Structural defects and electrochemical reactivity of β-Ni(OH)2

Bernard, Marie‐Claude; Cortés, Ramiro de Jesús Hernández; Кеддам, М.; Takenouti, H.; Bernard, Patrick; Sényarich, S.

doi:10.1016/s0378-7753(96)02482-2

Cited by 213 publications

(150 citation statements)

References 9 publications

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“…29,30 Bernard et al observed that dry samples, which initially show this peak, that are rinsed with water and reanalyzed while still wet, lose the peak completely. 30 This indicates that it is a surface-related phenomenon, although the exact origin is unclear. Bernard et al proposed that the O−H stretch for surface hydroxide groups is at higher energy than for those opposed by adjacent layers.…”

Section: Resultsmentioning

confidence: 99%

“…15 Corrosion studies of Ni have focused on the investigation of the nature of its surface layers and passivation phenomena. 16−19 Two phases of Ni(OH) 2 , denoted α and β, were first established from X-ray diffraction (XRD) patterns, 2 and their physical properties have since been thoroughly investigated utilizing infrared spectroscopy (IR), 1,4,6,7,14,20−28 Raman spectroscopy, 5,22,29−39 extended X-ray absorption fine structure (EXAFS), 30,40 inelastic neutron scattering (INS), 41 neutron diffraction, 42−44 and more detailed XRD studies. 10,31,45,46 Typically, Ni(OH) 2 is prepared by the basification of an aqueous nickel(II) salt solution either by the addition of an alkali hydroxide or ammonia or by the electrochemical reduction of water.…”

Section: Introductionmentioning

confidence: 99%

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Raman and Infrared Spectroscopy of α and β Phases of Thin Nickel Hydroxide Films Electrochemically Formed on Nickel

et al. 2012

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The present work utilizes Raman and infrared (IR) spectroscopy, supported by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) to re-examine the fine structural details of Ni(OH) 2 , which is a key material in many energy-related applications. This work also unifies the large body of literature on the topic. Samples were prepared by the galvanostatic basification of nickel salts and by aging the deposits in hot KOH solutions. A simplified model is presented consisting of two fundamental phases (α and β)o fN i ( O H ) 2 and a range of possible structural disorder arising from factors such as impurities, hydration, and crystal defects. For the first time, all of the lattice modes of β-Ni(OH) 2 have been identified and assigned using factor group analysis. Ni(OH) 2 films can be rapidly identified in pure and mixed samples using Raman or IR spectroscopy by measuring their strong O−H stretching modes, which act as fingerprints. Thus, this work establishes methods to measure the phase, or phases, and disorder at a Ni(OH) 2 sample surface and to correlate desired chemical properties to their structural origins.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Raman and Infrared Spectroscopy of α and β Phases of Thin Nickel Hydroxide Films Electrochemically Formed on Nickel

et al. 2012

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“…The band at ∼445 cm −1 is assigned to the Ni-O stretching in α-Ni(OH) 2 (in the range of 445-465 cm −1 ). 35 In addition, a mode at 519 cm −1 was also observed for NiFe LDH, which is proposed to arising from the incorporation of Fe in the Ni(OH) 2 . 36 Whereas for Ni NP/NiFe LDH, the detection of two other bands at 490 cm −1 and 530 cm −1 could be assigned to the Ni-O vibration, 37 suggesting that the Ni NP/NiFe LDH was defective or disordered.…”

Section: Fig 1 (As Well Asmentioning

confidence: 95%

Ni Nanoparticles Decorated NiFe Layered Double Hydroxide as Bifunctional Electrochemical Catalyst

Gao

Long

Han

et al. 2017

J. Electrochem. Soc.

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Reducing overpotential and increasing current density remain a great challenge for promoting the application of transition metalsbased layered double hydroxides (LDHs). Herein, Ni nanoparticles (∼10 nm) decorated NiFe LDH ultrathin (thickness: ∼2 nm) nanosheets (Ni NP/NiFe LDH) were successfully synthesized which exhibited advanced electrocatalytic activity and long-term stability on both oxygen evolution reaction (OER) and urea oxidation reaction (UOR). The onset potentials for OER and UOR are 1.50 V and 1.34 V, respectively, both are lower than NiFe LDH under the same conditions. Moreover, the peak current density of UOR was 300 mA/cm 2 , which is much larger than reported precious-metal free UOR catalysts. The excellent catalytic performance of Ni NP/NiFe LDH composite for OER and UOR is proposed to result from the abundant exposed active sites, small charge transfer resistance, and the synergistic effects between NiFe LDH and anchored Ni nanoparticles. This work provides inspiring ideas and helpful guidelines in design of low-cost but highly efficient electrochemical catalysts. The global energy crisis and environmental contamination have prompted intense research into the development of sustainable energy conversion and storage systems.1-10 Water splitting and direct urea fuel cell (DUFC) as promising approaches to produce clean energy recyclable, have been widely investigated recently. Nevertheless, oxygen evolution reaction (OER: 2H 2 O === O 2 + 4H + + 4e − ) suffers from a sluggish kinetics owing to a 4e-transfer process, which is frequently an obstacle to the whole water splitting. Same as OER, urea oxidation reaction (UOR: CO(NH 2 ) 2 + H 2 O === N 2 + 3H 2 + CO 2 ) is also under a multistep proton-coupled electron transfer process, which remains to be a great challenge for DUFC. As a consequence, the sluggish kinetics of OER and UOR lead to considerable overpotential and decrease the efficiency of energy conversion and storage. To achieve efficient energy conversion, much effort has been devoted to the research for robust yet stable electrochemical catalysts with reduced overpotentials. Precious metal based catalysts have shown significant electrocatalytic properties, 11-13 but their high cost and scarcity hamper the commercialization of the technique. Therefore, developing functional nanomaterials composed of cost-effective and abundant elements are on great demand.Owing to the unique physicochemical properties (e.g. tunable metal species/ratios, and exchangeable interlayer spacings, etc.), layered double hydroxides (LDHs) [23][24][25][26][27] and among which, NiFe LDH showed the best performance.28 Nevertheless, reducing the overpotential and increasing the current density remain under intensive pursuit for promoting the application of NiFe LDH. For example, the introduction of conductive materials (graphene, carbon nanotube, etc.) into LDH systems can improve the conductivity of the catalysts 21,22 and hence further enhance their catalytic performance. Herein, we report a bifunctional catalyst ...

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“…It should be noticed that abnormal broadening of the (1 0 l) reflection lines (l / = 0) cannot be attributed to the crystallite size alone. Structural disorder plays an important role in this broadening [32,33]. Structural disorder in Ni(OH) 2 can provide an easier path for the diffusion of protons within the NiO layers and can help lower the free energy by increasing the entropy, which can in turn increase the electrochemical reaction rate [10,12].…”

Section: Xrdmentioning

confidence: 99%

Comparative structural and electrochemical study of high density spherical and non-spherical Ni(OH)2 as cathode materials for Ni–metal hydride batteries

Shangguan

Chang

Tang

et al. 2011

Journal of Power Sources

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:Nickel hydroxide High-density Nickel-metal hydride batteries High-rate discharge Cathode materials a b s t r a c tIn this paper we compare the behavior of non-spherical and spherical ␤-Ni(OH) 2 as cathode materials for Ni-MH batteries in an attempt to explore the effect of microstructure and surface properties of ␤-Ni(OH) 2 on their electrochemical performances. Non-spherical ␤-Ni(OH) 2 powders with a high-density are synthesized using a simple polyacrylamide (PAM) assisted two-step drying method. X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), thermogravimetric/differential thermal analysis (TG-DTA), Brunauer-Emmett-Teller (BET) testing, laser particle size analysis, and tap-density testing are used to characterize the physical properties of the synthesized products. Electrochemical characterization, including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and a charge/discharge test, is also performed. The results show that the non-spherical ␤-Ni(OH) 2 materials exhibit an irregular tabular shape and a dense solid structure, which contains many overlapped sheet nano crystalline grains, and have a high density of structural disorder and a large specific surface area. Compared with the spherical ␤-Ni(OH) 2 , the non-spherical ␤-Ni(OH) 2 materials have an enhanced discharge capacity, higher discharge potential plateau and superior cycle stability. This performance improvement can be attributable to a higher proton diffusion coefficient (4.26 × 10 −9 cm 2 s −1 ), better reaction reversibility, and lower electrochemical impedance of the synthesized material.

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Structural defects and electrochemical reactivity of β-Ni(OH)2

Cited by 213 publications

References 9 publications

Raman and Infrared Spectroscopy of α and β Phases of Thin Nickel Hydroxide Films Electrochemically Formed on Nickel

Raman and Infrared Spectroscopy of α and β Phases of Thin Nickel Hydroxide Films Electrochemically Formed on Nickel

Ni Nanoparticles Decorated NiFe Layered Double Hydroxide as Bifunctional Electrochemical Catalyst

Comparative structural and electrochemical study of high density spherical and non-spherical Ni(OH)2 as cathode materials for Ni–metal hydride batteries

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