Synthesized NiO NPs Research Articles

Salvia officinalis leaf extract-stabilized NiO NPs, ZnO NPs, and NiO@ZnO nanocomposite: Green hydrothermal synthesis, characterization and supercapacitor application

AbstractIn this study, NiO nanoparticles (NiO NPs) and NiO@ZnO nanocomposite were synthesized for the first time using a Salvia officinalis (S. officinalis) extract-assisted hydrothermal process. The S. officinalis leaf extract served as a natural reducing and capping agent. The synthesized NiO NPs, ZnO NPs, and NiO@ZnO nanocomposite were thoroughly characterized using various techniques, including Fourier-transform infrared spectroscopy (FT-IR), ultraviolet–visible spectroscopy (UV–Vis), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), energy-dispersive spectrometry (EDS) mapping, vibrating sample magnetometer (VSM), and cyclic voltammetry (CV) analysis. The direct and indirect band gap energies of NiO NPs, ZnO NPs, and NiO@ZnO were found to be 3.00, 2.28, and 2.71 eV, and 2.63, 1.91, and 2.23 eV, respectively. The crystallite sizes were analyzed using PXRD spectra through Scherrer and Williamson–Hall (W–H) methods. TEM analysis revealed that the average particle sizes of NiO NPs, ZnO NPs, and NiO@ZnO were 16.0, 207.5, and 31.0 nm, respectively. The magnetic properties of all nanomaterials were assessed via the VSM technique. Specific capacitance (Cs) values, determined from CV voltammograms, were 196.8, 632.4, and 785 Fg-1 at a scan rate of 25 mVs-1 for NiO NPs, ZnO NPs, and NiO@ZnO, respectively. These findings suggest that the green-synthesized NiO@ZnO nanocomposite holds significant potential as a high-performance electrode material for supercapacitor applications.

Ameliorating and tuning the optical, dielectric, and electrical properties of hybrid conducting polymers/metal oxide nanocomposite for optoelectronic applications

Quaternary nanocomposite films with favorable electrical and optical properties have been produced by adding nickel oxide nanoparticles (NiO NPs) to polyvinyl alcohol (PVA), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), and polypyrrole (PPy) with a solution casting technique. In this study, different concentrations of NiO NPs were added to pure PVA/PEDOT:PSS/PPy blends and investigated through various characterization methods. From transmission electron microscopy (TEM) and X-ray diffraction (XRD) observations, the synthesized NiO NPs have a cubic phase and a diameter that varies between 6 and 40 nm. XRD analysis also indicates that the filling of PVA/PEDOT:PSS/PPy with NiO NPs results in a decrease in the crystallinity of the nanocomposites prepared. Raman analysis demonstrated the existence of prominent distinctive peaks associated with vibrational groups that characterize the synthesized samples, which change randomly with increasing concentrations of NiO NPs. In the UV/VIS spectrum for the PVA/PEDOT:PSS/PPy blend, there were two absorbance peaks at 202 and 224 nm that may result from π→π* and n→π* transitions. The results show that, by increasing NiO NP concentrations, UV/Vis absorbance increased by about 44 % at wavelength ranges from 190 to 240 nm, while optical band gap energies for indirect transitions decreased from 4.96 to 4.85 eV. The AC electrical conductivity of the films has been investigated via impedance spectroscopy at frequencies from 10−1 to 107 Hz. As the NiO NPs concentration in the blend rises, the AC electrical conductivity increases and is shown to follow Jonscher's rule. Additionally, it has been demonstrated that nanoparticle concentration causes a rise in composite dielectric loss and dielectric constant. The reduction in the optical bandgap energies and the enhancement of electrical properties due to the filling with NiO NPs suggest the possibility of using the prepared nanocomposites in optoelectronic devices.

The biosynthesis of nickel oxide nanoparticles using watermelon rind extract and their biophysical effects on the germination of Vigna radiata seeds at various concentrations

Unique and bio-inspired synthesis of nickel oxide nanoparticles by using an innocuous and ecofriendly waste material that is watermelon rind. In the reaction, watermelon rind recycled and used its extract as a solvent which act as a reductant for a synthesis of nickel oxide nanoparticle. The synthesized NiO NPs were analyzed by using X-ray Diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and UV-Vis spectroscopy. FTIR peak at 745 cm-1 and 671 cm-1 indicated that the formation of Ni-O bond. A prominent peak of UV-Vis spectra at 283 nm and band gap, calculated with the help of UV data, was ~3.3 eV. The obtained PXRD pattern and JCPDS data suggested the formation of nickel oxide nanoparticle and the average crystallite size calculated by Scherrer’s equation in between 30 to 150 nm. The average grain size of NiO NPs perceived from TEM images was 46.55 nm and polygonal barrel shape particles. Since, a simple, straightforward, pollutant-free, and economical technique for the synthesis of nickel oxide nanoparticles. However, the above synthesized nickel oxide nanoparticles have been explored for biophysical parameter vis. radicle length, plumule length and germination percentage on a Vigna radiata (moong) seed by the treatment of some concentration i.e. 25 ppm, 50 ppm, 100 ppm and 200 ppm in germination processes. At a low concentration of 25 ppm, a beneficial improvement in the germination process of Vigna radiata seed was observed.

In-vitro cytotoxicity of nickel oxide nanoparticles against L-6 cell-lines: MMP, MTT and ROS studies

In the present work we synthesize nickel oxide nanoparticles (NiO NPs) using Rhododendron arboretum (flower) (RNi), Tinospora cordifolia (stems) (GNi), Corylus jacquemontii (seeds) (CNi), and Nardostachys jatamansi (roots) (NNi) extracts by co-precipitation method. The synthesized NiO NPs were characterized in detail in terms of their morphological, crystalline nature, structural and antiproliferative activity against rat skeletal myoblast (L-6) cell lines. Morphological studies confirmed the formation of nanoparticles, while the structural and compositional characterization revealed the well-crystallinity and high purity of the synthesized nanoparticles. For biological applications and cytotoxicity examinations of the synthesized NPs, the rat skeletal myoblast (L-6) cell lines were subjected to study. By detailed cytotoxic investigations, it was observed that among the four kinds of NiO NPs prepared through different plant extracts, the Tinospora cordifolia (stems) showed strong antiproliferative activity against rat skeletal myoblast (L-6) cell lines and the calculated IC50 was 1.671 mg/mL. The observed antiproliferative activity towards different NiO NPs were in the order of GNi > NNi > RNi > CNi. The present studies demonstrate that simply synthesized NiO can efficiently be used as antiproliferative agents.

Microwave and combustion methods: a comparative study of synthesis, characterization, and applications of NiO nanoparticles

Synthesis of NiO NPs was achieved using microwave (MW) and solution combustion (SC) method, with the help of tender jackfruit extract as a green fuel. The efficiency of the two methods was compared by focusing on some of the important parameters like particle size, structure, optical property, photodegradation, supercapacitor, and sensing activity. Treatment of Nickel(II) nitrate hexahydrate solution with jackfruit extract, stable NiO NPs were obtained. Further, the characterization part involves PXRD, FTIR, UV, SEM, EDS analysis. PXRD patterns illustrate the FCC structure for NiO NPs for both methods and the crystallite size was obtained to be 3.9 nm and 3.8 nm. The FTIR spectra indicate the Ni-O stretching vibrations of synthesized NiO NPs. UV–Vis spectra shows the absorbance at 324 nm and 271 nm by SC and MW method, respectively. The bandgap energy of the MW method (2.3 eV) was more as compared to the combustion method (2.55 eV). Results of photodegradation experiments showed that MW synthesized NiO NPs were more effective as compared to SC synthesized NiO NPs against Rhodamine-B dye. Finally, impedance plots exhibit the supercapacitor activity and also NiO NPs showed excellent sensing activities.

NiO nanoparticles with superior sonophotocatalytic performance in organic pollutant degradation

Herein, NiO nanoparticles were prepared by a facile solvothermal route. The as-synthesized nanoparticles were characterized using XRD, BET, TEM, HRTEM. The BET measurements prove the mesoporous nature of the NPs, having good specific surface area and pore volume. The synthesized NiO NPs were used for the first time in dye decomposition using methylene blue (MB) as a model pollutant in low frequency and low energy ultrasound at pH = 7 and room temperature in presence of UV light and H2O2 as an oxidant. The change of the pollutant concentration was estimated by UV–VIS spectrophotometry. Dye degradation performance investigated for sonocatalysis, photocatalysis, and sonophotocatalysis processes. The data showed that the decomposition performance was in the following order: sonophotocatalysis>photocatalysis>sonocatalysis. After about 30 min of dual (Sono + UV) irradiation in the presence of NiO NPs more than 90% of the pollutant degraded, achieving a rate constant of about 0.089 min−1. Sonophotocatalytic performance was compared with sonocatalysis and photocatalysis processes carried out in the same conditions. Interestingly, the combination of ultrasound and UV light irradiation in a sonophotocatalytic degradation process led to about 33% synergy effect, proving a positive synergy between the sonocatalytic and photocatalytic processes. Reusability data exhibited the excellent stability of sonophotocatalysts within four consecutive runs with negligible fading in their sonophotocatalytic performance. This feature improves the reusability potential of the sonophotocatalysts to be applied in the industrial directions. The obtained results proved that the performance of the sonophotocatalytic process was severely affected by the addition of different kinds of trapping agents, therefore based on these results the mechanism of the sonophotocatalysis was discussed. Finally, the presently combined system paved the way toward excellent efficiency and it could pose a good strategy, in terms of environmental impact and energy cost, in comparison to conventional sonophotocatalytic systems.

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.

Biogenic Synthesis of NiO Nanoparticles Using Areca catechu Leaf Extract and Their Antidiabetic and Cytotoxic Effects.

Nanoworld is an attractive sphere with the potential to explore novel nanomaterials with valuable applications in medicinal science. Herein, we report an efficient and ecofriendly approach for the synthesis of Nickel oxide nanoparticles (NiO NPs) via a solution combustion method using Areca catechu leaf extract. As-prepared NiO NPs were characterized using various analytical tools such as powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-Visible spectroscopy (UV-Vis). XRD analysis illustrates that synthesized NiO NPs are hexagonal structured crystallites with an average size of 5.46 nm and a hexagonal-shaped morphology with slight agglomeration. The morphology, size, and shape of the obtained material was further confirmed using SEM and TEM analysis. In addition, as-prepared NiO NPs have shown potential antidiabetic and anticancer properties. Our results suggest that the inhibition of α-amylase enzyme with IC 50 value 268.13 µg/mL may be one of the feasible ways through which the NiO NPs exert their hypoglycemic effect. Furthermore, cytotoxic activity performed using NiO NPs exhibited against human lung cancer cell line (A549) proved that the prepared NiO NPs have significant anticancer activity with 93.349 μg/mL at 50% inhibition concentration. The biological assay results revealed that NiO NPs exhibited significant cytotoxicity against human lung cancer cell line (A549) in a dose-dependent manner from 0–100 μg/mL, showing considerable cell viability. Further, the systematic approach deliberates the NiO NPs as a function of phenolic extracts of A. catechu with vast potential for many biological and biomedical applications.

Evaluation of the Biological Activity of Nickel Oxide Nanoparticles as Antibacterial and Anticancer Agents

In the present study, nickel oxide nanoparticles (NiO NPs) were evaluated as an antibacterial and anticancer agent. The nanoparticles of nikel oxide were synthesized using aloe vera leaves extract and characterized with AFM (showing an average diameter of 45.11 nm), XRD and FE-SEM analyses. Three different concentrations (125, 250 and 500 µg/ml) were prepared from the synthesized NiO NPs and investigated for their potential antibacterial activity against both Enterococcus faecalis (Gram-positive bacteria) and Acinobacter baumannii (Gram-negative bacteria). While cytotoxicity and apoptotic activity were measured on both MCF-7 and AMJ13 cancer cell lines by MTT and caspase-9 luminescence assays. The results showed that NiO NPs inhibit bacterial growth, as indicated by large inhibition zones against both tested bacteria, with all studied concentrations. Moreover, the results of cytotoxicity and caspase-9 activity assays were in concordance with those of antibacterial activity, showing high cytotoxicity and apoptotic effects against both of the studied cancer cell lines and with all the tested concentrations of NiO NPs. Both the antibacterial and anticancer activities of NiO NPs were dose-dependent.

Photocatalytic, nitrite sensing and antibacterial studies of facile bio-synthesized nickel oxide nanoparticles

In the present work, Nickel oxide nanoparticles (NiO NPs) were synthesized using leaves extract of C. gigantea through a solution combustion method. The NiO NPs were characterized through analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). The XRD results revealed rhombohedral structured crystallites with average size of 31 nm. SEM and TEM images indicate that the nanoparticles are agglomerated with an asymmetrical shape. The optical energy bandgap of 3.45 eV was estimated using UV-diffused reflectance spectroscopy (UV-DRS). The synthesized NiO NPs have shown superior photodegradation for methylene blue (MB) dye. Further, the antibacterial activity of the prepared nanoparticles was tested against E.coli and S.aureus bacterial strains. In addition, nanoparticles were utilized for electroanalytical applicability as a novel non-enzymatic sensor in the trace level quantification of nitrite. The proposed nitrite sensor showed wide linearity in the range 8–1700 μM and good stability with a lower detection limit of 1.2 μM. • Nickel oxide nanoparticles (NiO NPs) were synthesized using Calotropis gigantea through solution combustion method. • The prepared NPs were characterized using FT-IR, XRD, SEM, EDAX, HR-TEM and voltammetric techniques. • The NiO NPs showed good performance in degradation of MB dye and better antibacterial activity against E . coli and S . aureus bacterial strains. • The NiO NPs modified electrode showed the excellent electro catalytic behavior in the electrochemical sensing of nitrite with detection limit of 1.2 μM.

Biosynthesis of Nickel oxide Nanoparticles from Euphorbia heterophylla (L.) and their biological application

Nickel oxide Nanoparticles (NiO NPs) were synthesized from E. heterophylla (L.) leaves extract act as reducing/capping agent by biosynthesis process. Further the synthesized NiO NPs was subjected for structural, optical and biological properties. The XRD pattern of NiO NPS exhibit face centred cubic (FCC) crystalline structure. The UV-DR spectrum of biosynthesized NiO NPs exhibited optical properties with well-defined at 321 nm and its exhibits optical band gap is 3.24 eV. The FT-IR spectrum of NiO NPs shows stretching vibration of Ni-O at 452 cm−1. The morphological features of NiO NPs are rhombohedra and slightly agglomerated and then size of the biosynthesized NiO NPs as found in the range of 12–15 nm. The NiO NPs shows vital non-toxic properties on human erythrocytes and its interference in activity coagulation cascade both on PRP and PPP on human blood. The Bactericidal activity of NiO NPs was shows significant inhibitory activity against pathogenic bacterial strains. Further, NiO NPs show significant cytotoxicity against human lung cancer cell line (A549) and human hepatocarcinoma (HepG2) cell lines. Therefore, the study reveals states that, the E. heterophylla (L.) leaves extract is an effective reducing/capping agent for the formation of NiO NPs and its exhibits biological properties.

Sunlight mediated photocatalytic degradation of organic pollutants by statistical optimization of green synthesized NiO NPs as catalyst

In this manuscript we have prepared nickel oxide nanoparticles (NiO NPs) using Calotropis gigantea latex (CGL) through green synthesis method in which the latex acts as a capping agent. The synthesis part was optimized using RSM-BBD methodology. Further the synthesized NiO NPs were subjected to various analytical techniques like UV–Visible spectroscopy, Transmission Electron Microscope (TEM), X-ray diffractometer (XRD), Energy Dispersive Analysis (EDX), Particle Size Histogram and Zeta potential. We observed the cuboidal shape of NiO NPs with 28 ± 2 nm as average particle size. Further the synthesized NiO NPs were subjected to degrade toxic diazo dye Congo red (CR) and organic compound 4-Nitro phenol in the presence of sunlight within short duration of time. The results indicate that the NiO NPs degrades 95% of CR and 94% of nitro phenol.

Eco-Friendly Biosynthesis of Nickel Oxide Nanoparticles Mediated by Okra Plant Extract and Investigation of Their Photocatalytic, Magnetic, Cytotoxicity, and Antibacterial Properties

In the present stud, NiO–NPs have been synthesized via the sol–gel method and using okra plant extract as a reducing and limiting agent. The optical, photocatalytic, structural and magnetic properties of the NiO–NPs have been investigated via the usage of FTIR, UV–Vis, XRD, FESEM, EDX, VSM, and TGA/DTA. The results of the achieved XRD and FT-IR analyses have confirmed the formation of pure and crystalline NiO–NPs. The thermal behavior of the composition has been studied by the utilization of TGA/DTA results. Moreover, the synthesized NiO–NPs have illustrated a super-paramagnetic behavior throughout the performance of magnetic studies by the means of VSM procedure. Cell cytotoxicity investigation has been carried put on multiple tumor cells by the MTT method, while the antimicrobial studies have displayed that NiO–NPs activity for gram-positive bacteria species seems to be more apparent than the gram-negative bacteria species. Photocatalytic degradation researches have confirmed the consistency of its effects with complete degradation of MB in pH = 11, under optimal conditions. Therefore, we propose a green protocol for the combination of effective biological agents with high purity and crystallinity along with reduced particle size, which stands as beneficial factors to be employed in a variety of applications and environments.

Use of plant based analytes for the synthesis of NiO nanoparticles in catalyzing electrochemical H2O2 production

This work demonstrates that the use of plant based analytes for the synthesis of weak ferromagnetic microporous (75% pores within 1.52 to 2 nm) NiO nanoparticles (NPs, mean 12.11–14.48 nm). This process is inexpensive and simple and, uses the extracted analytes from Sechium edule which is rich in ascorbic acid (AA).The characterizations of NiO NPs were performed for its structural, functional, thermal, and morphological attributes. Ni(OH)2 was formed at a higher pH by the ligand exchange between AA− and OH− which was completely converted to NiO NPs after the calcination (500 °C for 2 h) as supported by the mass spectra of analytes and control-experiment. The synthesized NiO NPs were immobilized on the graphite surface and tested for its electrocatalytic activity for the production of H2O2 in an acidic pH (1.5 ≤ pH ≤ 4.5, 0.5 M Na2SO4 and O2 flow rate 1.0 LPM). From the cyclic voltammetric tests (vs. Ag/AgCl), it was found that O2 reduction took place at a low overpotential (0.125 V) which was independent on the solution pH, but the cell current was diminishing beyond the optimal pH of 2.5.There was a remarkable increase in the cell current (3.5 times) and current efficiency (61% higher) of H2O2 formation with graphite/NiO NPs cathode than the bare graphite and, the current efficiency didn't decrease (5–7%) much during electrolysis. The limiting current density (1.42 A/m2) was independent on the surface area of graphite/NiO NPs cathodes and, the mass transfer coefficient (km) and thickness (δ) of O2 diffusion layer were 0.955 × 10−5 m/s and 209 μm, respectively.

Preparation and Exploration on the Electrochemical Behavior of Nickel Oxide Nanoparticles Coated Bacterial Nanowires

The controlled synthesis of nickel oxide nanoparticle (NiO NPs) were synthesized by homogeneous precipitation method and have been characterized using UV–visible spectrophotometer, fourier transform-infrared spectroscopy, X-ray diffraction, atomic force microscope, scanning electron microscope and high resolution-transmission electron microscope. The synthesized NiO NPs was spherical in shape with an average size ranged between 3 and 5 nm. Subsequently, synthesis of NiO NPs coated on a bacterial nanowires (BNWs) film pre-cast on a glassy carbon electrode surface and the morphology and nature of the prepared composite was characterized using HR-TEM. The electro-chemical behavior of NiO NPs coated bacterial nanowires (NiO NPs-BNWs) was observed using cyclic voltammetry, linear sweep voltammetry and electrochemical impedance spectroscopy analysis. Highly comparable electrochemical conductivity of NiO NPs-BNWs was observed in this study. The BNWs sample exhibited a polarization resistance (Rp) to be 4457 Ω and the NiO NPs-BNWs sample exhibited polarization resistance (Rp) about 2270.4 Ω. The BNWs exhibited a CPE-T value to be 6.26 µF cm−2 and the NiO NPs-BNWs sample exhibited CPE-T to be 9.32 µF cm−2. The enhancement of peak currents is ascribed to the short heterogeneous electron transfer among the NiO NPs-BNWs. The defined nanolayer provides a novel platform for the next generation electrochemical applications.

Neem leaves mediated preparation of NiO nanoparticles and its magnetization, coercivity and antibacterial analysis

Nickel oxides nanoparticles (NiO NPs) were synthesized by biosynthesis method with the help of phytoconstituents present in the neem leaf. Further the synthesized NiO NPs were subjected for structural, optical, morphological and magnetic properties. The XRD patterns clearly infer the presence of polycrystalline nature of samples (010), (011) and (012) with hexagonal crystal phase. Morphological studies using Transmission Electron Microscope (TEM) reveals that the biosynthesized NiO NPs were in shape of oblong with 12nm in size. Elemental analysis (EDAX) confirms the quantity of Ni is present at 51% and remaining O as 49% as well as the mass magnetization values of 61emu/g are also recorded for NiO NPs and its coercivity values in the range of 0.2–0.4 of nanoparticles respectively. Finally the NiO NPs was studied for bacterial activity against Staphylococcus aureus (MTCC 1430) and followed by Escherichia coli (MTCC 739) by agar diffusion assay.