 ultrasonic, 15 hydrothermal, 16 co-precipitation 17 and so on. In recent years, multi-walled carbon nanotubes (MWCNTs) are very popular and widely used in biosensors, 17 supercapacitors, 18 biofuel cells 19 and other elds because of their small size, large specic surface area, high conductivity and chemical stability.…”