Preparation Of NiO Nanoparticles Research Articles

Biomass extract-mediated preparation of magnesium-doped nickel oxide nanoparticles and their in vitro bioactivities assessment

Biomass extract-mediated fabrication of metal oxide nanoparticles received significant attention in material research because it is eco-friendly, cost-effective, and easy to scalability. Here, the fabrication of Boerhavia diffusa leaf extract (BDE)-mediated magnesium-doped nickel oxide nanoparticles (Mg-doped-NiO-BDE) and their in vitro bioactivities are reported. Several characterization procedures are used to characterize the prepared NiO nanoparticles. Field emission scanning electron microscopy and transmission electron microscopy images exhibit that the Mg-doped-NiO-BDE are distorted spherical. The X-ray diffraction showed that the average crystallite sizes of the nanoparticles are around 51–55 nm. X-ray diffraction, X-ray photoelectron spectroscopy, and energy-dispersive X-ray spectroscopy analysis results confirm that the NiO is produced, and Mg-doping has occurred in the adopted reaction condition. The doped NiO NPs exhibit broad-spectrum antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), as well as antifungal action against Aspergillus niger (A. nigar). The antioxidant, anti-inflammatory, and anti-diabetic efficiencies of doped-NiO NPs (concentration = 400 μg/mL) are around 65 %, 89 %, and 87 %, respectively. The Mg-doped-NiO-BDE nanoparticles show around 75 % viability against the human lung cancer cell line (A459) with a concentration of up to 100 μg/mL, while the IC50 value is 185.6 μg/mL. The scratch test is executed with the mouse fibroblast cells (L929) in which doped-NiO NPs exhibit around 36 % wound-closing ability. The above results signify that the fabricated Mg-doped-NiO-BDE is a potent bioactive material that could be used for biomedical applications.

Structural, optical and magnetic properties of Ni1-2xMgxRuxO nanoparticles

Ni1-2xMgxRuxO (x = 0, 0.005, 0.01, 0.02, 0.04 and 0.08) nanoparticles were synthesized via the coprecipitation method. The prepared NiO nanoparticles are characterized by thermogravimetric analysis (TGA) that reveal the successful codoping and assure the thermal stability of the samples beyond 550 ˚C. X-ray powder diffraction (XRD) confirms the formation of the NiO cubic structure with RuO2 secondary phase that appears at high codoping concentrations. As the codoping concentration increases, the lattice parameter increases and crystallite size decreases. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) show slightly agglomerated pseudo-spherical nanoparticles. Energy dispersive x-ray (EDX), X-ray photo-induced spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy reveal the elemental composition and deviation from perfect stoichiometry. UV–vis and photoluminescence (PL) spectroscopies are utilized to study the optical properties, where Ni0.84Mg0.08Ru0.08O nanoparticles show the highest direct band gap energy and lowest Urbach energy and electron-phonon interaction. Vibrating sample magnetometer (VSM) shows single domain nanoparticles, such that the coercivity and magnetocrystalline anisotropy decrease as the size decreases. The bound magnetic polaron model was utilized to investigate the weak ferromagnetism exhibited by the prepared Ni1-2xMgxRuxO nanoparticles.

NiO nanoparticles decorated hexagonal Nickel-based metal-organic framework: Self-template synthesis and its application in electrochemical energy storage

A one-pot solvothermal strategy and subsequent calcination were proposed for fabricating a composite of NiO nanoparticles on hexagonal Ni-based metal–organic framework (Ni-MOF) (Ni-MOF@NiO). The prepared NiO nanoparticles on the hexagonal Ni-MOF not only improves the electrical conductivity and increases redox active sites, but also prevents the agglomeration of NiO nanoparticles. In particular, highly dispersed and small-sized NiO nanoparticles on the hexagonal Ni-MOF facilitates the migration of electrolyte ions, and the pseudocapacitive performance is evaluated through electrochemical measurements. At 0.5 A g−1, the Ni-MOF@NiO composite shows a specific capacitance of up to 1192.7 F g−1 and a high capacity retention (93.23% over 5000 cycles) in 3 M KOH. Moreover, the Ni-MOF@NiO nanoparticles and activated carbon are assembled into aqueous devices with a maximum energy density of 62.2 Wh kg−1. These results indicate the potential of Ni-MOF@NiO composite as an electrode material for application in supercapacitors. Additionally, the method of synthesizing Ni-MOF@NiO in this study can be used to synthesize other MOF@metal oxide materials for electrochemical energy storage and other related applications.

Excellent Oxygen Evolution Reaction of Activated Carbon-Anchored NiO Nanotablets Prepared by Green Routes.

A sustainable and efficient electrocatalyst for the oxygen evolution reaction (OER) is vital to realize green and clean hydrogen production technology. Herein, we synthesized the nanocomposites of activated carbon-anchored nickel oxide (AC-NiO) via fully green routes, and characterized their excellent OER performances. The AC-NiO nanocomposites were prepared by the facile sonication method using sonochemically prepared NiO nanoparticles and biomass-derived AC nanosponges. The nanocomposites exhibited an aggregated structure of the AC-NiO nanotablets with an average size of 40 nm. When using the nanotablets as an OER catalyst in 1 M KOH, the sample displayed superb electrocatalytic performances, i.e., a substantially low value of overpotential (320 mV at 10 mA/cm2), a significantly small Tafel slope (49 mV/dec), and a good OER stability (4% decrease of overpotential after 10 h). These outstanding OER characteristics are considered as attributing to the synergetic effects from both the ample surface area of the electrochemically active NiO nanoparticles and the high electrical conductivity of the AC nanosponges. The results pronounce that the fully ecofriendly synthesized AC-NiO nanotablets can play a splendid role as high-performance electrocatalysts for future green energy technology.

Rapid laser fabrication of Nickel oxide nanoparticles for UV detector

In the present work, silicon-based Nickel oxide heterojunction photodetectors was manufactured via two-step. First, the NiO was directly synthesised by laser ablation (Model Nd:YAG with a wavelength of 1064 nm) in the liquid approach of a pure Ni target: typically with various number of pulses at constant laser energy. Second, the prepared NiO colloidal was then deposited on a silicon wafer surface by a dip-coating method. The impacts of laser pulses on the NiO particles properties were in briefly presented. The synthesis of NiO NPs with a good-nanocrystalline structure in deionized water was proved. The dominated shape of the NiO NPs was quasi-spherical and their concentration was observed to be affected by the laser conditions. FTIR spectral results proved the formation of NiO bonds at 526 cm−1and 507 cm−1. The optical energy bandwidth decreases from 3.75 to 3.6 eV as the laser pulses increase. The introduction of the prepared NiO nanoparticles into silicon showed a well-performance for UV detection. The nanostructured NiO/Si heterojunction photodetector exhibited clear rectifying I-V behaviour in the dark condition and showed prominent photovoltaic properties under illumination. The contrast ratio of the fabricated detector increases with an increasing number of laser pulses. It demonstrated a maximum value of the responsivity and detectivity 0.7 A/W, 63 × 1012 cm. Hz1/2. W−1, respectively under 330 nm UV light illumination.

Simultaneous detection of dopamine, tyrosine and ascorbic acid using NiO/graphene modified graphite electrode

In this work, an electrochemical sensor is fabricated by decorating the surface of graphite electrode with NiO/graphene (NGMG) nanoparticles and employed for the detection of dopamine (DA), tyrosine (Tyr) and ascorbic acid (AA). The structure and morphology of prepared NiO nanoparticles are examined by XRD,SEM, FTIR and Raman techniques. The electrochemical properties have been investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperommety. The modified electrode is prepared by a simple drop casting method. The electrode shows good electro catalyticactivity towards oxidation of DA, Tyr and AA. It successfully separates the oxidation current signals of AA, DA and Tyr into clearly visible three distinct oxidation peaks compared to a single, overlapped oxidative peak on bare graphite electrode. The peak potential difference between AA-DA, DA-Tyr and AA-Tyr is 228 mV, 303 mV and 565 mV respectively in cyclic voltammetry (CV) studies and the corresponding peak potential separations are 243 mV, 318 mV and 561 mV respectively in differential pulse voltammetry (DPV). It is found that oxidation mechanism of DA, AA and Tyr on NGMG are different owing to a different type of interaction of the modified layer with the bio-analytes. The modified electrode, NGMG has high selectivity and sensitivity in addition to other factors like low cost, convenient and a hassle free electrochemical method for simultaneous determination of DA, AA and Tyr in their ternary mixture.

Structural and optical properties of nickel oxide nanoparticles: Investigation of antimicrobial applications

The green synthesis of nickel oxide nanoparticles were prepared by microwave combustion method. The prepared NiO material was annealed at 200°C & 700°C. The XRD pattern confirms the very good crystallinity of the material and the average crystallite size was found to be 20 nm and 30 nm respectively for both NiO samples. However, the morphology of samples were studied using SEM analysis and shows spherical shape with agglomeration matrix. In particular, the SEM images of prepared NiO nanoparticles were dried at 200 °C and annealed at 700 °C which gives the average particle size of 19 nm and 30 nm. Moreover, FTIR study was carried out to identify the functional group present in prepared samples extensively. In that view, the UV–vis absorption spectra of bandgap values are calculated. Likewise, EDX pattern were shown the composition element present in the compound. The antibacterial study reveals that both the samples shows good antibacterial activity on both gram positive and gram-negative bacteria's. Hence, this green synthesized NiO material can be used for antibacterial applications.

Phytogenic Generation of NiO Nanoparticles Using Stevia Leaf Extract and Evaluation of Their In-Vitro Antioxidant and Antimicrobial Properties.

In the present study, economically viable NiO nanoparticles were produced by biogenic preparation using stevia leaf broth and their in-vitro antioxidant and antimicrobial activities were evaluated. The properties of the prepared NiO nanoparticles were confirmed by analytical techniques such as Ultraviolet-Visible (UV-Vis), X-ray diffraction (XRD), FE-SEM, and Fourier transform infrared spectroscopy (FTIR) analyses. Morphological studies using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the size of synthesized nanoparticles ranged from 20 to 50 nm, most of which were spherical and few of which were agglomerated. The role of the biological moieties, which reduce and cap the nanoparticles, was studied using FTIR analysis. The prepared nanoparticles strongly inhibited gram-negative bacteria, which is a camper with gram-positive bacteria and fungi. Furthermore, it performs an effective in-vitro activity through α,α-diphenyl-β-picrylhydrazyl (DPPH) reduction. Thus, it can be concluded that the effective and easy green synthesis process used for NiO nanoparticles provides potential antimicrobial agents against multidrug-resistant microbes.

Exploration of Catalytic Activity of Quercetin Mediated Hydrothermally Synthesized NiO Nanoparticles Towards C–N Coupling of Nitrogen Heterocycles

A new approach towards the preparation of phase pure NiO nanoparticles via quercetin mediated hydrothermal method is proposed in this work. The performance of quercetin as capping agent is found to be good. The XRD and SEM results confirm that the NiO nanoparticles prepared with quercetin are smaller in size and have refined morphology than that prepared without quercetin. Thermal stability, elemental composition and particle size of prepared nanoparticles have been revealed by TG-DSC, EDAX and HR-TEM analysis respectively. N2 adsorption–desorption isotherm (BET) analysis was done to reveal specific surface area. The prepared NiO nanoparticles act as cost effective, environmental friendly and efficient catalyst for the C–N cross coupling of indole and electron deficient pyrrole, under very mild reaction conditions. The catalytic system is able to tolerate many functional groups with different electronic and structural properties. Hence the present catalytic system may be possibly applied in large scale synthesis.

Preparation of NiO nanoparticles in mesoporous silica via eutectic freezing and freeze-drying of aqueous precursor salts

Abstract Immobilization of small metal oxide particles on a solid support by impregnation with solutions of metal salts is a common route of catalyst preparation. Here we explore a modification of this route, based on eutectic freezing of the aqueous precursor salts in the pores of SBA-15, and removal of water/ice by freeze-drying. The two-solvents method was used to selectively fill the pore space of SBA-15 with precursor salts (nickel acetate or nitrate). A morphological and structural analysis of the nickel oxide formed in the pores after thermal decomposition of the salts was performed and compared to samples obtained via conventional solvent evaporation. Immobilized NiO nanocrystallites prepared via eutectic freezing appeared in two morphologies: (a) rodlike particles of ca 5 nm diameter, i.e., somewhat smaller than the pore diameter of SBA-15 (7 nm); (b) species detectable by powder XRD and energy-dispersive X-ray spectroscopy (EDXS), but not by TEM. Nitrogen adsorption isotherms are sensitive to the distribution of NiO in the pores: Pore blocking effects appear in the desorption branch for samples containing rodlike NiO particles, but not in samples in which no particles are detectable by TEM.

Synthesis and crystal structure of [Ni(Amgu)2]X2 – Novel solid-state precursors for NiO nanoparticles

Aminoguanidine (Amgu) nickel complexes containing nitrate and chloride with the formula [Ni(Amgu)2]X2 [X = NO3– (1) and Cl− (2)] were prepared and characterized by analytical, Fourier-transform infrared (FTIR) spectroscopic and single crystal X-ray diffraction studies. Compound 1 crystallized in the triclinic crystal system of space group P-1 with Z = 1, and compound 2 crystallized in the monoclinic crystal system of space group P21/n with Z = 2. Both compounds have square planar geometry with two neutral aminoguanidine ligands acting as trans N,N-chelators. The N-N stretching of aminoguanidine ligands was corroborated by the FTIR spectroscopic peak observed at 1139 cm−1. NiO nanoparticles were obtained by the decomposition of compounds 1 and 2, which were calcined at 400 °C for 4 h. The powder X-ray diffraction (PXRD) patterns confirmed that the prepared NiO nanoparticles had high purity and crystallinity. Therefore, these complexes may be used as solid-state precursors for the preparation of NiO nanoparticles owing to their low temperatures of decomposition.

Pyrolysis and Oxidation of Asphaltene-Born Coke-like Residue Formed onto in Situ Prepared NiO Nanoparticles toward Advanced in Situ Combustion Enhanced Oil Recovery Processes

Pyrolysis and oxidation of asphaltene-born coke-like residue formed onto ex situ and in situ prepared NiO nanoparticles as initial steps toward developing advanced in situ combustion enhanced oil recovery (EOR) processes were studied. The in situ synthesized NiO nanoparticles in heavy oil matrix, containing coke-like residue, were characterized by X-ray diffraction, Brunauer–Emmett–Teller, field-emission scanning electron microscopy, and energy-dispersive X-ray mapping techniques. The pyrolysis and postpyrolysis oxidation of the coke residue were investigated by temperature-programmed pyrolysis (TPP) and temperature-programmed oxidation (TPO) methods, respectively. Oxidation kinetics of the coke residue was described by the Kissinger–Akahira–Sunose isoconversional method. The results showed a higher percentage of coke residue on the in situ prepared nanoparticles than the ex situ employed ones. Eventually, during the TPP of the coke residue, the amount of carbon oxides released per total amount of the cok...

P.1.e.004 - Vitamin D3 exerts a protective effect on glucocorticoid-induced neurotoxicity in rats via modulation of signaling through receptor activator of NF-κB

Aminoguanidine (Amgu) nickel complexes containing nitrate and chloride with the formula [Ni(Amgu)2]X2 [X = NO3– (1) and Cl− (2)] were prepared and characterized by analytical, Fourier-transform infrared (FTIR) spectroscopic and single crystal X-ray diffraction studies. Compound 1 crystallized in the triclinic crystal system of space group P-1 with Z = 1, and compound 2 crystallized in the monoclinic crystal system of space group P21/n with Z = 2. Both compounds have square planar geometry with two neutral aminoguanidine ligands acting as trans N,N-chelators. The N-N stretching of aminoguanidine ligands was corroborated by the FTIR spectroscopic peak observed at 1139 cm−1. NiO nanoparticles were obtained by the decomposition of compounds 1 and 2, which were calcined at 400 °C for 4 h. The powder X-ray diffraction (PXRD) patterns confirmed that the prepared NiO nanoparticles had high purity and crystallinity. Therefore, these complexes may be used as solid-state precursors for the preparation of NiO nanoparticles owing to their low temperatures of decomposition.

In-situ upgrading of reservoir oils by in-situ preparation of NiO nanoparticles in thermal enhanced oil recovery processes

In-situ combustion (ISC) in the presence of catalytic metal oxide nanoparticles is a promising enhanced oil recovery process for heavy oil reservoirs. A proper method for uniform distribution of the nanoparticles in the reservoir fluids is in-situ synthesis of the nanomaterials. Precursor metal ionic aqueous solutions and heavy oil form water/oil emulsions, downstream of the combustion front, by the aid of asphaltenes and resins. Upon heating, the nanoparticles are formed, on which asphaltenes are adsorbed and pyrolyzed to provide the fuel for a stable ISC front. NiO nanoparticles were synthesized via the in-situ synthesis process. Ni(NO3)2·6H2O aqueous solution was dispersed in heavy oil model solutions of asphaltenes in toluene-vacuum gasoil. The droplet size, stability, and interface elasticity of the emulsions were monitored by changing the precursor salt concentration, salt solution/oil ratio, and temperature and pressure. Bottle test, micropipette test, microscope imaging, and equilibrium and dynamic IFT measurements were used to characterize the emulsions. The stable emulsions were exposed to high-temperature and high-pressure conditions to deliver nanoparticles. The in-situ prepared coked nanoparticles were characterized by XRD, FTIR, HRTEM, and TGA techniques and compared with ex-situ prepared NiO nanoparticles. Prior and subsequent to the in-situ synthesis, the kinematic viscosity of the model oil, as an upgrading index, was measured. It is found that the emulsions droplet size increases with the precursor salt concentration, at constant salt solution/oil ratios, leading to instability of the emulsions. An optimum value is found for the salt solution/oil ratio, at constant precursor molarities, resulting in stable emulsions. Compared to ex-situ prepared nanoparticles, the in-situ synthesized NiO nanoparticles exhibit around 48% higher coke formation tendency and shift the coke combustion temperature by about 130°C downward. Furthermore, the viscosity of the model oil decreases by 2–8% during the in-situ synthesis procedure, showing an in-situ upgrading potential for the process.

A study of frequency dependent electrical and dielectric properties of NiO nanoparticles

Nickel oxide nanoparticles were synthesized using low cost sol-gel method. The structure of as prepared NiO nanoparticles has been confirmed from X-ray diffraction (XRD), scanning electron microscope with energy dispersive X-ray (SEM and EDX) spectroscopic analysis. The electrical and dielectric properties were characterized by complex impedance spectroscopy as a function of frequency at different temperatures. To study the dielectric behavior of the nanoparticles different plots like Nyquist plot, modulus plot and Bode plot were used. Also the frequency dependent ac conductivity is analyzed and the activation energy is calculated. The dielectric constant and dielectric loss as a function of frequency at various temperatures are also studied.

Room temperature CO oxidation catalyzed by NiO particles on mesoporous SiO2 prepared via atomic layer deposition: Influence of pre-annealing temperature on catalytic activity

We prepared NiO nanoparticles on mesoporous SiO2 using atomic layer deposition and additionally annealed the prepared samples at four different temperatures (300–750°C) under dry air. NiO nanoparticles had lateral sizes less than ∼2nm up to 600°C, whereas annealing at a higher temperature (750°C) resulted in a significant agglomeration of NiO, with the formation of 30nm-sized particles. Annealing at a higher temperature resulted in a reduction in carbon impurities in the annealing temperature range of 300–600°C. Among the four samples annealed at different temperatures, the 450°C-annealed sample showed the highest CO oxidation activity at room temperature. CO oxidation reactivity of this sample initially decreased with reaction time; however, the deactivation became less pronounced over time, with maintenance of 60% of the initial activity of this catalyst after 680min. Furthermore, 450°C-annealing of used catalyst resulted in full recovery of the initial CO oxidation reactivity. These results suggest that ALD followed by annealing is a promising strategy for the fabrication of highly efficient and stable catalysts consisting of nanoparticles incorporated in the mesopores of a high-surface area support.

High-Performance Solution Processed Inorganic Quantum-Dot LEDs

In this research paper, fabrication of novel CdSe\ZnS QD-LEDs with solution processing method is presented, and the impact of trap energy levels in the electron and hole transport levels on these QD-LEDs brightness is investigated. Two types of QD-LEDs are fabricated with ITO as the transparent anode electrode, NiO nanoparticles as the hole transport layer (HTL), CdSe\ZnS QDs as the luminescent layer, ZnO:Ga as the electron transport layer (ETL), and Al as the cathode electrode. The NiO nanoparticles are synthesized by the sol-gel or alternatively the electrochemical method. Formation of different trap levels is observed in the crystal structures of the NiO nanoparticles synthesized by each of these methods. Considering the electrochemically prepared NiO nanoparticles, it is found that the density of trap levels is higher in the crystal structure of the NiO nanoparticles synthesized by sol-gel method, and the device fabricated by the latter material shows higher performance. Calculation of the electronic structure of ZnO:Ga by DFT methods (GGA-PBE) indicates that doping of Ga in the structure of crystalline ZnO creates new energy levels in conduction band and intermediate bands at the bandgap of ZnO host. It facilitates electron injection from Al cathode to the ZnO:Ga ETL layer and from this layer to the QD-luminescent layer. The fabricated devices show turn-on lower voltages than 5 V in which a peak brightness of 500 and 340 cd·m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> is measured for the LEDs fabricated with sol-gel and electrochemically synthesized NiO nanoparticles, respectively.

Effects of Mn on the magnetic and optical properties and photocatalytic activities of NiO nanoparticles synthesized via the simple precipitation process

Abstract Pure and Mn doped NiO nanoparticles have been successfully synthesized via the simple precipitation process. The XRD and TEM studies have confirmed that the prepared NiO nanoparticles sizes decreased with the manganese insertion into nickel oxide. The observed antiferro to superpara and ferromagnetic transition on Mn doping in NiO is understood on the basis of Mn occupying Ni sites, and breaking the translational symmetry of the parent antiferromagnetic correlation. The measured band gap energies (Eg = 3.78, 3.81, 3.84 and 3.90 eV) increased with decreasing particles size, which indicated the quantum confinement effect. The broad visible emission at 527 nm originates from the deep levels of the prepared NiO nanoparticles and is due to the presence of Vo and Ni(in) defects. The photocatalytic degradation of the methyl orange dye was studied for the prepared pure and doped samples, and the mechanism has been discussed.

Preparation of NiO nanoparticles from Ni(OH)2·NiCO3·4H2O precursor by mechanical activation

A mechanical activation process was introduced as a facile method for producing nickel oxide nanopowders. The precursor compound Ni(OH)2·NiCO3·4H2O was synthesized by chemical precipitation. The precursor was milled with NaCl diluent. A high-energy ball milling process led to decomposition of the precursor and subsequent dispersal in NaCl media. Nickel oxide nanocrystalline powders were produced by subsequent heat treatment and water washing. Milling rotation speed, milling time, ball-to-powder ratio (BPR), and nickel chloride-to-precursor ratio were introduced as influential parameters on the wavelength of maximum absorption (λ max). The effects of these parameters were investigated by the Taguchi method. The optimum conditions for this study were a milling rotation speed of 150 r/min, a milling time of 20 h, a BPR of 15/1, and a NaCl-to-powder weight ratio (NPR) of 6/1. In these conditions, λ max was predicted to be 292 nm. The structural properties of the samples were determined by field emission scanning electron microscopy, X-ray diffraction, and energy dispersive spectrometry.

Intrinsic shape analysis of X-ray diffraction using Stokes deconvolution

A deconvolution algorithm is proposed for X-ray diffraction profile analysis. The stability of the algorithm and the influence of the regularization parameter in the deconvoluted results were investigated with respect to the full width at half maximum (FWHM) and the signal to noise ratio. Reliability of the deconvolution profile was estimated. A simple algorithm is proposed that allows obtaining knowledge of the behaviors of the intrinsic physical profile with different instrumental and measured ones. The experimental powder diffraction of prepared NiO nanoparticles has been analyzed by the proposed technique. The algorithm applied to determine the microstructure characteristics compared to those of Sherrer and Stoke’s methods. The method has the advantage that the grain-size or microstrain can be calculated directly without using normal approximation correction and the success of this technique is dependent on the value of the regularization parameter.