Fe-doped ZnO Nanoparticles Research Articles

Fe incorporation and modulation of oxygen vacancies in ZnO nanoparticles for photocatalytic degradation of Rhodamine B

In this study, self-assembled ultrafine nanoclusters of Fe2O3 supported with defective Fe-doped ZnO nanoparticles (NPs) prepared via calcination of a Fe/Zn precursor in the presence of deep eutectic solvents (DES) complex. During the calcination process, surface defects are generated through the decomposition of Fe/Zn precursor with DES complex, simultaneously crystallinity of catalysts improved. The hexagonal wurtzite structure of ZnO NPs is retained after the incorporation of Fe atoms into the ZnO crystal lattice. Notably, the particle size is reduced from 32 to 22 nm after Fe incorporation due to alterations in the nucleation center in the ionic solvent. Electron paramagnetic resonance analysis reveals a broad peak at a g value of 2.0, attributed to Fe3+ atoms doped into ZnO matrix. These doped Fe3+ atoms create additional active sites on the surface of NPs, leading to an extended photoluminescence lifetime of the Fe2O3/ZnO nanocomposite. Consequently, the optimized Vo-Fe/ZnO nanocomposite achieves a 95 % removal efficiency for Rhodamine B (RhB) degradation with a rate constant (k) of 0.0755 min−1. Additionally, nanocomposite shows visible light photo-Fenton activity for RhB degradation with k of 0.0069 min−1.

Tobacco stem extract-mediated green synthesis of Fe-doped ZnO nanoparticles towards enhanced photocatalytic degradation of methylene blue and solar cell efficiency

Tobacco stem extract-mediated green synthesis of Fe-doped ZnO nanoparticles towards enhanced photocatalytic degradation of methylene blue and solar cell efficiency

Development and analysis of Fe-doped ZnO nanoparticle-infused sisal fiber reinforced hybrid polymer composites for high-performance sound absorption and thermal insulation applications

In the current study, sisal fiber-reinforced hybrid composites have been developed by integrating a bidirectional mat with a blend of epoxy using Fe-doped ZnO (IDZO) nanoparticles at concentrations of 0.2, 0.4, 0.6, and 0.8 wt%. Hand-lay-up approach was used to create the composites. The composites were characterized through a comprehensive analysis of their density, water absorption, elasticity, thermogravimetric analysis, mechanical resistance, thermal conductivity, microhardness, and propagation of sound properties, including sound absorption coefficients and sound transmission class ratings. As filler loading increased, the bio-composite sample’s hardness increased under the density and void volume fraction values, with 0.8 wt% composite sample showing the superior micro-hardness. A positive correlation was observed between the ZnO nanoparticle weight percentage and thermal conductivity, with improve nanoparticle content leading to improved thermal performance. Composites containing 0.4 wt percent nanoparticles showed superior tensile strength (66.8–84.16 MPa), flexural strength (97.69–120.02 MPa) and flexural modulus (3.56–7.68 GPa). It has been observed that the weight percentage of IDZO filler greatly influences the sound absorption efficiency of the current composites. These findings highlight the promising potential of these novel biocomposites in advanced engineering applications, emphasizing their usefulness in demanding environments with biodegradability and high-performance thermal, mechanical, and acoustic properties. Based on the sound transmission class ratings, the sisal fiber biocomposites have been regarded as great adoptions for use as sound-absorbing materials such as wall partitions, doors, enclosures, and structural components, thermal insulation systems, and electrical insulation.

Vaccinium macrocarpon Based Fe-Doped Zno Nanoparticles as an Alternate Against Resistant Uropathogens

Vaccinium macrocarpon Based Fe-Doped Zno Nanoparticles as an Alternate Against Resistant Uropathogens

Fe-doped ZnO nanoparticles prepared by high energy ball milling with enhanced sonophotocatalytic performance

Zinc oxidenanostructures were synthesized using a thermal decomposition method and subsequently doped with Fe (III)in this study. Techniques such as X-ray diffraction, Field emission scanning electron microscopy, and Fourier transform infrared spectroscopy were used to investigate the structural and chemical composition of nanomaterials. Fe-doped ZnO was synthesized using a simple, low-cost planetary high-energy ball milling process. The sonophotocatalytic activity of Fe-doped ZnO under visible light and ultrasonic waves was then studied. Another aspect of this study is the utilization of visible light, which is far more accessible and cost-effective than UV light. Malachite green (MG) and phenol were applied as water-soluble contaminants. MG degraded about 87.65% after 1 h in the presence of a Fe-doped ZnO catalyst under visible light and ultrasonic waves simultaneously. Phenolwas degraded by approximately 64.50% under the same conditions.

Natural honey (Mellifera) assisted combustion synthesis of ZnO, Ag-ZnO and Fe-ZnO nanoparticles for ethanol gas sensor applications

Biogenic combustion with Mellifera (Honey) capping produced ZnO, Ag-doped ZnO, and Fe-doped ZnO nanoparticles. The phase and crystal structure of metal oxide nanoparticles (MONPs) have been recorded through XRD spectrum. It confirms that the prepared metal oxides are within the nanoscale range. The average crystallite size of Fe-doped ZnO is 8.8 nm, smaller than ZnO and Ag-doped nanoparticles. The vibrational spectra of ZnO, Ag-doped ZnO, and Fe-doped ZnO nanoparticles confirm functional group stretching vibrational modes. The exterior surface morphology of all metal oxide nanoparticles was captured by FESEM. Metal oxide nanoparticle compositional analysis shows elemental presence, atomic, and weight %. The optical properties of metal oxide nanoparticles have been examined using UV–vis spectroscopy. The band gap energy of ZnO nanoparticles reduced from 2.68 eV to 1.74 eV under Fe doing and increased to 2.9 eV under Ag doing. Metal oxide thermal stability is also being investigated to determine how it affects ZnO nanoparticles. Fe-doped ZnO nanoparticles have greater sensor properties than other metal oxides due to their tiny size, band gap, and stability. Gas sensor behaviour of three metal oxide nanoparticles was examined in various accepts. It proves Fe-doped ZnO is a promising gas sensor material.

Iron(II)-induced defect luminescence and deconvolution of ferromagnetic and paramagnetic behaviour in Zn(1-x)FexO (x = 0.01, 0.03, 0.05) nanoparticles

Zn(1-x)FexO (x = 0.00, 0.01, 0.03, 0.05) nanoparticles (NPs) were prepared by co-precipitation method and the wurtzite phase was confirmed by x-ray diffraction (XRD). The average crystallite size changes from 36 nm to 26 → 23→22 nm as the Fe-doping level varies from 0 to 1% → 3% → 5 % and the lattice strain increases concomitantly. The pristine ZnO NPs exhibit well-defined peak at 370 nm in the UV–vis absorption spectra which gets broadened on Fe-doping. The photoluminescence (PL) spectra of the pristine ZnO NPs shows a dominant excitonic peak at 390 nm. On Fe(II)-doping, new PL peaks at 449, 490 and 525 nm appear that are attributed to Zn-interstitials (Zni), oxygen vacancies (VO) and Zn vacancies (VZn), respectively. For all the Fe-doped ZnO NPs, M vs H plots have a complex non-saturating appearance indicating combination of ferromagnetic (FM) and paramagnetic (PM) behaviors. The subtraction of PM contribution revealed the FM curves with saturation magnetization (Ms). On going from 1% to 5% Fe-doping, the Ms values increase substantially by 39 times (0.00361 → 0.1398 emu/g) whereas the paramagnetic susceptibility, χP, increased 35 times (0.28 × 10−6 → 9.72 × 10−6 emu g−1 Oe−1).

Mössbauer and magnetic studies of Fe-doped ZnO nanoparticles prepared by solution co-precipitation method

A series of Zn[Formula: see text]FexO ([Formula: see text], 0.015, 0.045, 0.075) nanoparticles were synthesized using the solution co-precipitation method, and their structural and property characteristics were investigated. X-ray diffraction (XRD) analysis revealed that all Zn[Formula: see text]FexO samples exhibited a hexagonal wurtzite crystal structure with the P63mc space group. The introduction of Fe doping led to a slight lattice distortion in the samples. The morphology of the nanoparticles, including polydispersion and agglomeration, as well as the presence of the second phase ZnFe2O4, was examined by scanning electron microscope (SEM) and transmission electron microscope (TEM). UV–Vis diffuse reflectance spectroscopy demonstrated that the band gap of Zn[Formula: see text]FexO lies between 3.152 and 3.163[Formula: see text]eV. With the increase in Fe ion doping, the band gap shows a slight decreasing trend. Mössbauer spectroscopy revealed that iron ions in the nanoparticles existed in a trivalent state and exhibited two different configurations: One involved iron replacing zinc without creating a vacancy, while the other involved iron substituting zinc with a vacancy. The ferromagnetic nature of the Fe-doped samples can be attributed to the exchange interaction between two Fe[Formula: see text] ions mediated by the F-center mechanism.

Synthesis and characterization of Fe doped ZnO nanoparticles for the photocatalytic degradation of Eriochrome Black-T dye

Synthesis and characterization of Fe doped ZnO nanoparticles for the photocatalytic degradation of Eriochrome Black-T dye

Preparation and characterization of Fe-ZnO cellulose-based nanofiber mats with self-sterilizing photocatalytic activity to enhance antibacterial applications under visible light.

Bacterial infections and antibiotic resistance have posed a severe threat to public health in recent years. One emerging and promising approach to this issue is the photocatalytic sterilization of nanohybrids. By utilizing ZnO photocatalytic sterilization, the drawbacks of conventional antibacterial treatments can be efficiently addressed. This study examines the enhanced photocatalytic sterilizing effectiveness of Fe-doped ZnO nanoparticles (Fe-ZnO nanohybrids) incorporated into polymer membranes that are active in visible light. Using the co-precipitation procedure, Fe-ZnO nanohybrids (Fe x Zn100-x O) have been generated using a range of dopant ratios (x = 0, 3, 5, 7, and 10) and characterized. The ability to scavenge free radicals was assessed and the IC50 value was calculated using the DPPH test at different catalytic concentrations. PXRD patterns showed a hexagonal wurtzite structure, which indicated that the particle size of the nanohybrid decreased as the dopant concentration rose. It was demonstrated by UV-vis diffuse reflectance experiments that the band gap of the nanohybrid decreased (redshifted) with Fe doping. The photocatalytic activity under sunlight increased steadily to 87% after Fe was added as a dopant. The Fe 5%-ZnO nanohybrid exhibited the lowest IC50 value of 81.44 μg mL-1 compared to ZnO, indicating the highest radical scavenging activity and the best antimicrobial activity. The Fe 5%-ZnO nanohybrid, which is proven to have the best photocatalytic sterilization activity, was then incorporated into a cellulose acetate polymer membrane by electrospinning. Disc diffusion assay confirmed the highest antimicrobial activity of the Fe 5%-ZnO nanohybrid incorporated electrospun membrane against Staphylococcus aureus (ATCC 25923), Streptococcus pneumoniae (ATCC 49619), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), and Candida albicans (ATCC 10231) under visible light. As a result, Fe 5%-ZnO nanofiber membranes have the potential to be employed as self-sterilizing materials in healthcare settings.

Electrochemical detection of tryptophan in fish and pharmaceutical supplement at glassy carbon electrode modified with Fe doped ZnO nanoparticle

AbstractThe co‐precipitation approach was employed in this study to create Fe doped ZnO (Fe‐ZnO) nanoparticles (NPs). To characterize the synthesized NPs, Ultra violet‐Visible (UV‐Vis) spectroscopy, X‐ray diffraction (XRD), fourier transform infrared (FT‐IR), scanning electron microscopy (SEM), and Brunauer‐Emmett‐Teller (BET) were used. Here, a novel electrochemical approach for the detection of tryptophan (Trp) using a glassy carbon electrode modified with Fe‐ZnO NPs (Fe‐ZnO/GCE) is demonstrated. The research findings revealed that Fe‐ZnO/GCE enhanced the electron transfer rate of Trp oxidation. The sensitivity of Trp detection using Fe‐ZnO/GCE in phosphate buffer solution (PBS) at pH 64.0 was significantly improved compared to bare GCE due to the electrocatalytic activity of Fe‐ZnO NPs. Fe‐ZnO/GCE exhibited a linear response with Trp concentrations ranging from 0.1 to 150 μM with the limit of detection (LOD) is 0.089 μM (3σ/m) and limit of quantification (LOQ) about 0.3 μM (10σ/m) using linear sweep voltammetry (LSV). The Fe‐ZnO/GCE sensor was also effectively used to detect Trp in African catfish and multivitamin tablets. Trp analysis in real samples exhibited good recovery values of 89.60 to 99.15 %, demonstrating the accuracy and practicality of the method.

Structural, optical and magnetic characteristics of iron doped zinc oxide thin films

Zn1-xFexO films with x = 0, 5, 10, 15 and 20 at.% were prepared under high vacuum by the electron beam gun evaporation. The impact of Fe doping concentration on the films' structural, optical and magnetic characteristics has been taken into account. The patterns of XRD for all films at various Fe concentrations showed wurtzite-type structures. The results show that the size of nano-films reduces from 24 nm (0%) to 11 nm (0.20%) with elevating Fe content, which is owing to the difference between the ionic radii of Zn and Fe. Peaks associated with the elements to be seen were visible in the XPS spectra of undoped and 10% Fe-doped ZnO nanoparticles produced by the precipitation process: zinc (Zn), iron (Fe), and oxygen (O). The optical constants (n, k) of the Zn1-xFexO films were obtained by the SE measurements by an ellipsometric model, allowing for the verification of the Fe3+ ions in Fe-doped ZnO. With the addition of Fe, the energy band gap decreased from 3.44 eV to 3.28 eV. M-H measurements revealed room-temperature ferromagnetism in Fe-doped ZnO thin film. As the Fe concentration rises, the magnetization increases until it reaches a concentration of 15%, at which point it starts to decrease. This decrease in magnetization was attributable to the spinel phase, which was seen in the XRD spectra. These findings imply that Fe-doped ZnO is a highly suggested material for the creation of spintronic and optoelectronic devices.

Photoluminescence and Photocatalytic Properties of MWNTs Decorated with Fe-Doped ZnO Nanoparticles

The present work reports the photoluminescence (PL) and photocatalytic properties of multi-walled carbon nanotubes (MWCNTs) decorated with Fe-doped ZnO nanoparticles. MWCNT:ZnO-Fe nanocomposite samples with weight ratios of 1:3, 1:5 and 1:10 were prepared using a facile synthesis method. The obtained crystalline phases were evidenced by X-ray diffraction (XRD). X-ray Photoelectron spectroscopy (XPS) revealed the presence of both 2+ and 3+ valence states of Fe ions in a ratio of approximately 0.5. The electron paramagnetic resonance EPR spectroscopy sustained the presence of Fe3+ ions in the ZnO lattice and evidenced oxygen vacancies. Transmission electron microscopy (TEM) images showed the attachment and distribution of Fe-doped ZnO nanoparticles along the nanotubes with a star-like shape. All of the samples exhibited absorption in the UV region, and the absorption edge was shifted toward a higher wavelength after the addition of MWCNT component. The photoluminescence emission spectra showed peaks in the UV and visible region. Visible emissions are a result of the presence of defects or impurity states in the material. All of the samples showed photocatalytic activity against the Rhodamine B (RhB) synthetic solution under UV irradiation. The best performance was obtained using the MWCNT:ZnO-Fe(1:5) nanocomposite samples, which exhibited a 96% degradation efficiency. The mechanism of photocatalytic activity was explained based on the reactive oxygen species generated by the nanocomposites under UV irradiation in correlation with the structural and optical information obtained in this study.

Synthesis of Fe-doped ZnO by supercritical antisolvent precipitation for the degradation of azo dyes under visible light

Supercritical antisolvent precipitation was used to obtain ZnO (undoped) and Fe-doped ZnO photocatalysts at different Fe/Zn molar ratio percentages (0.57, 0.75 and 0.84 mol%). Wide-angle X-ray diffraction showed the hexagonal wurtzite as the main crystalline phase of the cauliflower-like nanoparticle aggregations (observed from Field Emission Scanning Electron Microscopy) with a mean diameter of 54.5 nm for the pure ZnO nanoparticles and a higher mean diameter (in the range 109.1–121.5 nm) for Fe-doped ZnO nanoparticles. XRF confirmed the approximate Fe/Zn ratios (0.55, 0.77, 0.82 mol%). The band gap energy, derived from UV − Vis diffuse reflectance measurements decreased upon Fe doping with values ranging from 3.22 (ZnO) to 2.83 eV (0.57 mol%Fe). The photocatalytic activity results showed that the undoped ZnO photocatalyst completely removes color from an aqueous solution containing Acid Orange 7 dye (AO7) after 30 min of UV light irradiation. Whereas Fe-doped ZnO photocatalyst with 0.75 mol% Fe content (0.75Fe) exhibited the highest discoloration efficiency (52 %) and total organic carbon (TOC) removal efficiency (∼36 %) of AO7 after 180 min under visible light. Moreover, the main reactive oxygen species involved in the AO7 degradation were assessed with the optimized photocatalyst (0.75Fe) in presence of scavenger molecules. The experimental results revealed that positive holes and superoxide are responsible for target dye degradation under visible light.

Photodegradation of methyl orange under solar irradiation on Fe-doped ZnO nanoparticles synthesized using wild olive leaf extract

Abstract Fe-doped ZnO nanoparticles (NPs) with different Fe contents (0.1–5.0 wt%) were prepared using extract of wild olive leaves growing in Saudi Arabia (region of Abha). The biosynthesized NPs were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer–Emmett–Teller, scanning electron microscopy, transmission electron microscopy, and photoluminescence (PL). Characterization results showed that undoped ZnO and Fe-doped ZnO powders were crystallized in the wurtzite structure with a small shift for the doped samples. Neither Fe3O4 nor another iron oxide phase was observed in the samples, which proves the incorporation of Fe into the ZnO lattice. Doping has a pronounced effect on the physical and optical properties. Indeed, the size of the crystallites, the energy of the bandgap as well as the intensity of the PL emission decreased with the Fe content. Photocatalytic tests revealed that the doped samples degraded methyl orange (MO) more efficiently than pure ZnO and pure Fe3O4. Moreover, the photocatalytic activity improved with increasing Fe content. The best photocatalyst of the series (Fe–ZnO-5) was found degrading MO by 92.1%, in 90 min in a pseudo-first order reaction.

Decolorisation of Congo red synthetic solution using Fe doped ZnO nano particles and optimization using response surface methodology

Sorption potential of synthesized nano particles were synthesized by co-precipitation method. Particles were characterized by SEM, XRD, FTIR, and EDX. Optimum adsorption conditions were determined as a function of contact time, pH (2 to 9), Initial concentration C0 (10, 20, 30, 50 mg/L), temperature T (283 to 323 K) and dosage (0.5 to 3 g/L). In order to find the adsorption characteristics isotherms applied to experimental data are Langmuir, Freundlich, Temkin and Harkin–Jura. The thermodynamic properties of the sorption (ΔHo, ΔSo and ΔGo) were obtained at different temperature and results show that adsorption was exothermic nature, spontaneous, more favorable at lower temperature under examined conditions. The above-mentioned process variables were performed and compared with Response Surface Methodology (RSM) values.

The role of pH on the vibrational, optical and electronic properties of the Zn1-xFexO compound synthesized via sol gel method

Herein, was investigated the role of pH on vibrational, morphological, optical, and electronic properties for pure and Fe-doped ZnO nanoparticles. The Zn1-xFexO compound with x = 0.00 and 0.02, were synthesized by the sol gel method with pH = 3, 6 and 9. For pure (x = 0.00) and Fe-doped (x = 0.02) ZnO samples Raman spectra showed slight variations, as the pH changed from the acidic to alkaline state. Two vibrational modes (580 cm−1 and 650 cm−1) were observed for Fe-doped samples, with shifted increasing as the pH values grow. Fourier transform infrared analysis revealed functional groups confirming the ZnO hexagonal structure for all x values. The samples corresponding to lower pH values showed spherical particles that are self-assembled to form irregular three-dimensional prisms-like, while the samples synthesized with basic and alkaline pH, the spherical nanoparticles are self-assembled in plates meshes-like. Pure and Fe-doped samples showed optical band gap values lower than expected for the bulk ZnO, with the lowest values for compounds synthesized at acidic pH (band gap = 3.23 ± 0.05 eV for pure ZnO and 3.21 ± 0.06 eV for Fe-doped ZnO). Structural defects such as zinc vacancies, interstitial zinc, singly ionized oxygen vacancy, and doubly ionized oxygen vacancy were detected through the photoluminescence spectra. The pH effect on electronic properties for pure and Fe-doped ZnO nanoparticles was also confirmed by electron paramagnetic resonance (EPR) measures. The simulation of EPR data for the spin S = 5/2 (Fe3+) demonstrated that pH variation induces strains in the ZnO lattice.

Investigation of the iron doping on the structural, optical, and magnetic properties of Fe-doped ZnO nanoparticles synthesized by sol–gel method

Investigation of the iron doping on the structural, optical, and magnetic properties of Fe-doped ZnO nanoparticles synthesized by sol–gel method

Green synthesis and characterization of Fe doped ZnO nanoparticles and their interaction with bovine serum albumin

Herein we report an eco-friendly and cost efficient synthesis of Fe doped ZnO (TPFZO) nanoparticles using the extract of Thespesia polpulanea flowers as a stabilizing agent. The synthesized NPs have been characterized by XRD, FT-IR, UV-DRS, SEM, EDAX and TEM studies. The synthesized NPs were found to have the crystallite size in the range of 30–60 ​nm. The calculated band gap energies for ZO and TPFZO nanoparticles were 3.00 ​eV and 1.97 ​eV respectively. The size distribution of the ZO and TPFZO obtained from TEM were observed to be lying in the range 50–120 ​nm and 4–22 ​nm respectively. The interaction of TPFZO NPs with bovine serum albumin (BSA) has been studied using fluorescence and absorption titration methods. The results indicated that the nanoparticles quenched the BSA fluorescence at 340 ​nm via static quenching mode having a bimolecular quenching rate constant value of 6.21 ​× ​1013 Lmol−1s−1.

Bio-ingredients assisted synthesis of Fe doped zinc oxide nanostructures: Study on structural, optical, morphological and thermal properties

Bio-ingredients (animal urine and honey) assisted synthesis of Fe doped ZnO nanostructures has been reported. The structural, optical, morphological, and thermal properties of Fe–ZnO nanostructures were investigated using XRD, FTIR, FESEM, TEM, and TGA. The average crystallite size of Fe–ZnO nanostructures made with animal urine is 34.2 nm, while those made with honey have an average crystallite size of 8.8 nm. It indicates that the size of Fe–ZnO nanostructure crystallites was determined in part by reaction time. FESEM was used to verify the nanostructures of the spherical shaped nanoparticles, and the honey Fe–ZnO sample showed a uniform distribution of particles. EDX analysis confirmed the existence of Zinc (Zn), Iron (Fe), and Oxygen (O) in the synthesized sample. According to TEM photos of Fe–ZnO nanostructures, the particle size of the samples is well correlated with the crystallite size determined by XRD. The thermal stability of Fe–ZnO nanostructures, as well as the effect of these natural ingredients on thermal stability, has been investigated. The surface charge and Zeta potential value of Fe doped ZnO nanoparticles using honey and Animal urine have been analyzed. The obtained values confirm the honey used Fe–ZnO nanoparticles has higher stability (−22.7 mV) than the animal urine assisted sample (−10.1 mV).