Ribbon- and Boardlike Nanostructures of Nickel Hydroxide:  Synthesis, Characterization, and Electrochemical Properties

Abstract

We report the synthesis, characterization, and electrochemistry properties of ribbon- and boardlike nanostructures of nickel hydroxide, which crystallize in different phases. The ribbonlike nanostructures (nanoribbons) of nickel hydroxide were synthesized by treating amorphous alpha-Ni(OH)2 with high concentrations of nickel sulfate. These nanoribbons crystallized in a new phase had typical widths of 5-25 nm, thicknesses of 3-9 nm, and lengths of up to a few micrometers. After further treatment in alkali at 60 degrees C, the nanoribbons converted to boardlike nanostructures (nanoboards), which crystallized in the beta-phase with the average length-width-thickness ratio of 20:6:1. The crystal structures, Raman spectra, and electrochemical properties of these nanostructures of nickel hydroxide are described in this paper. For comparison, the amorphous alpha-Ni(OH)2 has also been investigated. Moreover, the intermediate product between the nanoribbons and the nanoboards displays a unique structure, which implied an interesting transformation process. The nanoribbons with the new phase show some unique features in Raman spectra, two new peaks located at 3534 and 3592 cm(-1) in the OH stretching region, indicating the new chemical environment of the hydroxyl groups. The nanoboards exhibit the highest specific capacity, which is close to the theoretical capacity of beta-Ni(OH)2. It suggests that the boardlike nanostructure is helpful in improving the electrochemical performance of nickel hydroxide. Because of their unique structures and properties, the nanoribbons and nanoboards of nickel hydroxide may give a new perspective for applications in the areas of catalysts and rechargeable batteries.

Controllable Synthesis of Nickel Hydroxide and Porous Nickel Oxide Nanostructures with Different Morphologies

“…[29] Lius group prepared Ni(OH) 2 nanoribbons by hydrothermal treatment of amorphous a-Ni(OH) 2 powder in the presence of high concentrations of nickel sulfate. [26,27] Using an ethanol/water/ ammonia liquor system, Tang et al fabricated Ni(OH) 2 nanobelts, subsequent annealing of which furnished porous NiO nanobelts. [28] However, in spite of the successes menAbstract: a-Ni(OH) 2 nanobelts, nanowires, short nanowires, and b-Ni(OH) 2 nanoplates have been successfully prepared in high yields and purities by a convenient hydrothermal method under mild conditions from very simple systems composed only of NaOH, NiSO 4 , and water.…”

Effect of synthesis temperature on the phase structure and electrochemical performance of nickel hydroxide

“…The XRD patterns of the samples synthesized at high temperatures (40°C and 60°C) are very similar. The characteristic diffraction peaks at 18.8°, 33.2°, 38.5°, 52.0°, 59.2°, and 62.7°in 2θ show that both samples have a crystal structure of β-nickel hydroxide (JCPDS-14-0117)[12,13]. In addition, the XRD patterns of the β-nickel hydroxides are not uniformly broadened.…”

Ni(OH)2and NiO Nanostructures: Synthesis, Characterization and Electrochemical Performance

“…All of the reflection peaks in the XRD patterns match well with the standard pattern of cubic NiO (JCPDS card No: 47-1049). 40 No peaks due to β-Ni(OH) 2 are observed, suggesting that β-Ni (OH) 2 is completely converted to NiO after being heated for 2 h. Figure 6 show the SEM images of the NiO samples BO and CO, which was obtained from samples B and C. As shown in Figure 6 the influence of different conditions on morphology and size of NiO nanostructures is not very intense.…”