Synthesis of ZnO nanostructures by hydrothermal method (original) (raw)
Related papers
Journal of Ceramic Science and Technology
A low-temperature hydrothermal method was used to prepare ZnO nano-microparticles using surfactant-free solutions. The effect of the alkali concentration (Zn 2+ /OH-= 1:1, 1:2, 1:4 and 1:8) and reaction time (1, 2 and 3 hours) on the morphology of the ZnO was studied. The structure and the morphology of the ZnO obtained were investigated by means of XRD and SEM techniques, respectively. The results revealed that the solution basicity and reaction time were important factors affecting the morphology. With an increase in the reaction time, the crystallinity of the phases formed was enhanced. At a low alkali concentration, i.e. 1:1, a ZnO hexagonal prism-like structure with a crystal size of 300 nm-1.5 lm and Zn(OH) 2 amorphous phase were formed. With a further increase to Zn 2+ /OH-=1:2, some nanorods and flakes appeared beside the ZnO nanoparticles. When the ratio reached Zn 2+ /OH-= 1:4, different morphologies such as nanorods, slices and nanoflakes were obtained. At Zn 2+ /OH-= 1:8, the morphology changed into microflowers as the major structure with some nanoparticles and nanosheets as the minor structure.
Journal of Nanomaterials, 2011
We investigated the influence of the pH value, precursor concentration (C), growth time and temperature on the morphology of zinc oxide (ZnO) nanostructures. The pH of the starting solution was varied from 1.8 to 12.5. It was found that the final pH reaches an inherent value of 6.6 independently of the initial pH solution. Various ZnO structures of nanotetrapod-like, flower-like, and urchin-like morphology were obtained at alkaline pH (8 to 12.5) whereas for pH solution lower than 8 rod-like nanostructures occurred. Moreover, we observed the erosion of the nanorods for a pH value less than 4.6. By changing the concentrations the density and size were also varied. On going from a high (C>400 mM) to lower (C<25 mM)C, the resulted ZnO nanostructures change from a film to nanorods (NRs) and finally nanowires (NWs). It was also found that the length and diameter of ZnO NRs follow a linear relation with time up to 10 hours, above which no further increase was observed. Finally the e...
Makara Journal of Science, 2018
Micro-nanorod structures of zinc oxide (ZnO) have been successfully synthesized via a simple and low-cost hydrothermal method. ZnO solutions with different concentrations of 0.05 and 0.1 M were prepared using zinc nitrate tetrahydrate and hexamethylenetetramine precursors. They were dissolved in aquades and stirred before the hydrothermal process at 95 C for 4 hours in an oven. Extensive characterizations using scanning electron microscope (SEM) and Xray diffraction (XRD) were conducted on ZnO powder samples. SEM results showed that hexagonally shaped ZnO micro-nanorods were formed with diameters ranging from hundreds of nanometers to several micrometers. The ZnO sample synthesized at 0.05 M was observed to have a better surface morphological structure than the 0.1 M sample. In addition, XRD measurements confirmed that samples exhibited a hexagonal crystal structure of ZnO. Moreover, the calculated crystallite sizes of ZnO using the Debye-Scherrer equation using the full-width half maxima of the XRD peaks were 25.153 nm for the 0.05 M sample and 28.707 nm for the 0.1 M sample. The most prominent growth of ZnO had 101 plane orientation or nonpolar a-plane followed by nonpolar 100 m-plane and 002 polar c-plane orientations. This study offers a simple and low-cost route to produce high-quality ZnO micro-nanorods for use in various electrical and optical devices. Abstrak Kajian Morfologi dan Struktural Batang Mikro-nano ZnO Disintesis Menggunakan Metode Hidrotermal dengan Biaya Rendah. Struktur batang mikro-nano seng oksida (ZnO) berhasil disintesis menggunakan metode hidrotermal sederhana dan dengan biaya yang rendah. Larutan ZnO dengan konsentrasi berbeda yaitu 0,05 dan 0,1 M disiapkan menggunakan prekursor seng nitrat tetrahidrat dan heksamethilentetramin. Prekursor tersebut dilarutkan di dalam akuades dan diaduk sebelum proses hidrotermal berlangsung pada suhu 95 C selama 4 jam di dalam oven. Sampel serbuk ZnO dikarakterisasi secara ekstensif menggunakan mikroskop elektron (SEM) dan difraksi sinar-x (XRD). Hasil analisis SEM menunjukkan bahwa batang mikro-nano ZnO berbentuk heksagonal dihasilkan dengan rentang diameter dari ratusan nanometer hingga beberapa mikrometer. Sampel ZnO yang disintesis dengan konsentrasi 0,05 M teramati memiliki struktur morfologi yang lebih baik dibandingkan sampel 0,1 M. Pengukuran XRD mengkonfirmasi bahwa sampel sesuai dengan ZnO dengan struktur kristal heksagonal. Lebih lanjut, perhitungan estimasi rata-rata ukuran kristal ZnO menggunakan persamaan Debye-Scherrer dengan puncak XRD lebar penuh pada setengah maksimum didapat yaitu sebesar 25,153 nm untuk sampel 0,05 M dan 28,707 nm untuk sampel 0,1 M. Pertumbuhan ZnO paling dominan yaitu pada orientasi bidang 101 atau bidang nonpolar a diikuti orientasi bidang nonpolar m 100 dan bidang polar c 002. Kajian ini menawarkan metode yang simpel dan dengan biaya rendah untuk menghasilkan batang mikronano ZnO yang memiliki potensi untuk diaplikasikan dalam berbagai peralatan elektronik dan optik.
RESEARCH NOTE CONTROLLABLE SYNTHESIS OF FLOWER-LIKE ZnO NANOSTRUCTURE WITH HYDROTHERMAL METHOD
Abstract Flower-like ZnO nanostructures were synthesized by decomposing Zn (OH) 2 in 1, 4-butanediol at 105 C for 36 h. Size of flower-like ZnO nanostructure can be controlled by pH of the aqueous solution. In the preparation of flower-like ZnO nanostructure, zinc nitrate was used as a precursor. The morphology and microstructure of flower-like ZnO nanostructure have been characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy.
Controllable Synthesis of Flower-Like Zno Nanostructure with Hydrothermal Method (Research Note)
International Journal of Engineering-Transactions B: Applications, 2009
Flower-like ZnO nanostructures were synthesized by decomposing Zn (OH) 2 in 1, 4-butanediol at 105 C for 36 h. Size of flower-like ZnO nanostructure can be controlled by pH of the aqueous solution. In the preparation of flower-like ZnO nanostructure, zinc nitrate was used as a precursor. The morphology and microstructure of flower-like ZnO nanostructure have been characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. The synthesized flower-like ZnO ...
ZnO nanoparticles obtained by hydrothermal method at low temperature
2008
The structural properties and morphology of ZnO nanoparticles obtained by hydrothermal method were studied. ZnO samples were obtained by hydrothermal method, in soft synthesis conditions, temperature of solution about 70°C, in presence of a bidentate ligand or a tensioactive agent. The resulted oxides morphologies were compared with the morphologies of ZnO samples obtained in absence of ligands or tensioactive agents. Samples present a hexagonal phase of ZnO with lattice parameters about a=0.32nm and c=0.5nm, values confirmed by XRD measurements. Morphological properties are studied using bright field images, measuring the nanoparticles diameter and nanopellets size.
Materials Letters, 2013
Specific flower shaped ZnO crystals with well defined morphologies have been synthesized via hydrothermal method using zinc acetate dihydrate and sodium hydroxide as starting materials. Also soluble starch was used as a stabilizer and crystallization controller in alkaline medium. Scanning electron microscopy studies suggested that keeping all experimental parameters constant the morphology of ZnO crystals could be easily changed in the presence of starch. The analyses of the crystal structures and the morphologies of flower shaped ZnO were carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with EDS. A mechanism for the formation of different morphologies is proposed.
HYDROTHERMAL SYNTHESIS OF ROD AND CHRYSANTHEMUM LIKE NANOSTRUCTURED ZnO
Indonesian Journal of Chemistry, 2011
thin film have been prepared hydrothermally in NaOH and NH 3 solution utilizing zinc nitrate hexahydrate as the precursor. ZnO thin films were grown on ITO glass substrate with the seed layer of zinc oxide. Perpendicularly aligned arrays of corrugated ZnO nanorods were grown in NaOH solution, while the chrysanthemum like structure was obtained in ammonia solution. X-Ray diffraction patterns confirmed that both morphologies presenting wurtzite crystal of ZnO. The nanorod showed strong (002) orientation of ZnO.
Controlling the Morphology of ZnO Nanostructures in a Low-Temperature Hydrothermal Process
The Journal of Physical Chemistry B, 2005
ZnO nanostructures of different morphologies were grown in a controlled manner using a simple low-temperature hydrothermal technique. Controlling the content of ethylenediamine (soft surfactant) and the pH of the reaction mixture, nanoparticles, nanorods, and flowerlike ZnO structures could be synthesized at temperatures 80-100°C with excellent reproducibility. High-resolution electron microscopy revealed the well crystalline nature of all the nanostructures with preferential growth along the [002] direction for linear structures. Photoluminescence spectra of the as-grown nanostructures revealed oxygen-vacancy-related defects in them, which could be reduced by air annealing at 250°C. Possible mechanisms for the variation of morphology with synthesis parameters are discussed.
Preparation of various morphologies of ZnO nanostructure through wet chemical methods
Advanced Material Science, 2019
Hydrothermal route and solution reaction method are adopted for the synthesis of zinc oxide (ZnO) nanopowders having four different morphologies such as nanoparticle, mirorod, nanoplate and nanotubule. Zinc nitrate hexahydrate Zn(NO 3) 2 .6H 2 O was used as precursor for ZnO nanostructures. ZnO nanorods and nanoplates were synthesized by a hydrothermal approach using KOH as reaction chemical. ZnO nanotubes were obtained by a chemical reaction of Zn(NO 3) 2 and NH 4 OH. And ZnO nanoparticles were prepared by precipitation method from zinc nitrate and ammonium carbonate (NH 4) 2 CO 3 in aqueous solution. The structures, morphology, and element components of these ZnO products fabricated by the above-mentioned methods were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). These experimental results demonstrated that the as-prepared ZnO nanoparticles have average diameter of 30-60 nm; rod-like ZnO has average diameter of about 350 nm and the length of 3.5 µm; plate-like ZnO has average thickness of about 40 nm and lateral size of 200 × 400 nm; ZnO nanotubules have outer diameter of about 400 nm and inner diameter of about 300 nm, the length of about 4 µm. The XRD results indicated that four morphologies of ZnO are all wurtzite structure. It is found that the wet chemical technique is very promising for fabricating ZnO nanocrystallines with various morphologies.