Size Of Nickel Oxide Nanoparticles Research Articles

Biological applications of green synthesized zinc oxide and nickel oxide nanoparticles mediated poly(glutaric acid-co-ethylene glycol-co-acrylic acid) polymer nanocomposites

The metal oxide nanoparticles (NPs), zinc oxide (ZnO) and nickel oxide (NiO) were synthesized using Sterculia foetida (S. foetida) leaf extract by solution combustion method. The Poly (glutaric acid-co-ethylene glycol-co-acrylic acid (GEA)) hydrogel was prepared using three different monomers such as glutaric acid (G), ethylene glycol (E) and acrylic acid (A). The zinc oxide (ZnO) and nickel oxide (NiO) nanoparticles were introduced into GEA hydrogel and the polymer nanocomposites GEA-ZnO and GEA-NiO were obtained. The UV–visible spectroscopy (UV) peak observed at 275 nm and 360 nm for GEA-ZnO and GEA-NiO polymer nanocomposites. The Fourier Transform Infrared (FT-IR) spectral data obtained at 414 cm−1 confirmed the presence of nanoparticles in the hydrogel. The size of the nanoparticles were confirmed through Scanning Electron Microscopy (SEM) and Transmission Electron Microscope (TEM) analysis. The size of the zinc oxide nanoparticles (ZnO NPs) introduced in GEA-ZnO polymer nanocomposite was 30–35 nm and the size of nickel oxide nanoparticles (NiO NPs) introduced in GEA-NiO nanocomposite was 27–33 nm. The percentage of zinc oxide (ZnO) and nickel oxide (NiO) were reported in Energy Dispersive X-ray Analysis (EDAX) spectrum. Where the percentage of zinc (Zn) is 2.22% and nickel (Ni) is 2.7%. The thermal stability of the nanoparticles in the hydrogel was assessed by Thermo gravimetric analysis (TGA). Beyond 450 °C there was no change in the Thermo Gravimetric Analysis (TGA) peak of GEA-NiO polymer nanocomposite and found with nil weight loss. The antibacterial activity was performed using Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis) gram positive bacterial strains and Escherchia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) gram negative bacterial strains. The gram positive bacteria showed highest antibacterial activity than gram negative bacteria at highest concentration 100 μg/ml towards polymer nanocomposites.

Performance of trans perovskite solar cells improved by finely adjusting the particle size of nickel oxide nanoparticles through pH value

As a low-cost, high stable hole transport material, nickel oxide has been widely used in inverted structure perovskite solar cells in recent years. By far, the most common method of preparing nickel oxide hole transport layers is spin-coating pre-prepared nickel oxide nanoparticles (NiO<sub><i>x</i></sub> NPs), which puts forward high requirement for the particle sizes and solution processing capabilities of NiO<sub><i>x</i></sub> NPs. In this work, the sizes of NiO<sub><i>x</i></sub> NPs are precisely controlled by adjusting the pH value of the system in the synthesis process, and high-quality nickel oxide hole transport layers are then prepared. The experimental results exhibit that the NiO<i>x</i> NPs with sizes of 5–10 nm are obtained at a pH value in a range of 9.5–9.8. More interestingly, the obtained NiO<sub><i>x</i></sub> NPs have good dispersion stability and can achieve long-term dispersion in aqueous solution. Furthermore, the structural composition analysis of NiO<sub><i>x</i></sub> NPs shows that the pH value of the synthesis system does not have a significant effect on the material structure nor composition of the NiO<sub><i>x</i></sub> NP. Surface morphological analysis shows that the NiO<sub><i>x</i></sub> film prepared by the pH-controlled NiO<sub><i>x</i></sub> NPs is rather dense and particularly flat with small surface roughness. It is also found that the film exhibits good hole extraction capability. We also fabricate an inverted perovskite solar cell based on the NiO<sub><i>x</i></sub> film. The device structure is ITO/NiO<sub><i>x</i></sub>/CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>/PC61BM/Bphen/Ag. It yields a good photovoltaic conversion efficiency (17.39%). In addition, the device is almost hysteresis-free. Our experimental results exhibit that the performance of perovskite solar cells can be effectively improved by precisely controlling the sizes of NiO<sub><i>x</i></sub> NPs through pH values. Our work is expected to facilitate the development of NiO<sub><i>x</i></sub>-based perovskite solar cells.

Effect of secondary particle size of nickel oxide nanoparticles on cytotoxicity in A549 cells.

The effect of nanoparticle type, shape, as well as primary and secondary particle size on toxicity remains poorly characterized. In this study, suspensions of nickel oxide (NiO) nanoparticles with the same primary particle size (< 50 nm) but different secondary particle sizes were prepared, and their cytotoxicity was investigated. A planetary ball mill wet nanopulverizer with zirconium milling balls of decreasing sizes (φ: 0.5, 0.1, and 0.05 mm) yielded NiO nanoparticles of decreasing mean particle size (310.4 ± 6.7, 172.0 ± 2.8, and 102.0 ± 0.5 nm). Stock solutions were diluted to various concentrations in 10% heat-inactivated fetal bovine serum containing minimum essential medium, and shown to have the same primary particle size, but different secondary particle sizes. Tests with A549 cells revealed that cytotoxicity increased with increasing secondary particle size: milling ball diameter φ 0.05 mm (IC50: 148 μg/mL) < φ 0.1 mm (IC50: 83.5 μg/mL) < φ 0.5 mm (IC50: 33.4 μg/mL). Uptake experiments indicated that the intracellular amount of Ni increased with increasing secondary particle size. In summary, the present findings show that differences in secondary particle size affected the cytotoxicity of NiO suspensions, which could be ascribed at least in part to differences in the amount of NiO taken up by the cells.

Performance of trans perovskite solar cells improved by finely adjusting the particle size of nickel oxide nanoparticles through pH value

As a low-cost, high stable hole transport material, nickel oxide has been widely used in inverted structure perovskite solar cells in recent years. By far, the most common method of preparing nickel oxide hole transport layers is spin-coating pre-prepared nickel oxide nanoparticles (NiO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; NPs), which puts forward high requirement for the particle sizes and solution processing capabilities of NiO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; NPs. In this work, the sizes of NiO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; NPs are precisely controlled by adjusting the pH value of the system in the synthesis process, and high-quality nickel oxide hole transport layers are then prepared. The experimental results exhibit that the NiO&lt;i&gt;&lt;sub&gt;x&lt;/sub&gt;&lt;/i&gt; NPs with sizes of 5–10 nm are obtained at a pH value in a range of 9.5–9.8. More interestingly, the obtained NiO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; NPs have good dispersion stability and can achieve long-term dispersion in aqueous solution. Furthermore, the structural composition analysis of NiO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; NPs shows that the pH value of the synthesis system does not have a significant effect on the material structure nor composition of the NiO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; NP. Surface morphological analysis shows that the NiO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; film prepared by the pH-controlled NiO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; NPs is rather dense and particularly flat with small surface roughness. It is also found that the film exhibits good hole extraction capability. We also fabricate an inverted perovskite solar cell based on the NiO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; film. The device structure is ITO/NiO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;/CH&lt;sub&gt;3&lt;/sub&gt;NH&lt;sub&gt;3&lt;/sub&gt;PbI&lt;sub&gt;3&lt;/sub&gt;/PC&lt;sub&gt;61&lt;/sub&gt;BM/Bphen/Ag. It yields a good photovoltaic conversion efficiency (17.39%). In addition, the device is almost hysteresis-free. Our experimental results exhibit that the performance of perovskite solar cells can be effectively improved by precisely controlling the sizes of NiO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; NPs through pH values. Our work is expected to facilitate the development of NiO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;-based perovskite solar cells.

Structural and Optical Properties of Pure NiO Nanoparticles and NiO-Mn2O3, NiO-CdO, NiO-Pb2O3, NiO-ZnO Nanocomposites

Abstract: Pure nickel oxide (NiO) nanoparticles and NiO-Mn2O3, NiO-CdO, NiO-Pb2O3, NiO –ZnO nanocomposites were synthesized by co-precipitation method. The PXRD studies revealed that NiO, Mn2O3 and CdO possessed cubic structure, Pb2O3 possessed monoclinic structure, ZnO possessed hexagonal structure and confirmed the presence of polycrystallinity nature of NiO and Mn2O3, CdO, Pb2O3, ZnO in the nanocomposites. The average grain size of NiO nanoparticles was found to be 30.10 nm using Debye Scherer’s formula. The FESEM images of NiO nanoparticles and their nanocomposites revealed spherical shaped structure and NiO-Pb2O3 revealed needle shaped rod-like structure. EDAX analysis confirmed the composition of NiO nanoparticles and their nanocomposites. Raman spectra exhibited characteristic peaks of pure NiO and that of NiO- Mn2O3, NiO-CdO, NiO- Pb2O3, NiO-ZnO in the synthesized nanocomposites. In the PL spectra, blue and green emission was observed in the samples. UV-vis spectra revealed the absorption peaks of NiO nanoparticles and their nanocomposites. Thus, the synthesized NiO- Mn2O3, NiO-CdO, NiO - Pb2O3 and NiO-ZnO nanocomposites can be a suitable material for electrocatalysis applications. Keywords: Nickel oxide nanocomposites, Structure, Morphology, Absorption, Luminescence.

Amine mediated synthesis of nickel oxide nanoparticles and their superior electrochemical sensing performance for glucose detection

Nickel based materials with nanoscale is great attention in various electrochemical application owing to their good redox characteristics, easy preparation, low cost and less toxic in nature. In the present work, simple and ultra-small size of nickel oxide nanoparticles (NiO NPs) was prepared by simple calcination of nickel and p-Phenylene diammine complex. The synthesized NiO NPs were studied by FE-SEM, XRD, and cyclic voltammetry. The NiO NPs modified glassy carbon electrode (GCE) demonstrated good electro-catalytic performance for glucose oxidation with higher oxidation peak current (ipa :46.9 ± 0.2 µA) when correlated to that of bulk NiO (ipa : 10.3 ± 0.3 µA) and unmodified GCE (ipa: 1.7 ± 0.3 µA) electrodes. Further, the NiO NPs coated electrode surface exhibited good linear range (5 µM–2.49 mM), high sensitivity (0.310 µA µM−1 cm−2), low detection limit (3.5 µM), good response time (<f5 s), selectivity, and stability. The optimized work was successfully utilized for accurate determination of glucose in blood serum sample.

Photocatalytic and biomedical investigation of green synthesized NiONPs: Toxicities and degradation pathways of Congo red dye

In this study the biomedical and catalytic ability of green synthesized nickel Oxide nanoparticles (NiONPs) was investigated. The extract of medicinal plant Tribulus terrestris were used to synthesized NiONPs. The as-synthesized NiONPs were in nano scale and were characterized with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), High-Resolution Transmission Electron Microscopy (HRTEM), Scanning Electron Microscope (SEM), X-ray photoelectron spectroscopy (XPS) and Energy Dispersive X-ray spectroscopy (EDX). The synthesis of NiONPs was ensured with surface Plasmon resonance (SPR) at 425 nm and the strong EDX. The effect of different concentrations of plant extract on the size of NiONPs was evaluated. The HRTEM results showed particle size between 60 - 90 nm. The study showed that lesser the extract concentration, more spherical and small sized particles were obtained without aggregation. The biological applications of NiONPs were evaluated against different fungal species like Asper gillusflavus, Asper gillusfumigatus, Asper gillusniger and standard medicine Terbinafine. A. niger, A. flavus and A. fumigatus exhibited 57, 63 and 52 % inhibition compared with inhibition of the reference medicine which is 98, 100 and 100%. NiONPs have been shown to be more effective against gram-positive bacteria than gram-negative bacteria like E. Coli 9(±0.7) and S. aureus13 (±0.8). Moreover, antioxidant properties of the as-synthesized NiONPs were evaluated with 2, 2 diphenyl-1-picrylhydrazyl) (DPPH). The catalytic ability of green synthesized of NiONP was investigated for the degradation of Congo red dye (CR) as a hazardous environmentally contaminations in water. The biosynthesized NiONPs were found to be active catalytic for the degradation toxic dyes like CR. the catalytic activity of NiONPs can be explained by its small size compared with balk material. Mechanisms for CR degradation have been proposed. The Ecotoxicity of CR and components derived from dye was investigated with Ecological Structure Activity Relationship (ECOSAR) program.

Effect of “Magnetized Water” on Size of Nickel Oxide Nanoparticles and their Catalytic Properties in Co2 Reforming of Methane

It was shown that the particle size of NiO nanoparticles has been controlled through the homogeneous precipitation process by using “magnetized water” which, according to the authors, is due to a change in the surface tension and viscosity of water under the influence of a magnetic field. The textural properties, shape, recovery behavior, and size distribution of NiO nanoparticles were determined using BET, XRD, TPR, and TEM methods. The effect of NiO particle size on the catalytic reaction of carbon dioxide reforming of methane into synthesis gas was studied. The CO2 and CH4 conversions and the yield of CO and H2 products possess higher values for the treated NiO sample.

Newly synthesized salicylidene-4,4′-dimorpholine (SDM) assembled on nickel oxide nanoparticles (NiONPs) and its inhibitive effect on mild steel in 2 N hydrochloric acid

Corrosion inhibition of mild steel in hydrochloric acid solution by salicylidene-4,4′-dimorpholine (SDM) and SDM assembled on nickel oxide nanoparticles (NiONPs) has been studied with gravimetric, electrochemical impedance spectroscopy (EIS) and polarization techniques. Inhibition was found to increase with increasing concentration of the inhibitors. While studying the temperature effect on corrosion behaviour of SDM and SDM assembled on NiONPs, the inhibition efficiency decreases for SDM only but increases for SDM assembled on NiONPs. The adsorption of both the inhibitors on the mild steel surface obeys the Langmuir adsorption isotherm. The activation energy as well as other thermodynamic parameters (ΔH* and ΔS*) for the inhibition process was calculated. EIS analysis results showed that the capacitive loops for SDM assembled on NiONPs were far away from blank when compared with SDM only. Polarization curve shows that the inhibitors are of mixed type. Further, the protective layer formation was confirmed from atomic force microscopy (AFM) results. Various methods such as EIS-MS, 1H NMR, XRD, FTIR, and DLS were performed for the confirmation of the structure, interaction of SDM with NiONPs and size of NiONPs.

NiO/nanoporous graphene composites with excellent supercapacitive performance produced by atomic layer deposition

Nickel oxide (NiO) is a promising electrode material for supercapacitors because of its low cost and high theoretical specific capacitance of 2573 F g−1. However, the low electronic conductivity and poor cycling stability of NiO limit its practical applications. To overcome these limitations, an efficient atomic layer deposition (ALD) method is demonstrated here for the fabrication of NiO/nanoporous graphene (NG) composites as electrode materials for supercapacitors. ALD allows uniform deposition of NiO nanoparticles with controlled sizes on the surface of NG, thus offering a novel route to design NiO/NG composites for supercapacitor applications with high surface areas and greatly improved electrical conductivity and cycle stability. Electrochemical measurements reveal that the NiO/NG composites obtained by ALD exhibited excellent specific capacitance of up to ∼1005.8 F g−1 per mass of the composite electrode (the specific capacitance value is up to ∼1897.1 F g−1 based on the active mass of NiO), and stable performance after 1500 cycles. Furthermore, electrochemical performance of the NiO/NG composites is found to strongly depend on the size of NiO nanoparticles.

Optical diagnostics of physicochemical properties of NiO/Al2O3 nanocomposites upon exposure to different gases and heat

We have studied nanostructural and optical properties of composites of nanostructured nickel oxide films on a substrate from porous aluminum oxide NiO/Al2O3 in the UV, visible, and IR spectral ranges on exposure of composites to different gases, vacuum, and heat. We have found that, upon irradiation of NiO/Al2O3 composites by laser radiation at a wavelength of 633 nm, they demonstrate a high sensitivity to carbon monoxide CO in the range of the excitonic absorption of nickel oxide. We assume that an increase in the transmission coefficient of the composite in the excitonic absorption band is determined by luminescence that is caused by the oxidation reaction of carbon monoxide. The sensitivity of composites to CO is enhanced with decreasing the size of NiO nanoparticles and after evacuation. The values of the diffuse reflection coefficient at the laser radiation wavelength of 633 nm correlate with the size of nickel oxide nanoparticles. Spectral changes in the range of the fundamental absorption band of NiO that occur in the IR range and in diffuse reflection spectra are related to the appearance of carbon-containing compounds in the composite exposed to CO.