Structural characterization of nickel oxide/hydroxide nanosheets produced by CBD technique

Taşköprü, T.; Zor, Muhsin; Turan, Evren

doi:10.1016/j.materresbull.2015.05.032

Cited by 22 publications

(6 citation statements)

References 32 publications

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“…Oxidation states, deduced from XANES edge position and Ni-O bond distance, scatter within error around +2 for samples Ni-AP to Ni-600, as expected for both Ni(OH) 2 and NiO. A phase transition from Ni(OH) 2 to NiO has been reported for samples produced under a variety of conditions 43,44. In our sample series the Ni(OH) 2 -to-NiO phase transition occurs as an amorphous-to-amorphous transition, allowing us to directly compare Ni sites in amorphous Ni(OH) 2 and NiO coordination environments.…”

supporting

confidence: 67%

Structural Evolution in Photodeposited Nickel (oxy)hydroxide Oxygen Evolution Electrocatalysts

Schoen

Randell

Calderon

et al. 2020

ACS Appl. Energy Mater.

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Amorphous metal oxides expand the range of material parameters significantly compared to their crystalline counter parts. However, predictions of the exact nature of the amorphous phase and its effect on material properties are still elusive. Thorough structureproperty investigations of well-known model systems are thus necessary before predictive control of useful material properties is obtained. In this work, we fabricate a series of photodeposited nickel (oxy)hydroxide (NiO x ) thin films and anneal them at temperatures up to 1000 • C. EXAFS, XRD and XPS are used to determine the local structure, allowing us to correlate it to measured electrochemical properties. We find an amorphous Ni(OH) 2 -like local structure for annealing conducted below 250 • C, followed by an amorphous-to-amorphous phase transition to a NiO-like structure by 300 • C, thus supplying evidence for different 1 amorphous polymorphs in this Ni-O system. Above 400 • C a cubic NiO XRD diffraction pattern is detected. Electrochemically, we find a stepwise increase of the onset overpotential at this transition, indicating a change in potential-determining step and possibly OER reaction mechanism. The Tafel slope decreases linearly with annealing temperature, which we attribute to a decrease in (Ni)OOH reaction intermediary coverage, supported by in-operando UV-Vis electrochromism. Furthermore, we find that the (Ni)OOH coordination is increasingly strained with annealing temperature, which manifests in higher electrochromic coloring rates and lower binding energies. We identify this as the root cause of the lowered intermediary coverage. Thus, nano-crystalline NiO should kinetically be a superior catalyst to amorphous Ni(OH) 2 . However, at our benchmarking value of 10 mA cm −2 the amorphous material exhibits lower overpotential, due to a combination of lower onset potential, large chemically active surface area and mass transport limitations under our conditions.

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supporting

confidence: 67%

Structural Evolution in Photodeposited Nickel (oxy)hydroxide Oxygen Evolution Electrocatalysts

Schoen

Randell

Calderon

et al. 2020

ACS Appl. Energy Mater.

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“…Similarly, NiO showed three characteristic broad vibrational bands corresponding to the one-phonon (1P) mode at 497.4 cm −1 as well as the two-phonon (2P) modes at 726 cm −1 (transverse optical) and 1068 cm −1 (longitudinal optical). The broadening of the Raman bands in the case of NiO suggests the presence of structural defects or surface effects, both of which are well documented in the literature [ 40 , 41 ]. In such cases, the 1P band becomes pronounced with concomitant disappearance of the 906 cm −1 band [ 41 ].…”

Section: Resultsmentioning

confidence: 83%

“…XRD pattern obtained from the black powder confirmed the face-centered cubic phase of NiO (JCPDS no 78-0423) with the most intense (200) plane supporting its 2D morphology, while the absence of any additional peak supporting a phase pure material. The Raman spectrum of β -Ni(OH) 2 showed peaks at 312.6 and 448.3 cm −1 which are the characteristic lattice vibrational Eg and A 1g modes of the β-phase of nickel hydroxide ( Figure 2 b) [ 39 , 40 ]. Similarly, NiO showed three characteristic broad vibrational bands corresponding to the one-phonon (1P) mode at 497.4 cm −1 as well as the two-phonon (2P) modes at 726 cm −1 (transverse optical) and 1068 cm −1 (longitudinal optical).…”

Section: Resultsmentioning

confidence: 99%

L-Cysteine as an Irreversible Inhibitor of the Peroxidase-Mimic Catalytic Activity of 2-Dimensional Ni-Based Nanozymes

et al. 2021

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The ability to modulate the catalytic activity of inorganic nanozymes is of high interest. In particular, understanding the interactions of inhibitor molecules with nanozymes can bring them one step closer to the natural enzymes and has thus started to attract intense interest. To date, a few reversible inhibitors of the nanozyme activity have been reported. However, there are no reports of irreversible inhibitor molecules that can permanently inhibit the activity of nanozymes. In the current work, we show the ability of L-cysteine to act as an irreversible inhibitor to permanently block the nanozyme activity of 2-dimensional (2D) NiO nanosheets. Determination of the steady state kinetic parameters allowed us to obtain mechanistic insights into the catalytic inhibition process. Further, based on the irreversible catalytic inhibition capability of L-cysteine, we demonstrate a highly specific sensor for the detection of this biologically important molecule.

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“…This could be attributed to the first‐order longitudinal optical (LO) mode of NiO. It was suggested that the first‐order LO phonon scattering, which occurred in NiO is due to nickel vacancy defects . Besides that, a slight shifting in wavelength can be seen for the first‐order LO which might be due to strained lattice or reduced size to quantized lattice vibrations .…”

Section: Resultsmentioning

confidence: 88%

Synthesis and Characterization of NiO Nano‐Spheres by Templating on Chitosan as a Green Precursor

et al. 2016

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In this study, nickel oxide was prepared through the calcination of extrusion dripped chitosan/nickel nitrate beads. The morphology and structural properties of the products were studied using various characterization techniques. Uniformly distributed nickel oxide was formed as observed from the studies of surface morphology where the processing parameters play a huge role on the resulting morphology. TEM results have shown that nickel oxide with crystallite sizes of 10–30 nm was obtained. The Fourier-transform infrared spectra studies show an intense peak at 525 cm−1, which is attributed to the vibration of Ni–O bond. Furthermore, the XRD results show NiO diffraction peaks correspond to (111), (200), (220), (311), and (222) which indicates that a bunsenite structure with a face-centered cubic phase was produced in this study. The usage of 500°C as the lower limit in this study is justified due to the complete removal of the templating material as seen in the thermalgravimetric analysis studies. Furthermore, it was obtained that the largest surface area of nickel oxide synthesized using this technique is 48.024 m2/g with pore sizes of 19.843 nm. The usage of chitosan as a green template for the synthesis of nanoparticles has shown promising results which allows a more economical and sustainable approach for the fabrication of nanomaterials

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Structural characterization of nickel oxide/hydroxide nanosheets produced by CBD technique

Cited by 22 publications

References 32 publications

Structural Evolution in Photodeposited Nickel (oxy)hydroxide Oxygen Evolution Electrocatalysts

Structural Evolution in Photodeposited Nickel (oxy)hydroxide Oxygen Evolution Electrocatalysts

L-Cysteine as an Irreversible Inhibitor of the Peroxidase-Mimic Catalytic Activity of 2-Dimensional Ni-Based Nanozymes

Synthesis and Characterization of NiO Nano‐Spheres by Templating on Chitosan as a Green Precursor

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