Properties Of Zinc Oxide Nanoparticles Research Articles

In Vitro Evaluation of Antibacterial Properties of Zinc Oxide Nanoparticles alone and in Combination with Antibiotics against Avian Pathogenic E. coli

In Vitro Evaluation of Antibacterial Properties of Zinc Oxide Nanoparticles alone and in Combination with Antibiotics against Avian Pathogenic E. coli

Parameters affecting carbofuran photocatalytic degradation in water using ZnO nanoparticles

AbstractCarbofuran photodegradation in water using zinc oxide nanoparticles as a catalyst was examined as well as some parameters influencing its percentage degradation rate such as zinc oxide load, initial concentration of carbofuran, the temperature of the reaction, the initial pH of the solution, and doping of zinc oxide nanoparticles with 5% (w:w) silver. Zinc oxide and Ag‐doped zinc oxide nanoparticles were produced using solvothermal and photoreduction methods, respectively, and silver doping effects on the structural, optical, and photocatalytic properties of zinc oxide nanoparticles were investigated using XRD, UV‐VIS spectrophotometer, TEM, SEM, SEM/EDX, and FTIR. The average diameter of the synthesized samples was 26.6, 30.55 nm for undoped zinc oxide and Ag‐doped zinc oxide, respectively. Zinc oxide doping with silver did not change the shape of the zinc oxide crystal, but decreased the reflection in the visible region, as well as the energy of the bandgap, and increased the zinc oxide photocatalytic activity.

Effects of Chromium Doping on the Electrical Properties of ZnO Nanoparticles

Nanostructured ZnO has gained a considerable amount of attention due to its unique physical and chemical properties and due to its remarkable performance in the fields of optics, photonics and electronics. The scope of this work is to study the Structural, Optical and Electronic properties of Pure Zinc Oxide (ZnO) and Chromium doped Zinc Oxide nanoparticles. These nanoparticles were synthesized by low-temperature precipitation method at various concentrations in the range (Zn1-xCrxO; (x = 0, 0.1& 0.3)). The precursors used were analytical grade Zinc Nitrate Hexahydrate and Chromium Nitrate Nona hydrate. The synthesized nanoparticles were annealed at 400°C. The Structural property of the synthesized nanoparticles was analysed by XRD (X-Ray diffraction) and was confirmed to exhibit a crystalline hexagonal wurtzite structure with an average crystallite size of 55nm. The functional groups were analysed using FTIR (Fourier Transformed Infra-red spectroscopy). The Morphology was analysed by FESEM (Field Emission Scanning Electron Microscope) and a change in morphology from spherical to spindle like structure was observed. The Optical properties were analysed using UV-Vis spectroscopy, the absorption spectrum for electromagnetic spectrum was observed and the changes in the optical band gap of ZnO nanoparticles with Chromium dopant addition were calculated to be in the range of 3.6 eV. The Electrical property of the synthesised nanoparticles was analysed using Electrochemical Impedance Spectroscopy (EIS) and the conductivity was calculated to be in the range of 1.1e-07S/m.

Measurement of Electric and Magnetic Properties of ZnO Nanoparticles in the X-Band Using Nicolson–Ross–Weir Analysis

The electric and magnetic properties of zinc oxide (ZnO) nanoparticles (NPs) have been investigated through waveguide measurement in the x-band. Because of the advantages of the x-band, the application of the Nicolson–Ross–Weir (NRW) method was able to be used to extract the mentioned characteristics from the scattering parameters. The advantages of the NRW method are that it is fast and applicable to waveguides and coaxial lines, and it can also be used to determine both the permittivity and permeability. Therefore, the results show two main resonant frequencies at 9.279 GHz and 10.46 GHz. The response of the ZnO NPs for an incident electromagnetic wave implies that both capacitance and inductance behaviors can be observed. Finally, the obtained magnetic susceptibility characteristic confirms that the ZnO NPs are ferromagnetic over the frequency range from 8 GHz to 8.265 GHz and paramagnetic up to 12.5 GHz.

Effect of solvents on structural, optical and electrical properties of ZnO nanoparticles synthesized by microwave heating route

Herein, we have studied the effects of solvents on structural, optical and electrical properties of prismatic shaped zinc oxide (ZnO) nanoparticles synthesized through microwave heating method. The samples were prepared by using various solvents viz., water (WT), digol (DEG), 2-propanol (2-PL) and ethylene glycol (EG). The XRD (X-ray diffraction) and FE-SEM (Field emission scanning electron microscopy) results confirmed that the crystallite size and growth of ZnO nanoparticles depended on the solvents used. EDAX analysis evaluates the Zinc (Zn) and oxygen (O) composition in the synthesized ZnO nanoparticles. The absorbance and reflectance studies were undertaken by UV–Visible spectroscopy. The energy gap of synthesized ZnO nanostructures was calculated using Kubelka-Munk plot. I-V characterization study was performed to estimate the current intensity of ZnO films.

Effect of Benzalkonium Chloride on Properties of Zinc Oxide Nanoparticles Synthesized through Sol-Gel Technique

In the present study, to synthesize controllable sized metal oxide particles, benzalkonium chloride (BAK) as cationic surfactant was added to zinc oxide (ZnO) nanostructures synthesis at room temperature using sol–gel method. The effect of cationic surfactant BAK concentrations, on the optical properties, size, and morphology of ZnO nanoparticles synthesized through sol–gel method was studied. The characterization of ZnO nanostructures was occurred using transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet–visible near infrared (UV-Vis) spectrophotometer, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). ZnO nanostructures shape and size were revealed by SEM and TEM. The hexagonal (wurtzite structure) of ZnO was confirmed by an X-ray diffractogram. The bandgap energy of the prepared ZnO samples was determined by UV-Vis spectrophotometer. FTIR analyzed the presence of functional groups.

Influence of alkali hydroxides on synthesis, physico-chemical and photoluminescence properties of zinc oxide nanoparticles

ZnO nanoparticles (NPs) have been synthesised by co-precipitation method using zinc nitrate in the presence of two different alkali hydroxides. The XRD analysis of as-prepared products, before and after washing demonstrates its importance in removal of the water soluble nitrates of alkali metals formed during co-precipitation. The X-ray diffraction patterns of the synthesised ZnO NPs confirm the formation of ZnO with hexagonal wurtzite phase. The ZnO NPs synthesised, as confirmed by the XRD pattern, in the presence of NaOH show comparatively smaller crystallite size. These quasi-spherical ZnO NPs show strong UV absorption and dominant visible PL emission, suitable for biomedical and photocatalytic applications.

Application of Modified PANI-ZnO Composites for NH3Gas Sensor at Ambient Temperature

Polyaniline and zinc oxide nanoparticles were successfully synthesized through inverse emulsion polymerization method and hydrothermal method respectively. For ammonia gas sensing using LCR meter thin film of the composite was fabricated by using spin coater. The functional groups, morphological, optical, structural properties of zinc oxide nanoparticles, polyaniline (emeraldine salt) and composites were investigated by FTIR spectroscopy, Scanning electron microscopy (SEM), UV- Visible spectroscopy and XRD analysis. The formation of ZnO particles of different shapes in the nano range was confirmed from UV-visible and XRD analysis. UV visible spectrum shows the formation of nanoparticles of ZnO. Thin film of Polyaniline/zinc oxide composites were deposited on the surface of copper interdigitated electrode. The fabricated device showed sensitivity to ammonia gas (NH3) at ambient temperature (300 K). It was observed that the resistance is decreases with the increase of volume of ammonia gas. The electrical properties were also investigated of the different concentration of nanocomposite. Optimum sensing response was achieved with PANI in the presence of 50 wt% ZnO nanoparticles. It may also be inferred from this study that the solution mixing process to produce composites has promising future if handled carefully.

Application of Modified PANI-ZnO Composites for NH3Gas Sensor at Ambient Temperature

Polyaniline and zinc oxide nanoparticles were successfully synthesized through inverse emulsion polymerization method and hydrothermal method respectively. For ammonia gas sensing using LCR meter thin film of the composite was fabricated by using spin coater. The functional groups, morphological, optical, structural properties of zinc oxide nanoparticles, polyaniline (emeraldine salt) and composites were investigated by FTIR spectroscopy, Scanning electron microscopy (SEM), UV- Visible spectroscopy and XRD analysis. The formation of ZnO particles of different shapes in the nano range was confirmed from UV-visible and XRD analysis. UV visible spectrum shows the formation of nanoparticles of ZnO. Thin film of Polyaniline/zinc oxide composites were deposited on the surface of copper interdigitated electrode. The fabricated device showed sensitivity to ammonia gas (NH3) at ambient temperature (300 K). It was observed that the resistance is decreases with the increase of volume of ammonia gas. The electrical properties were also investigated of the different concentration of nanocomposite. Optimum sensing response was achieved with PANI in the presence of 50 wt% ZnO nanoparticles. It may also be inferred from this study that the solution mixing process to produce composites has promising future if handled carefully.

Effect of Cationic Surfactants on Properties of Zinc Oxide Nanoparticles Synthesized through Sol-gel Technique

Zinc oxide (ZnO) is an important metal oxide which participates in lots of applications, including gas sensors, catalysis, and optoelectronic devices. For nanostructured materials, agglomeration is problematic in the chemical production processes. In surfactant-free chemical reactions, aggregation occurs immediately as particles are generated. Therefore, the synthesis of controllable size nanoparticles is of great fundamental and technological interest. In the present study, the effect of cationic surfactants such as cetyltrimethylammonium bromide and benzalkonium chloride concentrations, on the optical properties, size, and morphology of ZnO nanoparticles synthesized through sol-gel method were studied. The characterizing tools were X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and ultraviolet-visible (UV-Vis-near-infrared) spectrophotometer. X-ray diffractogram confirmed the hexagonal (wurtzite structure) of ZnO. FTIR analyzed the presence of functional groups. The shape and size of the ZnO nanostructures were revealed by SEM and TEM. The band gap energy of the prepared ZnO samples was determined by UV-Vis spectrophotometer.

Significant effects of temperature on biological properties of ZnO

Zinc oxide (ZnO) is an inorganic compound and it usually appears as a white powder. The powder is widely used as an additive into numerous materials. Inorganic nanoparticles are made by combining organic materials with inorganic materials which forms hybrids and has unique properties. The biological properties of zinc oxide nanoparticles like absorption coefficient, refractive index, concentration, conductivity, pH-values and temperatures were investigated. The diffusion techniques facilitate the measurement of the biological properties of liquids. The results show that absorption coefficient decreases with increasing the thickness of the zinc oxide pellet. The resistivity of the ZnO decreases with increasing the temperature was observed. The concentration of the sample increases conductivity also decreases. Zinc oxide refractive index changes with wavelength. The pH depends on temperature and biological effects were observed at lower concentration and which are playing a vital role in the metabolism of human beings and plant systems. The pH-profiles were measured after 24 h. One-way ANOVA showed significant differences of all tested materials. Variant refractive index can generate resonant cavity that can enhance phase shift of output light and fabricate a variety of optoelectronic device. Materials of high thermal conductivity are widely used in heat sink applications and materials of low thermal conductivity are used as thermal insulation. The biological properties like absorption coefficient, refractive index, concentration, conductivity, pHvalues and temperature were used in many advanced biological, medical and engineering applications such as heat exchangers.

The photothermal property of zinc oxide nanoparticles in the infrared spectrum

Based on the discrete dipole approximation (DDA) algorithm, the absorption spectra and near electric field of ZnO nanospheres with the radius of 10−30 nm in the infrared band were calculated. The position of absorption peak is slight blue-shift when the particle radius increases, and it is red-shift with the ambient refractive index. The near-field enhancement was calculated at the resonance wavelength, the results show that it increases with the particle radius, but it decreases with the ambient refractive index. The spatial distribution of temperature was analyzed when ZnO nanoparticle was incident by infrared light, and it was found that the maximum of temperature rising inside the particle increases with the absorption cross-section of the particle.

Kinetic and isothermal study of effect of transition metal doping on adsorptive property of zinc oxide nanoparticles synthesized via green route using Moringa oleifera leaf extract

In this study, a green route has been adopted to successfully synthesize pure zinc oxide nanoparticles (ZnONPs) as well as Cu doped zinc oxide nanoparticles (Cu-ZnONPs) which is quite a novel work. The synthesized nanoparticles (NPs) were used as adsorbent for removal of Congo red (CR) dye from aqueous solution and efficiency of both doped and undoped ZnONPs was investigated and evaluated. The synthesized products were further characterized and confirmed by UV–visible (UV–vis), Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), Thermo gravimetric Analysis (TGA), Transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Cu-ZnONPs were found to be more efficient adsorbent as compared to undoped ZnONPs. The adsorption process of CR on both the synthesized NPs were scrutinized using kinetics and isothermal parameter respectively, which depicted that the adsorption process in case of doped ZnONPs was faster (adsorption reached equilibrium in 120 min) as compared to undoped ZnONPs (which took 180 min) and followed a pseudo-second-order kinetics in both the cases. When pure ZnONPs was used as adsorbent, it correlated more with the Freundlich isotherm and Temkin isotherm as compared to Langmuir isotherm, however, when Cu-ZnONPs was used as adsorbent, the data fitted well to Langmuir and Freundlich models.

Influence of Al and Al-Cu dual doping on structural, optical, wetting and anti-fungal properties of ZnO nanoparticles

ABSTRACT Sol-gel (SG) and direct precipitation (DP) routes were employed to synthesize zinc oxide (ZnO) nanoparticles. Al doping and Al-Cu dual doping in ZnO nanoparticles were performed. The structural, morphological, optical, wetting properties and antifungal activity of the undoped and doped nanoparticles were studied. The Al doping transformed the ZnO to zinc aluminate nanostructure, while Al-Cu dual doping produced zincite and tenorite phases of ZnO. FESEM revealed the morphology of undoped and doped nanoparticles. The doping of ZnO increased the band gap compared to the band gap of the ZnO nanoparticles. Photoluminescence (PL) spectroscopy endorsed the formation of zinc aluminate, zincite and tenorite phases. The hydrophilic SG-derived ZnO nanoparticles transformed to the hydrophobic due to Al doping which is attributed to the variation in the roughness of the doped nanostructures. The doped ZnO nanostructures revealed better resistance to the growth of the ‘Rhizopus Stolonifer’ fungus compared to the undoped ZnO nanoparticles.

Effect of hydrogen annealing on structure and dielectric properties of zinc oxide nanoparticles

In this article, Zinc Oxide (ZnO) samples were synthesized by Co-precipitation method. The influence of hydrogen annealing on the structure and dielectric behavior of zinc oxide nanoparticles was investigated. X-ray diffraction measurements indicate that all the particles possess a typical wurtzite structure without any other impurity phases. The structure and size of these nanoparticles are not influenced by hydrogen annealing but a small change in the peak position and intensity was observed. The low-temperature dielectric study of the samples was studied in the frequency range 20 Hz to 1 MHz between 80 K and 300 K and these measurements show that the ZnO nanoparticles further annealed at hydrogen atmosphere exhibit a high dielectric permittivity and a large increase in ac conductivity compared to that of the corresponding ZnO nanoparticle annealed in air.The hydrogen occupancy of oxygen atoms to play an important role in enhancing dielectric permittivity and conductivity in ZnO nanoparticles.

Synthesis, characterization, and catalytic properties of zinc oxide nanoparticles for the treatment of wastewater in the presence of natural sunlight

Zinc oxide nanoparticles were synthesized using monochloro acetic acid as a complexing agent. These synthesized nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, UV–visible, energy-dispersive X-ray, Fourier transform infrared spectroscopy analysis, and BET techniques. As-prepared ZnO nanoparticles show crystalline nature with hexagonal dominant crystal phase. The SEM image shows the formation of homogenous micro-porous nanoparticles of ZnO. The photocatalytic activity of ZnO materials was measured on UV–visible spectrophotometer under natural sunlight irradiation and shows the efficiency (ɳ) of 56.80% in 150 min of time. A ZnO nanoparticle shows an excellent photocatalytic activity and can be used for the treatment of wastewater.

ZnO nanoparticles photocatalytic activity toward atmospheric toluene under simulated sunlight

In this study, the photocatalytic degradation of toluene through zinc oxide (ZnO) nanoparticles coated on glass plates was examined under simulated sunlight. Heat attachment procedure was employed to immobilize ZnO nanoparticles on glass plates. Removal performance of these prepared plates for toluene degradation was evaluated in a rectangular reactor under irradiation of metal halide lamp. The effects of operational parameters including initial toluene concentration, temperature, relative humidity, irradiation time, and concentration of zinc oxide suspension on the removal of toluene were investigated. The structural properties of ZnO nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The concentration of toluene was analyzed by gas chromatography with flame ionization detector (GC-FID). The results of the present study indicated that ZnO-coated glass plates resulted in removal of 67% toluene for concentration of 50 ppm at temperature 45 °C, and relative humidity of 40% after 240 min irradiation of metal halide light. As the glass plates coated by ZnO have relatively good performance under experimental conditions, it concluded that coating ZnO nanoparticles on surfaces can be considered as an environmentally friendly method to eliminate low concentration of toluene from polluted air under sunlight.

Structural optical and magnetic properties of transition metal doped ZnO magnetic nanoparticles synthesized by sol-gel auto-combustion method

Abstract Transition metals, such as chromium (Cr) and manganese (Mn) doped zinc oxide (ZnO) magnetic nanoparticles, were synthesized via sole gel auto-combustion method. The prepared magnetic (Zn1−(x+y)MnxCryO, where x, y = 0, 0.02, 0.075) nanoparticles were calcined in an oven at 6000 °C for 2 hours. The morphologies of the nanoparticles were investigated using different techniques. X-ray diffraction (XRD) analysis revealed that the hexagonal wurtzite structure of the synthesized nanoparticles was unaffected by doping concentration. The crystallite size measured by Scherrer formula was in the range of 32 nm to 38 nm at different doping concentrations. Nanosized particles with well-defined boundaries were observed using a field emission scanning electron microscopy (FE-SEM). Fourier transform infrared (FT-IR) spectra showed a wide absorption band around 1589 cm−1 in all the samples, corresponding to the stretching vibration of zinc and oxygen Zn–O bond. A blue shift in optical band gaps from 3.20 eV for ZnO to 3.08 eV for Zn0.85Mn0.075Cr0.075O nanoparticles was observed in diffuse reflectance spectra, which was attributed to the sp-d exchange interactions. The field-dependent magnetization M-H loops were measured using vibrating sample magnetometer (VSM). The VSM results revealed diamagnetic behavior of the ZnO nanoparticles which changed into ferromagnetic, depending on the doping concentration and particle size. The compositions of Zn, Cr, Mn and O in the prepared samples were confirmed by using the energy dispersive X-ray spectroscopy (EDX). Our results provided an interesting route to improve magnetic properties of ZnO nanoparticles, which may get significant attention for the fabrication of magnetic semiconductors.

Simple Combustion Synthesis, Structural, Morphological, Optical and Catalytic Properties of ZnO Nanoparticles

In this present study, semiconductor zinc oxide (ZnO) nanoparticles were successfully prepared by microwave irradiation (ZnO-MIM) and conventional combustion (ZnO-CCM) method, respectively using Aloe vera plant extract as reducing agent. Crystal structure, purity and surface morphology of the samples were examined by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. UV-Visible diffuse reflectance (DRS) and photoluminescence (PL) spectral studies was used to analysis the optical property and band gap energy of the samples. The antibacterial activities of ZnO nanostructures (ZnO-MIM and ZnO-CCM) were tested against both gram positive (Bacillus subtilis, Staphylococcus aureus) and gram negative bacteria (Proteus mirabilis, Salmonella typhi) by modified disc diffusion method and observed enhanced activity against P. mirabilis and S. typhi. ZnO nanostructures (ZnO-MIM and ZnO-CCM) were used as the photo-catalysts for the degradation of methylene blue (MB) dye and observed enhanced efficiency of degradation of MB than that of their same bulk materials. Moreover, the synthesis method is easy with low cost and time consumable and also high yield purity products.

Assessment of synthesis approaches for tuning the photocatalytic property of ZnO nanoparticles

Tuning the photocatalytic property of zinc oxide (ZnO) nanoparticles (NPs) is timely. Dependence of photocatalysis upon size, morphology and effective surface area of the particles used has led to optimization in various synthesis procedures. The current article addresses to dictate a cost-effective, bio-friendly, modified ease-process for this issue. The synthesis of ZnO NPs with differing photophysical properties, sizes and morphologies, in order to tune its photocatalytic activity, have been extensively studied. Polyethylene glycol as the structure directing agent and different synthesis strategies were adopted. Spectroscopic and microscopic characterization techniques were employed to understand the nature of the as-synthesized samples. Photocatalytic property and photostability of the samples were determined based on experiments performed with common xanthene and azo dyes. Based on analysing the results, certain characteristics, such as smaller particle size, less agglomerated structure, higher surface area and superior lifetime of the photogenerated electrons and holes upon light illumination, were essential for ZnO NPs to act as an efficient photocatalyst.