Ni Doped ZnO Nanoparticles Research Articles

Ni-doped ZnO nanoparticles derived by the sol–gel method: structural, optical, and magnetic characteristics

A simple sol–gel route was used for preparation of Ni doped ZnO nanoparticles (Ni:ZnO) with 0, 3, 5, 7 and 9 wt% of Ni to Zn precursor salts. Structural, optical and room temperature magnetic properties were studied. The prevailing structural arrangement that observed in all the examined samples is the wurtzite structure of ZnO. Nevertheless. The orderly development of NiO rock-salt phase on at the surfaces of ZnO nanoparticles upon Ni doping is confirmed by Rietveld refinements. The ZnO wurtzite structure is dominant in all the samples as confirmed by both XRD and Raman results. The average crystallite size showed almost no change upon Ni doping. RTFM behavior is being exhibited for all Ni:ZnO nanoparticles that is demonstrating using of ZnO as the host structure allowed for the efficient formation of DMS. The Near-infrared solar reflectance (RNIR) and the visible solar reflectance (RVis) values reduced with increasing of the Ni content as a result of the rising in density of trap states upon Ni doping of the samples. Kubelka-Munk method was used to determine the energy band gap (Eg) and band Urbach energy (EU) tails from diffused reflectance (DRS) results. The obtained energy gap values were very close in all studied samples with an average value of energy gap is 3.164 eV. The EU values raise from 123 to 173 meV upon increasing of Ni content in the samples in agreement with lower values of RNIR and RVis and their effect on optical performance of the investigated samples in applications.

Efficient Production of Biodiesel by the Transesterification of Neem Oil Using Ni-Doped ZnO Nanoparticles as Heterogeneous Catalysts

Efficient Production of Biodiesel by the Transesterification of Neem Oil Using Ni-Doped ZnO Nanoparticles as Heterogeneous Catalysts

Nickel doped ZnO nanoparticles as a novel photocatalytic and multiferroic semiconductor

Structural analysis, spectroscopic studies and multiferroic properties of Zn1-xNixO (x = 0, 0.03, 0.06, 0.09, 0.12, 0.15) nanoparticles are reported here. Ni-doped ZnO nanoparticles were synthesized through a simple chemical growth route using hydroxyoxalate type materials. The hexagonal wurtzite structure of prepared compounds has been ascertained through X-ray diffraction. High Resolution Transmission Electron Microscopy (HRTEM) reveals the particle size and lattice growth direction of the nanoparticles. The expected doping concentration of nickel was confirmed by Energy Dispersive X-ray (EDX) spectroscopy. The excitonic peaks observed from absorption spectra of the prepared nanoparticles exhibit blue shift for nickel doping. Ni-doped ZnO explore superior photocatalytic response and are controlled by three factors: band gap, crystallite size and surface defect. To be specific, 12 % Ni doping results in 7.8 times increase in the photocatalytic degradation efficiency. The samples exhibit characteristic P-E and M − H loops. The obtained remnant polarization for 9 % and 15 % Ni doping are 9 × 10−3 and 6 × 10−3 μC/cm2 respectively. The multiferroicity perceived in the synthesized Ni-doped ZnO nanoparticles with the ME coefficient at around 1.1mV/cm-Oe have important application potentiality in electromagnetic coupled devices.

Multifaceted investigations of co-precipitated Ni-doped ZnO nanoparticles: Systematic study on structural integrity, optical interplay and photocatalytic performances

The present study demonstrates the successful synthesis of ZnO and nickel doped ZnO NPs by co-precipitation method. XRD analysis, confirms hexagonal wurtzite structure. The crystallite size increased from 31 to 45 nm with increasing Ni ions and a reduction in the unit cell volume, owing to the smaller ionic radius of Ni2+ compared to Zn2+. PL spectra were observed for pristine ZnO, associated with near band edge emission band, arising from the recombination of free excitons. Due to the splitting of orbitals caused by the presence of magnetic ions, the optical bandgap is found to be decreasing whereas an increase in the occupancy of 3d electrons. The absorption band observed corresponds to the stretching mode below 450 cm−1. A distinctive peak at around 436 cm−1 was identified in the Raman spectra, indicating the high-frequency branch E2 mode in ZnO. Ni-doped (Zn0·91Ni0·09O) NPs achieve about 80 % photodegradation of MEG dye.

Highly Effective Photocatalytic Performance in Visible Light of Sodium hexametaphosphate Capped Ni-Doped ZnO Nanoparticles

This study describes the microwave assisted synthesis of without and with sodium hexametaphosphate (SHMP) (1 mol%) capped 3 mol% Ni- doped ZnO nanoparticles. Various sophisticated analytical techniques were used to characterize the Ni-doped ZnO nanoparticles. The results showed that including SHMP capped 3 mol% Ni-doped ZnO nanoparticles has a significant influence on the photoctalyst and structural characteristics of the ZnO nanoparticles. Under visible light illumination, SHMP capped 3 mol% Ni-doped ZnO nanoparticles demonstrated better photocatalytic degradation of methylene blue dye. As a result, SHMP capped 3 mol% Ni-doped ZnO nanoparticles synthesized are suitable materials for the environmental applications.

Facile Synthesis of Ni-Doped ZnO Nanoparticles Using Cashew Gum: Investigation of the Structural, Optical, and Photocatalytic Properties

This work adopted a green synthesis route using cashew tree gum as a mediating agent to obtain Ni-doped ZnO nanoparticles through the sol–gel method. Structural analysis confirmed the formation of the hexagonal wurtzite phase and distortions in the crystal lattice due to the inclusion of Ni cations, which increased the average crystallite size from 61.9 nm to 81.6 nm. These distortions resulted in the growth of point defects in the structure, which influenced the samples’ optical properties, causing slight reductions in the band gaps and significant increases in the Urbach energy. The fitting of the photoluminescence spectra confirmed an increase in the concentration of zinc vacancy defects (VZn) and monovacancies (Vo) as Zn cations were replaced by Ni cations in the ZnO structure. The percentage of VZn defects for the pure compound was 11%, increasing to 40% and 47% for the samples doped with 1% and 3% of Ni cations, respectively. In contrast, the highest percentage of VO defects is recorded for the material with the lowest Ni ions concentration, comprising about 60%. The influence of dopant concentration was also reflected in the photocatalytic performance. Among the samples tested, the Zn0.99Ni0.01O compound presented the best result in MB degradation, reaching an efficiency of 98.4%. Thus, the recovered material underwent reuse tests, revealing an efficiency of 98.2% in dye degradation, confirming the stability of the photocatalyst. Furthermore, the use of different inhibitors indicated that •OH radicals are the main ones involved in removing the pollutant. This work is valuable because it presents an ecological synthesis using cashew gum, a natural polysaccharide that has been little explored in the literature.

Synthesis and Characterization of Ni Doped ZnO Nanoparticles and Study of their Antibacterial Activity

Synthesis and Characterization of Ni Doped ZnO Nanoparticles and Study of their Antibacterial Activity

Photocatalytic degradation of amoxicillin using TM doped ZnO nanoparticles synthesized from orange peel extract

The present work investigates the degradation of Amoxicillin using ZnO and Fe, Ni, Co doped ZnO nanoparticles synthesized using orange peel extract. The synthesized catalysts were characterised with the help of X-ray diffraction, scanning electron microscopy, UV–Visible and photoluminescence spectroscopy for structural and optical properties and the study of charge transport behaviour of the catalysts. The observed results indicate that the Ni doped ZnO nanoparticles exhibit superior degradation efficiencies of 80.71% and 86.21% under UV light and UV + visible light irradiation. Moreover, the slightly basic environment was found to be favourable for optimizing the degradation efficiency of the catalyst, as confirmed by the pH variation experiment. The scavenging experiments were utilized to reveal the most prominent role of hydroxyl radicals in the degradation of Amoxicillin. Additionally, a mere 10.97% reduction in degradation efficiency was observed after fours cycles of degradation experiment. The plausible pathway of amoxicillin degradation has been included into this study as well. Hence, the transition metal (TM) doped ZnO nanoparticles synthesized through waste orange peels suggest their utilization as efficient photo catalyst in Amoxicillin degradation.

Exploring the structural, optical, and magnetic properties of Ni-doped ZnO nanoparticles synthesized via microwave irradiation

Nickel-doped zinc-oxide nanoparticles are synthesized by the solvothermal method at different doping concentrations (x = 0.02, 0.04, 0.06, and 0.08). The structural properties of undoped and nickel-doped zinc oxide nanoparticles are carried out. X-ray diffraction analysis confirms the hexagonal wurtzite structure (belonging to the space group p63mc) and optical properties are analyzed through UV–visible, Fourier-transformed infrared, and hotoluminescence. Energy bandgap values are found using the Tauc plot method. The Lande splitting factor is calculated using EPR analysis. Magnetic properties of the sample are measured using a vibrating sample magnetometer at room temperature. It is observed that their behavior changes from paramagnetic to superparamagnetic structure with an increase in their doping values. In the large saturation magnetization, it is very suitable for magnetic storage device applications.

Bio-fabrication of Ni doped ZnO nanoparticles using Annona Muricata leaf extract and investigations of their antimicrobial, antioxidant and photocatalytic activities

The present work aims to investigate the structural, optical, antimicrobial, antioxidant and photocatalytic activities of Zn1−xNixO (x = 0, 0.03, 0.05 & 0.07) nanoparticles prepared by the green method using Annona Muricata leaf extract. The synthesised nanoparticles were analysed by XRD, FTIR, XPS, HRTEM- SAED, SEM- EDX and UV-Visible spectroscopy. The XRD pattern confirms Ni has been successfully incorporated into the hexagonal wurtzite structure of ZnO. XPS results demonstrate the binding energies of ZnO and Ni. The presence of Zn-O vibrational modes was identified by FTIR spectra. The morphology of prepared samples was investigated through SEM and TEM analysis. The presence of Zn, O and Ni elements in EDX spectra indicates the purity of the sample. The optical bandgap energy of ZnO nanoparticles decreases with an increase in Ni concentration. Antimicrobial activity of nanoparticles were carried out against s.aureus, B.subtilis and P.aeruginosa bacterial strains as well as the fungal strain of A.niger and C.albicans. ZnO nanoparticles have significant antioxidant activity against DPPH free radicals. Under solar irradiation, Zn0.93Ni0.07O nanoparticles exhibit excellent photocatalytic degradation against malachite green (98.4 %) and methylene blue (94.9 %) dye solutions. Finally, these findings suggest an effective utilization of phytochemicals present in the A.muricata leaf extract as a suitable source for biosynthesis of pure and Ni-doped ZnO nanoparticles utilised for biomedical and industrial waste water treatment applications.

Antibacterial Activities of Ethiopian Natural Honey Against Iron and Nickel-Doped ZnO Nanoparticles

In this work, the antibacterial activities of natural Ethiopian honey and iron (Fe)-/nickel (Ni)-doped ZnO nanoparticles against Gram-positive and Gram-negative bacteria were investigated. The test strains used were Staphylococcus aureus (S. aureus ATCC25923) and Escherichia coli (E. coli ATCC25922). The co-precipitation method was used to prepare Fe- and Ni-doped ZnO nanoparticles (NPs). The X-ray diffraction (XRD) study revealed that the prepared samples have hexagonal crystal structure with a preferred orientation along the (101) plane. The average crystal sizes for iron and nickel-doped NPs were 39.09[Formula: see text]nm and 34.30[Formula: see text]nm, respectively. The energy dispersive analysis of X-ray spectra (EDX) analyses confirmed the presence of Zn, O, Fe and Ni elements in the prepared NPs samples. A strong emission peak at 454[Formula: see text]nm was observed in the photoluminescence spectra of the NPs. In order to characterize the honey’s composition, variety of physico-chemical and optical approaches were used. The absorption spectra of the three samples of honey are comparable and exhibited a noticeable peak about 260[Formula: see text]nm. The FTIR analysis confirmed that the honey samples contained the expected functional groups. The agar well diffusion technique was used to investigate the antibacterial efficacy of Fe- and Ni-doped ZnO NPs as well as Ethiopian natural honey. The results show that against E. coli strains and S. aureus strains, respectively, Fe-doped and Ni-doped ZnO NPs had average inhibitory zones of 17.1[Formula: see text]mm, 15.7[Formula: see text]mm, 15.5[Formula: see text]mm and 14.7[Formula: see text]mm, respectively. Against the S. aureus strain, the natural honey displayed a maximal inhibition zone of 12.6[Formula: see text]mm and no inhibition zone at all for E. coli.

Terahertz characterizations of solution-processed Ni-doped, Cu-doped, and undoped ZnO nanoparticles

We present experimental studies on doped and undoped ZnO nanoparticles prepared via cost-effective solution processing techniques towards its applicability for terahertz frequency domain. Scanning electron microscopy (SEM) confirms that the dimensions of synthesised particles spread over 120–275 nm, while x-ray diffraction (XRD) along with energy dispersive x-ray (EDX) characteristics manifests the presence of the desired materials for doped as well as undoped nanoparticles. Further, terahertz-time domain spectroscopy (THz-TDS) data are recorded in transmission mode which are employed to extract several optical parameters (viz. refractive index, conductivity, etc) of the nanoparticulate films spanning the frequency range from 0.2 to 0.9 THz. Doped samples clearly manifest enhanced conductivities because of the presence of metallic components. Cost-effective synthesis of ZnO nanoparticles can be useful for terahertz photonics in future.

XRD STRUCTURE STUDY ON NICKEL DOPED ZINC OXIDE NANOPARTICLES SYNTHESIZED BY COPRECIPITATION METHOD

Nickel-doped Zinc Oxide (Zn(1-x)Ni(x)O) nanoparticles have been synthesized by the chemical coprecipitation method. The structure and characteristic of synthesized Ni doped ZnO nanoparticles ware analyzed by X-ray diffraction (XRD) patterns. Crystallite sizes and lattice strain of all samples were calculated using the Scherrer’s formula, Uniform Deformation Model (UDM) and Halder-Wagner (H-W) method. X-ray diffraction analysis confirmed hexagonal cubic structure of Ni-doped ZnO nanoparticles. Also, the crystallite size of the nanoparticles reduces as the nickel concentration increase. The result showed the average crystallite size calculated by Scherrer’s formula (25-29 nm) was smaller than crystallite size using UDM method (51-63) the largest average crystallite size and H-W method (42-47 nm). The lattice strain increases with decreasing crystallite sizes value. The crystal size Ni- doped ZnO nanoparticles decreased with increasing dopant concentration.

Green synthesis of Ni doped ZnO nanoparticles using dandelion leaf extract and its solar cell applications

In designing sub-100nm nanoparticles (NPs), the “green synthesis” method has drawn considerable interest in recent years due to its sustainable, reliable, and eco-friendly in nature. The green synthesis method successfully eradicates the harmful and/or toxic effects usually associated with wet chemical methods. Different concentrations of Ni2+ ion doped ZnO NPs were synthesized by using dandelion leaf, an eco-friendly and green synthesis method at ∼70 °C for 0.5 h and annealed the NPs at 600 °C for 3 h to grow the crystalline nature of the NPs. The Ni2+ ion doped ZnO NPs were surface modified to enhance the dispersion ability of the NPs in aqueous solvents. NPs with surface modifications are readily dispersed in water and further surface functionalization can be performed. NPs are characterized by XRD, SEM, EDX, FTIR, and UV–Vis. XRD confirms the high crystallinity and Ni2+ ion saturation limit ∼5% in ZnO NPs with hexagonal-Wurtzite phase structure. Shifting of diffraction angle to higher angles clearly shows successful incorporation of Ni2+ ions in ZnO host. SEM images of the ZnO nanoparticles confirm the NPs are mostly spherical and sub-100nm in size. EDX results confirm the elemental composition and purity of the NPs, and no impurity peaks were detected. FTIR confirms the band at 410 cm−1 is assigned to asymmetric stretching of the Zn–O tetrahedron. A slight shift in this peak ∼10–20 cm−1 is observed by Ni2+ ion incorporation. Also, surface modified NPs show further surface vibrations, which supports high dispersibility of the NPs. The UV–Vis absorption study confirms the decrease in bandgap of NPs from 3.1 to 2.54 eV. In addition, Ni2+ doped ZnO NPs incorporated in PVA thin films and coated on polycrystalline silicon solar cells sustain strong UV–Vis absorption, supporting their use as for the enhancement of light harvesting efficiency.

Ni doping effect on the electronic, structural and optical properties of ZnO nanoparticles prepared by Co-precipitation route

Nanoparticles (NPs) synthesized by the co-precipitation technique show many attractive properties such as small particle size, high crystallinity, high average pore diameter and high specific surface area. However, numerous reports show that some characteristics of the Ni-doped ZnO (NZO) NPs remain controversial such as optical bandgap (Eg), surface morphology and defect level. In this study, pure ZnO and NZO NPs at different Ni contents (x) were successfully prepared using the co-precipitation method. Phase analysis confirms the hexagonal wurtzite crystallinity of the samples. XRD peak shows that the Ni may substituted ZnO structure as the peaks shift toward higher angles with increasing x. Meanwhile, the formation of NiO secondary phases was significant at 12.50% Ni content. Densely packed spherical shaped structures with nanoparticle agglomeration are observed at low x, while some nanorod shaped structures appear at higher x. The stretching vibrations of the Zn–O bond are observed in the NZO NPs. The absorption edge shifts to higher wavelengths with the increase in x. This study provides consistent results in the phase analysis, morphology and structural parameters. The decrease in Eg agrees with the photoluminescence measurements. The emission spectra confirm the presence of interstitial zinc and singly ionized oxygen vacancies.

Non-Bonding Interaction of Neighboring Fe and Ni Single-Atom Pairs on MOF-Derived N-Doped Carbon for Enhanced CO2 Electroreduction.

Single-atom catalysts (SACs), featuring high atom utilization, have captured widespread interests in diverse applications. However, the single-atom sites in SACs are generally recognized as independent units and the interplay of adjacent sites is largely overlooked. Herein, by the direct pyrolysis of MOFs assembled with Fe and Ni-doped ZnO nanoparticles, a novel Fe1-Ni1-N-C catalyst, with neighboring Fe and Ni single-atom pairs decorated on nitrogen-doped carbon support, has been precisely constructed. Thanks to the synergism of neighboring Fe and Ni single-atom pairs, Fe1-Ni1-N-C presents significantly boosted performances for electrocatalytic reduction of CO2, far surpassing Fe1-N-C and Ni1-N-C with separate Fe or Ni single atoms. Additionally, the Fe1-Ni1-N-C also exhibits superior performance with excellent CO selectivity and durability in Zn-CO2 battery. Theoretical simulations reveal that, in Fe1-Ni1-N-C, single Fe atoms can be highly activated by adjacent single-atom Ni via non-bonding interaction, significantly facilitating the formation of COOH* intermediate and thereby accelerating the overall CO2 reduction. This work supplies a general strategy to construct single-atom catalysts containing multiple metal species and reveals the vital importance of the communitive effect between adjacent single atoms toward improved catalysis.

Enhanced photocatalytic activities of facile auto-combustion synthesized ZnO nanoparticles for wastewater treatment: An impact of Ni doping

In the current work, we present the facile one-pot synthesis of 0.0, 0.5, 1.0, 2.0 and 3.0 wt% of Ni doped ZnO nanoparticles (Ni:ZnO NPs) through combustion route at 550 °C. Structural and vibrational studies approve the synthesis of monophasic hexagonal Ni:ZnO NPs. The crystallite size was calculated to be in the range of 36–60 nm for pure and doped samples. The composition of all elements in the final product along with their homogeneity, was approved through EDX/FESEM e-mapping analysis. The morphology and phase confirmation of the prepared samples was investigated through FESEM and TEM/HRTEM analyses. TEM/HRTEM study shows that the size of grains is within the range of 100 nm and grown along the c-axis as the lattice spacing is found ∼2.6005 Å. Diffused reflectance study was used to estimate the energy gap for all samples and found to reduce from 3.287 eV for pure to 3.258 eV for 3.0 wt% Ni doping. From an applications point of view, the photocatalytic performance of Ni:ZnO NPs was studied, and with 3.0 wt% of Ni doping in ZnO the degradation of methylene blue (MB) and tetracycline (TCN) pollutants were found to be remarkably improved.

Application of Ni-Doped ZnO Nanoparticles for the removal of 2,4-D Pesticide from aqueous Environment by Electro-photo catalytic Process

Application of Ni-Doped ZnO Nanoparticles for the removal of 2,4-D Pesticide from aqueous Environment by Electro-photo catalytic Process

Assessment of Magnetic Properties between Fe and Ni Doped ZnO Nanoparticles Synthesized by Microwave Assisted Synthesis Method

The emergence of Dilute Magnetic Semiconductors (DMS) with a potentials for spintronic application have attracted much researches attention, special consideration has been given to ZnO semiconductor material due to its wide band gap of 3.37 eV, large exciting binding energy of 60 meV, moreover, its ferromagnetic behavior at room temperature when doped with transition metals. MxZn1-xO (M = Fe or Ni) nanoparticles were synthesized by microwave assisted synthesis method calcined at 600°C. The structural, morphological and magnetic properties of these nanoparticles were studied using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Vibrating Sample Magnetometer (VSM) respectively. Single phase Wurtzite hexagonal crystal structure was observed for the undoped and Fe doped ZnO nanoparticles with no any impurity, whereas Ni doped ZnO nanoparticles shows the formation of NiO impurities. The magnetic measurement reveals a diamagnetic behavior for the undoped ZnO meanwhile a clear room temperature ferromagnetism was observed for both Fe and Ni doped ZnO. Fe doped ZnO present a high saturation magnetization compared to Ni doped ZnO. However, Ni doped ZnO present high coercivity. The research was confirmed that Fe doped ZnO material will be good material combination for spintronic applications.

Evaluation of stress factor on wheat (Triticum aestivum): the effect of ZnO and Ni-doped ZnO nanoparticles

Phytotoxicological evaluation of ZnO nanoparticles (NPs) is important to determine the possible effects on ecosystems. Although bulk Zn2+ ions can be used by plants as an essential micronutrient, it has many adverse effects on living organisms in nano-size. In this study, the growth, the development, and the stress effects of ZnO and Ni-doped (5%) ZnO NPs on wheat (Triticum aestivum – İkizce 96) were comparatively evaluated. In the growth and development experiments seed germination rate, root-shoot elongation, seedling vigor, plant height, and chlorophyll content in plants were determined, and the plant stress was evaluated depending on superoxide dismutase, catalase (CAT), and ascorbate peroxidase (APX) activities. It was observed that the height of the plants was decreased with increasing the NPs treatments. The seed germination and chlorophyll content were affected by neither the pure ZnO nor Ni-doped ZnO NPs. The effects of ZnO were more pronounced on superoxide dismutase while Ni:ZnO on CAT, and APX.