scholarly journals Unravelling the Role of Synthesis Conditions on the Structure of Zinc Oxide-Reduced Graphene Oxide Nanofillers

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2149 ◽  
Author(s):  
Zélia Alves ◽  
Cláudia Nunes ◽  
Paula Ferreira
Keyword(s):  
Zinc Oxide ◽  
Graphene Oxide ◽  
Zinc Acetate ◽  
Zinc Acetate Dihydrate ◽  
Average Particle Size ◽  
Antimicrobial Activities ◽  
Average Particle ◽  
Zno Nanostructures ◽  
Synthesis Conditions

The diversity of zinc oxide (ZnO) particles and derived composites applications is highly dependent on their structure, size, morphology, defect amounts, and/or presence of dopant molecules. In this work, ZnO nanostructures are grown in situ on graphene oxide (GO) sheets by an easily implementable solvothermal method with simultaneous reduction of GO. The effect of two zinc precursors (zinc acetate (ZA) and zinc acetate dihydrate (ZAD)), NaOH concentration (0.5, 1 or 2 M), and concentration (1 and 12.5 mg/mL) and pH (pH = 1, 4, 8, and 12) of GO suspension were evaluated. While the ZnO particle morphology shows to be precursor dependent, the average particle size length decreases with lower NaOH concentration, as well as with the addition of a higher basicity and concentration of GO suspension. A lowered band gap and a higher specific surface area are obtained from the ZnO composites with higher amounts of GO suspension. Otherwise, the low concentration and the higher pH of GO suspension induce more lattice defects on the ZnO crystal structure. The role of the different condition parameters on the ZnO nanostructures and their interaction with graphene sheets was observed to tune the ZnO–rGO nanofiller properties for photocatalytic and antimicrobial activities.

Research on Preparation, Characterization of Novel Nano-ZnO

2011 ◽  
Vol 311-313 ◽  
pp. 549-554
Author(s):  
Yan Yan Liu ◽  
Dian Mo Zheng
Keyword(s):  
Thermal Decomposition ◽  
Zinc Oxide ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Zinc Acetate ◽  
Average Particle Size ◽  
Molar Ratio ◽  
Average Particle ◽  
Acetate Solution ◽  
Nano Zno

Zinc acetate and ammonium bicarbonate are used as raw material, zinc oxide prepared by direct precipitation of new technology. This paper discusses the effection of the formation in zinc oxide from the reactant concentration of zinc acetate, HCO3-/Zn2+ molarity ratio, reaction temperature, reaction time and condition in thermal decomposition of basic zinc carbonate. Using transmission electron microscopy (TEM), thermogravimetric / differential thermal analysis (TG / DTA) and other methods, preparation of nano-ZnO are characterized. Good conditions for the better system of nano- ZnO are 0.75mol /L in the concentration of zinc acetate solution, 2.5:1 in bicarbonate of ammonia and zinc acetate molar ratio, 45 °C of reaction temperature, 1.0h of reaction time, and 350 °C in thermal decomposition temperature, 3.0h of pyrolysis time. Zinc oxide obtained average particle size is 20 ~ 80nm, for the hexagonal crystal form.

scholarly journals Comparative study on zinc oxide nanocrystals synthesized by two precipitation methods

Cerâmica ◽  
2018 ◽  
Vol 64 (369) ◽  
pp. 91-96 ◽  
Author(s):  
M. R. Bodke ◽  
Y. Purushotham ◽  
B. N. Dole
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Band Gap ◽  
Energy Band ◽  
Zinc Acetate Dihydrate ◽  
Average Particle Size ◽  
Chemical Compositions ◽  
Average Particle ◽  
Nitrate Hexahydrate ◽  
Energy Band Gap

Abstract Zinc oxide nanocrystals were synthesized by two precipitation methods successfully. The nanocrystals prepared via method I (zinc acetate dihydrate precipitation with KOH) were smaller in crystallite size (~20 nm) as compared to method II (zinc nitrate hexahydrate precipitation with N,N-dimethylformamide, ~33 nm). FTIR technique was used to study chemical bonding; SEM and EDS were used to study morphology and chemical compositions. Number of concentric rings corresponding to diffraction peaks was higher in SAED pattern for ZnO nanocrystals synthesized by method I than II. Variation in the energy band gap as a function of particle size was determined using absorption spectra from UV-vis-NIR spectrophotometer. Redshift was observed in the energy band gap of sample prepared via method II. Particle size and the structure of the nanocrystals were analysed by transmission electron microscope (TEM). From TEM study, it was found that the average particle size of method I nanocrystals was smaller compared to method II nanocrystals. Magnetic study was carried out using VSM. Ferromagnetism like contribution was observed for the sample prepared by method II.

scholarly journals Structural and Magnetic Properties of Co‒Mn Codoped ZnO Nanoparticles Obtained by Microwave Solvothermal Synthesis

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 410 ◽  
Author(s):  
Jacek Wojnarowicz ◽  
Myroslava Omelchenko ◽  
Jacek Szczytko ◽  
Tadeusz Chudoba ◽  
Stanisław Gierlotka ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Doping Level ◽  
Solvothermal Synthesis ◽  
Zinc Acetate Dihydrate ◽  
Average Particle Size ◽  
Average Crystallite Size ◽  
Average Particle ◽  
Acetate Tetrahydrate ◽  
Preparation Methods

Zinc oxide nanoparticles codoped with Co2+ and Mn2+ ions (Zn(1−x−y)MnxCoyO NPs) were obtained for the first time by microwave solvothermal synthesis. The nominal content of Co2+ and Mn2+ in Zn(1−x−y)MnxCoyO NPs was x = y = 0, 1, 5, 10 and 15 mol % (the amount of both ions was equal). The precursors were obtained by dissolving zinc acetate dihydrate, manganese (II) acetate tetrahydrate and cobalt (II) acetate tetrahydrate in ethylene glycol. The morphology, phase purity, lattice parameters, dopants content, skeleton density, specific surface area, average particle size, average crystallite size, crystallite size distribution and magnetic properties of NPs were determined. The real content of dopants was up to 25.0% for Mn2+ and 80.5% for Co2+ of the nominal content. The colour of the samples changed from white to dark olive green in line with the increasing doping level. Uniform spherical NPs with wurtzite structure were obtained. The average size of NPs decreased from 29 nm to 21 nm in line with the increase in the dopant content. Brillouin type paramagnetism and an antiferromagnetic interaction between the magnetic ions was found for all samples, except for that with 15 mol % doping level, where a small ferromagnetic contribution was found. A review of the preparation methods of Co2+ and Mn2+ codoped ZnO is presented.

scholarly journals Photoluminescences properties of lanthanum-silver co-doped ZnO nano particles

2018 ◽  
Vol 4 (4) ◽  
pp. 135-141 ◽  
Author(s):  
V. Porkalai ◽  
B. Sathya ◽  
D. Benny Anburaj ◽  
G Nedunchezhian ◽  
S. Joshua Gnanamuthu ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Zinc Acetate Dihydrate ◽  
Average Particle Size ◽  
Semiconductor Nanoparticles ◽  
Nano Particles ◽  
Average Particle ◽  
Rare Earth Ion ◽  
X Ray ◽  
Doped Zno ◽  
Co Doped

Recently, transition metal (TM) and rare earth ion doped II–VI semiconductor nanoparticles have received much attention because such doping can modify and improve optical properties of II–VI semiconductor nanoparticles by large amount. In this study, undoped, La doped and La+Ag co-doped ZnO nano particles have been successfully synthesized by sol-gel method using the mixture of Zinc acetate dihydrate and ethanol solution. The powders were calcinated at 600 °C for 2 h. The effect of lanthanum and lanthanum-silver incorporation on the structure, morphology, optical and electrical conductivity were examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Absorption (EDAX), Fourier transform infrared spectroscopy (FTIR), UV and Photo Luminescence (PL) Characterization. The average particle size of the synthesized ZnO nanoparticles is calculated using the Scherrer formula and is found to be of less than 20 nm. Luminescences properties were found to be enhanced for the La and La+Ag co-doped ZnO nanoparticles.

scholarly journals Effect of the polymeric coating over Fe3O4 particles used for magnetic separation

2010 ◽  
Vol 8 (5) ◽  
pp. 1041-1046 ◽  
Author(s):  
Raúl Reza ◽  
Carlos Martínez Pérez ◽  
Claudia Rodríguez González ◽  
Humberto Romero ◽  
Perla García Casillas
Keyword(s):  
Particle Size ◽  
Magnetite Nanoparticles ◽  
Average Particle Size ◽  
Spherical Shape ◽  
Polymeric Coating ◽  
Average Particle ◽  
Synthesis Conditions ◽  
Aging Conditions ◽  
Magnetite Particles ◽  
Average Size

AbstractIn this work, the synthesis of magnetite nanoparticles by two variant chemical coprecipitation methods that involve reflux and aging conditions was investigated. The influence of the synthesis conditions on particle size, morphology, magnetic properties and protein adsorption were studied. The synthesized magnetite nanoparticles showed a spherical shape with an average particle size directly influenced by the synthesis technique. Particles of average size 27 nm and 200 nm were obtained. When the coprecipitation method was used without reflux and aging, the smallest particles were obtained. Magnetite nanoparticles obtained from both methods exhibited a superparamagnetic behavior and their saturation magnetization was particle size dependent. Values of 67 and 78 emu g−1 were obtained for the 27 nm and 200 nm magnetite particles, respectively. The nanoparticles were coated with silica, aminosilane, and silica-aminosilane shell. The influence of the coating on protein absorption was studied using Bovine Serum Albumin (BSA) protein.

Preparation and Antibacterial Performances of Electrocatalytic Zinc Oxide Nanoparticles with Diverse Morphologies

2021 ◽  
Vol 17 (9) ◽  
pp. 1824-1829
Author(s):  
Junlin Li ◽  
Xiangfei Li ◽  
Dong Liang ◽  
Xiaojuan Zhang ◽  
Qing Lin ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Surface Area ◽  
Zinc Oxide Nanoparticles ◽  
Average Particle Size ◽  
Three Dimensional ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Zno Nps

This study exploits the potential of zinc oxide nanoparticles (ZnO-NPs) with diverse morphologies as catalysts and antibacterial agent. Spherical ZnO-NPs, rod-shaped ZnO-NPs and flower-shaped ZnO-NPs were prepared by microemulsion method, solvent heat method and hydrothermal method, respectively. The structural characterizations of samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. XRD results revealed the formation of spherical ZnO-NPs, rod-shaped ZnO-NPs and flower-shaped ZnO-NPs were all wurtzite crystal structure. SEM results showed that spherical ZnO-NPs had an average particle size of 30–40 nm, rod-shaped ZnO-NPs were about 500 nm long and 100 nm wide with obvious hexagonal crystals. Flower-shaped ZnO-NPs had a three-dimensional appearance with obvious petals. Results of electrochemical HER (Hydrogen evolution reaction) experiments revealed that spherical ZnO-NPs exhibited the highest electrocatalytic activity at the lowest potential voltage due to their largest specific surface area. The antibacterial property of ZnO-NPs samples were studied by the optical density method and disc diffusion method. All samples had antibacterial effects against E. coli. and flower-shaped ZnO-NPs showed the best antibacterial activity due to the largest surface area in comparison with spherical ZnO-NPs and rod-shaped ZnO-NPs, which promised the maximum Zn2+ release as bactericide mechanism that registered in the case of different ZnO-NPs morphologies.

scholarly journals Investigation on room temperature photoluminescence of pure and aluminum doped zinc oxide nanoparticles

2015 ◽  
Vol 33 (1) ◽  
pp. 205-212 ◽  
Author(s):  
N. Srinivasan ◽  
J.C. Kannan
Keyword(s):  
Zinc Oxide ◽  
Zinc Oxide Nanoparticles ◽  
Average Particle Size ◽  
Hexagonal Wurtzite Structure ◽  
Spectral Studies ◽  
Oxide Nanoparticles ◽  
Average Particle ◽  
Ir Studies ◽  
Aluminum Doped Zinc Oxide ◽  
Ft Ir

AbstractPure and aluminum doped zinc oxide nanoparticles were prepared by soft chemical method. The prepared nanoparticles were characterized by XRD, SEM-EDAX, UV-Vis, PL and FT-IR studies. XRD patterns revealed that the nanoparticles were crystallized in hexagonal wurtzite structure with an average particle size of 19 nm to 26 nm. The surface morphology was explored using SEM micrographs. The incorporation of aluminum was confirmed by EDAX and FT-IR studies. The band gaps of the particles were found from 3.48 eV to 3.53 eV through UV-Vis spectral studies. The defect related mechanism was investigated using PL measurements. The chemical functional groups in FT-IR spectra proved the formation of pure and aluminum doped zinc oxide nanoparticles.

Inducing the magnetic character in reduced graphene oxide through incorporation of Fe2O3 nanoparticles

2017 ◽  
Vol 31 (15) ◽  
pp. 1750118 ◽  
Author(s):  
Abdur Rauf ◽  
Syed Sohail Ahmad Shah ◽  
Sobia Allah Rakha ◽  
Munazza Gul ◽  
Ishaq Ahmad ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Average Particle Size ◽  
Hybrid Structures ◽  
Average Particle ◽  
Multilayer Graphene ◽  
Magnetic Devices ◽  
Reduced Graphene ◽  
20 Nm

A chemical two-step approach based on solvothermal technique has been adopted to synthesize the reduced graphene oxide (rGO)/Fe2O3 hybrid materials. The rGO was prepurified by acidic treatment, followed by sensitization to attach the desired functional groups. The structural, compositional, morphological and magnetic analyzes of the prepared samples were carried out using various characterization techniques. The fabricated rGO/Fe2O3 heterostructures were confirmed by X-ray diffraction analysis and Fourier transform infrared spectroscopy. Raman spectroscopy evidenced the fabrication of multilayer graphene and scanning electron microscopy was carried out to study the morphology of the prepared samples. The average particle size of Fe2O3 nanoparticles (NPs) loaded on rGO was found to be [Formula: see text]20 nm, as was observed during transmission electron microscopy. Thermogravimetric analysis of rGO/Fe2O3 hybrid structures was performed to investigate their thermal behaviors. It was evidenced that the incorporation of Fe2O3 NPs into rGO enhanced its thermal stability. Vibrating sample magnetometry showed that ferromagnetic character was induced in rGO due to involvement of Fe2O3 NPs. The rGO/Fe2O3 hybrid structures can be considered as a competent material for fabrication of various magnetic devices.

scholarly journals Microwave solvothermal synthesis and characterization of manganese-doped ZnO nanoparticles

2016 ◽  
Vol 7 ◽  
pp. 721-732 ◽  
Author(s):  
Jacek Wojnarowicz ◽  
Roman Mukhovskyi ◽  
Elzbieta Pietrzykowska ◽  
Sylwia Kusnieruk ◽  
Jan Mizeracki ◽  
...  
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Solvothermal Synthesis ◽  
Web Application ◽  
Zinc Acetate Dihydrate ◽  
Average Particle Size ◽  
Average Particle ◽  
Sem Images

Mn-doped zinc oxide nanoparticles were prepared by using the microwave solvothermal synthesis (MSS) technique. The nanoparticles were produced from a solution of zinc acetate dihydrate and manganese(II) acetate tetrahydrate using ethylene glycol as solvent. The content of Mn2+ in Zn1− x Mn x O ranged from 1 to 25 mol %. The following properties of the nanostructures were investigated: skeleton density, specific surface area (SSA), phase purity (XRD), lattice parameters, dopant content, average particle size, crystallite size distribution, morphology. The average particle size of Zn1− x Mn x O was determined using Scherrer’s formula, the Nanopowder XRD Processor Demo web application and by converting the specific surface area results. X-ray diffraction of synthesized samples shows a single-phase wurtzite crystal structure of ZnO without any indication of additional phases. Spherical Zn1− x Mn x O particles were obtained with monocrystalline structure and average particle sizes from 17 to 30 nm depending on the content of dopant. SEM images showed an impact of the dopant concentration on the morphology of the nanoparticles.

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