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Comparative study of post-sintering temperature on properties of copper doped zinc oxide nanoparticles prepared by co-precipitation process
(2017-01-01)
Chaithanatkun, Natpasit
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Onlaor, Korakot
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Tunhoo, Benchapol
Copper doped zinc oxide nanoparticles (Cu doped ZnO NPs) has been prepared by co-precipitation process using zinc nitrate, copper nitrate and potassium hydroxide as zinc, copper and hydroxide precursor, respectively. All of prepared conditions were fixed as the concentration of copper in zinc oxide about atomic percentage at 2%. The prepared powders of Cu doped ZnO NPs were studied with various post-sintering temperature at 500, 600 and 700 °C. All of samples were characterized using X-ray Diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FT-IR). The EDX spectra showed the qualitative and quantitative elemental composition of prepared material, meanwhile, XRD peaks represented Cu doped ZnO NPs in hexagonal wurtzite structure. The improvement in crystallinity of Cu doped ZnO NPs could be performed by sintering process. Moreover, the SEM and TEM images showed that the Cu doped ZnO NPs were condensed to the larger particles size by the increase of sintering temperature. Finally, the FT-IR spectra showed a broad absorption band for all of samples.
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Physical properties of Ti-doped ITO nanoparticles synthesized by co-precipitation method
(2016-04-26)
Chongsri, K.
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Kanoksinwuttipong, J.
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Techitdheera, W.
;
Pecharapa, W.
Ti-doped indium tin oxide (ITO) nanoparticles (TITO) with different molar ratios of Ti:ITO were synthesized by co-precipitation method using Ti(OCH2CH2CH2CH3)4, InCl3 and SnCl4·5H2O as starting precursors. Deionized (DI) water was selected as the solvent in this process. The as-precipitated powders were calcined at different temperature in range of 700 °C for 2 h. For all samples, their crystal structures, Optical property and morphologies were investigated by X-ray diffraction (XRD), UV-Vis absorption spectroscopy and Scanning electron microscope (SEM), respectively. XRD results reveal that the purity of as-synthesized sample is increased by the increase of calcination temperatures. Moreover, it is noticed that the incorporation of Ti into ITO matrix significantly affects to their relevant physical properties especially optical properties. In addition, SEM micrographs show that the sample agglomeration is noticeably influenced by Ti doping content.
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Structural and optical properties of F-doped ZnO nanoparticles synthesized by co-precipitation process
(2016-01-01)
Chongsri, Krisana
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Mekprasart, Wanichaya
;
Pecharapa, Wisanu
In this work, we reported the preparation of F-doped ZnO nanoparticles by facile precipitation process using zinc nitrate and ammonium fluoride as starting precursors for Zn and F, respectively dissolved in deionized water. The precursor solution was prepared at various fluoride composition ranging from 1-5 wt%. The as-precipitated powders were calcined at different temperature from 500 °C to 700 °C for 2 h. Effect of calcination temperature and fluoride concentration on structural, morphologies, optical and electrical properties were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis spectroscopy, respectively. XRD results indicated the complete formation of hexagonal wurtzite structure of ZnO. SEM micrographs showed the agglomeration for each sample that noticeably influenced by fluoride content.
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Synthesis and characterization of cubic-like zinc stannate powders prepared by co-precipitation method
(2016-01-01)
Mekprasart, Wanichaya
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Tangcharoen, Thanit
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Nakhanivej, Puritat
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Pecharapa, Wisanu
Spinel-type zinc stannate (Zn<inf>2</inf>SnO<inf>4</inf>) powders were synthesized by co-precipitation method using zinc chloride and tin chloride as the precursors for Zn and Sn sources, respectively. Co-precipitation process is one of effective techniques due to non-complex system, short process time, high yield, large scale production and cost-effectiveness comparing to other methods. The influence of calcination temperature in the range of 900 °C to 1100 °C on the structure, morphologies and cation distribution were studied using various characterization techniques. A single spinel structure phase formation after-calcined powders are confirmed by X-ray diffraction (XRD) results meanwhile scanning electron microscope (SEM) showed the appearance of cubic-like shape. The aggregation of particle and strong crystallinity was distinctly increased resulting to their greater size by the effect of high calcined temperature. Moreover, the non-equilibrium site occupancy of zinc (Zn2+) and tin (Sn4+) ions was investigated through Zn K-edge and Sn L3-edge investigated by X-ray absorption (XAS) spectra via the synchrotron radiation light source. Compared with the calcined temperature sample, XANES spectra revealed that the oxidation state of Zn was +2 and Sn valence was +4 in all spinel Zn<inf>2</inf>SnO<inf>4</inf> samples which well corresponds to the theoretical values.
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Characterisation of Ti-doped indium tin oxide nanoparticles synthesised by co-precipitation process
(2016-01-01)
Chongsri, K.
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Kanoksinwuttipong, J.
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Techitdheera, W.
;
Pecharapa, W.
Ti-doped indium tin oxide (ITO) nanoparticles (TITO) with different molar ratios of Ti:ITO were synthesised by co-precipitation method using Ti(OCH<inf>2</inf>CH<inf>2</inf>CH<inf>2</inf>CH<inf>3</inf>)<inf>4</inf>, InCl<inf>3</inf> and SnCl<inf>4</inf>·5H<inf>2</inf>O as starting precursors. Deionised (DI) water was selected as the solvent in this process. The as-precipitated powders were calcined at different temperatures around 700°C for 2 h. For all samples, their crystal structures, optical properties and morphologies were investigated by X-ray diffraction (XRD), UV-Vis absorption spectroscopy, scanning electron microscope (SEM), and transmission electron microscope (TEM), respectively. XRD results reveal that the purity of as-synthesised samples is increased with the increase of calcination temperatures. Relevant mechanisms involved in the synthesis via precipitation process are discussed. It is noticed that the incorporation of Ti into ITO matrix significantly affects the relevant physical properties and optical properties.
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Structural Properties of Ga-Doped ZnO Nanoparticles Synthesized by Co-Precipitation Process
(2015-09-02)
Chongsri, K.
;
Pecharapa, W.
Ga-doped ZnO (GZO) nanoparticles were synthesized by co-precipitation process from starting precursors zinc dichloride (ZnCl2) and Gallium (III) nitrate hydrate (GaN3O9). The deionized (DI) water was selected as the solvent. The as-precipitated powders were calcined at different temperature of 700 and 1000 °C for 2 h. For all samples, their crystal structures were investigated by X-ray diffraction (XRD) and surface morphologies were observed by a field emission scanning electron microscope (FE-SEM). The XRD results revealed that, the crystallinity of powders increases when the calcination temperature increases. Moreover, it is noticed that the intermixture phases of ZnO and Ga2O3 occur when the Ga doping content is exceeded the solubility limit of about 10%. In addition, SEM micrographs show the decrease of particle size with increasing Ga doping content due to lattice distortion that can hinder the crystal growth of ZnO. © 2015
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Characterization and effect of calcination temperature on structural properties of spinel zinc aluminate synthesized via Co-precipitation process
(2015-06-01)
Mekprasart, Wanichaya
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Worasawat, Suchada
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Tangcharoen, Thanit
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Pecharapa, Wisanu
Zinc aluminate (ZnAl<inf>2</inf>O<inf>4</inf>) nanopowders were synthesized by co-precipitation method using zinc chloride and aluminum chloride as starting precursors. The calcination temperature which was a crucial preparation factor was varied and its influence on relevant physical properties of the product was investigated. Structural properties of synthesized nanoparticles were investigated by X-ray diffraction, X-ray absorption spectroscopy, scanning electron microscope, and Raman spectroscopy. The results suggest that that ZnAl<inf>2</inf>O<inf>4</inf> in spinel structure with high crystallinity can be obtained after calcination beyond specific temperature affirmed by XRD results. Raman result indicates the correlated chemical bonding relating to the formation of ZnAl<inf>2</inf>O<inf>4</inf> structure. Meanwhile, the Zn K-edge X-ray absorption near-edge structure (XANES) spectra of these samples with different calcination temperature obtained from the synchrotron X-ray absorption spectroscopy measurement show the existence of accurate oxidation state for zinc ion (Zn2+) in the spinel crystal structure. Moreover, it is revealed that the calcination temperature has significant effect on the local environment of the zinc absorbing atoms through the interesting change of white line appearance.
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Physical and optical properties of indium oxide:tin nanoparticles synthesized by co-precipitation method
(2015-01-01)
Kanoksinwuttipong, Jiruntanin
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Pecharapa, Wisanu
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Noonuruk, Russameeruk
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Techitdheera, Wicharn
Indium oxide:tin nanoparticles were synthesized by co-precipitation method using InCl<inf>3</inf> and SnCl<inf>4</inf>·5H<inf>2</inf>O as starting precursor with different molar ratios of Sn:In. The crystalline structure, optical properties, chemical bonding and morphologies of all samples were characterized by X-ray diffraction (XRD), UV-vis spectrometer, Raman spectroscopy and field emission scanning electron microscope, respectively. The XRD results show that the crystallinity of as-synthesized powders was initially amorphous phase. After calcination at 400 °C for 2 h, a single phase ITO powder with 10% (mol%) SnO<inf>2</inf> was obtained. The particle size of each sample is approximately 20-25 nm. The color of indium oxide:tin nanopowders after heat treatment changed from white to yellow due to the substitution of oxygen vacancies in the sample. After calcination, the intensity of Raman peak significantly decreased with increasing amount of Sn loading. This phenomenon indicates that ion substitution may occur during the synthesis process. Moreover, it is noticed that the optical absorbance of obviously changed with increasing Sn loading.
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Structural, optical and photo catalytic properties of Cu-doped ZnO nanoparticles synthesised by co-precipitation method
(2014-01-01)
Thaweesaeng, N.
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Suphankij, S.
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Techitdheera, W.
;
Pecharapa, W.
In this work, co-precipitation method was utilised to synthesise Cu-doped ZnO nanoparticles using zinc nitrate (Zn(NO<inf>3</inf>)2·6H <inf>2</inf>O), and copper(II) nitrate trihydrate (Cu(NO<inf>3</inf>)2·3 H<inf>2</inf>O) as starting precursors for Zn and Cu sources, respectively. Structural and physical properties of as-prepared powders were examined by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS) and X-ray absorption near edge spectroscopy (XANES). The XRD results reveal that Cu-doped ZnO nanopowders are in hexagonal wurtzite structure and their crystallinity deteriorates with increasing Cu doping content. FTIR results additionally show the existence of relevant chemical bonding in the samples. Meanwhile, XPS and XANES results indicate the existence of Cu ion with relevant electronic state in ZnO. Optical properties of the samples were investigated and the corresponding results suggest that Cu additive plays a crucial role in their optical properties that can be adjusted to meet the requirement for practical solar energy harvesting applications such as sun-light photocatalyst. The photocatalytic activity of as-prepared Cu-doped ZnO photocatalyst was investigated by the degradation of Rhodamine B solution. The catalyst with 6% Cu doping content exhibits the enhancement in photocatalytic activity with reaction rate of 0.0267 min-1. The significant improvement in photocatalytic activity of the doped sample may be associated to the increase of functional hydroxyl radicals due to the incorporation of specific content Cu dopant. Copyright © 2014 Inderscience Enterprises Ltd.
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Effect of tin loading on physical properties and phase transformation of as-synthesized Zn-Sn-O compound powder synthesized by co-precipitation method
(2014-01-01)
Kahattha, C.
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Chongsri, K.
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Noonuruk, R.
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Mekprasart, W.
;
Pecharapa, W.
Zinc-Tin oxide compounds (Zn-Sn-O) were successfully prepared via a facile co-precipitation process using zinc dichloride dihydrate as the zinc source and tin tetrachloride pentahydrate as an additive source. The as-prepared product of Zn-Sn-O powders with various Sn additive contents (0-60 %wt) were obtained without calcinations process. The effect of Sn additive on structural and microstructure properties of the samples were characterized by X-ray diffraction(XRD), scanning electron microscope(SEM). The results indicate that the crystallinity and morphologies of ZnO nanoparticles are significantly influenced by Sn additive. The phase formations of Zn-Sn-O including ZnO, ZnSn(OH)<inf>6</inf> were observed depending on the Sn-additive composition.

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