Pecharapa, Wisanu

Preferred name

Pecharapa, Wisanu

Alternative Name

PECHARAPA, Wisanu

Pecharapa, W.

Main Affiliation

Integrated Innovative Technology

wisanu.pe@kmitl.ac.th

Now showing 1 - 10 of 15

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Sol-gel combustion synthesis and characterizations of nanocrystalline Zinc, Nickel and Nickel-Zinc ferrites
(2013-10-29)
Tangcharoen, Thanit
;
Ruangphanit, Anucha
;
Klysubun, Wantana
;
Pecharapa, Wisanu
In this work, X-ray diffraction (XRD), Raman spectroscopy (RAMAN) and vibrating sample magnetometer (VSM) measurements were employed to investigate the crystal structure, chemical bonding and magnetic properties of the nanocrystalline Zinc, Nickel and Nickel-Zinc ferrites (ZnFe<inf>2</inf>O<inf>4</inf>, NiFe<inf>2</inf>O<inf>4</inf> and Ni<inf>0.5</inf>Zn<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf>) which were synthesized by sol-gel combustion method. Moreover, the composition of elements and the electronic structure including the cation distribution for all ferrite samples were examined through synchrotron X-ray fluorescence (XRF) and X-ray absorption near-edge structure (XANES) spectra. The overall characterization results indicate that the different amount of zinc and nickel ions in ferrites has crucial effect on their physical, magnetism and the site occupancy distribution of Fe3+ ions. © (2013) Trans Tech Publications, Switzerland.
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A comparison of cation distribution and valence state in spinel crystal structure of zinc and nickel ferrites using the synchrotron X-ray absorption spectroscopy (XAS) analysis
(2014-07-24)
Tangcharoen, Thanit
;
Klysubun, Wantana
;
Ruangphanit, Anucha
;
Pecharapa, Wisanu
In this work, the physical structure, magnetism and local structure of zinc and nickel ferrites (ZnFe<inf>2</inf>O<inf>4</inf> and NiFe<inf>2</inf>O <inf>4</inf>) synthesized by typical sol-gel combustion method, were investigated by X-ray diffraction (XRD), vibrating sample magnetometer (VSM), X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). The formation of the single phase cubic spinel crystal structure and the different values of crystallite size (D), interplanar distance (d) and lattice constant (a) for all ferrite samples were evaluated by the XRD data. The VSM measurement provides the characteristic magnetic hysteresis loop (M-H) for each sample which was found to be significantly different from each other. The chemical shifts in Zn, Ni and Fe K-edges XANES spectra indicate the existence of Zn2+, Ni2+ and Fe3+ ions in these ferrites. The EXAFS spectra analyses applied to track Zn, Ni and Fe cation distribution indicate the distinct character of spinel crystal structure of both ferrites. The results exhibit that zinc ferrite is a normal spinel, while the nickel ferrite is an inverse spinel. Moreover, these EXAFS spectra analyses reveal that the distances between metal ion (Zn2+ or Ni2+) to central oxygen ion and to Fe3+ ions in the opposite lattice site for each ferrite sample are unequal which highly affect its magnetism. The overall simulated results are one of the important evidence encouraging the explanation on the paramagnetism for ZnFe<inf>2</inf>O<inf>4</inf> and the ferrimagnetism for NiFe<inf>2</inf>O<inf>4</inf>. © 2014 Taylor & Francis Group, LLC.
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Synthesis, characterization and multiferroic properties of Ni 0.5Zn0.5Fe2O4-K0.5Na 0.5NbO3 nanocomposites
(2013-01-01)
Tangcharoen, Thanit
;
Ruangphanit, Anucha
;
Klysubun, Wantana
;
Pecharapa, Wisanu
In this work, nanocrystalline lead-free multiferroic composites of nickel zinc ferrite (Ni<inf>0.5</inf>Zn<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf>) - potassium sodium niobate (K<inf>0.5</inf>Na<inf>0.5</inf>NbO<inf>3</inf>) were synthesized by a sol-gel combustion method. The influence of Ni <inf>0.5</inf>Zn<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> content, on the crystal structure, chemical bonding, morphologies, dielectric properties and magnetic behavior of K<inf>0.5</inf>Na<inf>0.5</inf>NbO<inf>3</inf> was investigated using X-ray diffraction measurement, Raman spectroscopy, scanning electron microscope, LCR meter and vibrating sample magnetometer, respectively. The overall characterization results indicate that the various contents of ferrite and ferroelectric materials in those composites have a significant influence on their multiferroic properties. In addition, this method is proven as one of an ordinary, fast and efficacious way to synthesize functional multiferroic materials with simple availability implements. © 2013 Copyright Taylor and Francis Group, LLC.
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Synchrotron X-ray absorption spectroscopy and magnetic characteristics studies of metal ferrites (metal = Ni, Mn, Cu) synthesized by sol-gel auto-combustion method
(2014-01-01)
Tangcharoen, Thanit
;
Klysubun, Wantana
;
Kongmark, Chanapa
;
Pecharapa, Wisanu
In this work, the metal ferrites MFe<inf>2</inf>O<inf>4</inf> (M = Ni, Mn, Cu) were synthesized from metal nitrate precursors by the sol-gel auto-combustion method using diethanolamine (DEA) as a potential fuel. The crystal structures of these ferrite powders were characterized by X-ray diffraction (XRD) technique confirming the complete formation of the single-phase cubic spinel crystal structure. The ferrimagnetism characteristic and the difference of the magnetic properties such as saturation magnetization (M<inf>s</inf>), remanent magnetization (M<inf>r</inf>), and coercivity (H <inf>c</inf>) for each after-calcined ferrite sample were scrutinized through the ferrimagnetic hysteresis loop (M-H) obtained from the vibrating sample magnetometer (VSM) measurement. Moreover, the cation distribution and valence state of these ferrites were investigated by the Ni, Mn, Cu, and Fe K-edge X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectra using the synchrotron radiation light source. From the XAS results, the analyses of both XANES and EXAFS spectra show the existence of accurate oxidation state for transition metal ions and the interionic distance to the nearest neighbors in the spinel crystal structure. In particular, the curve-fitting analysis of Ni, Mn, Cu, and Fe K-edge EXAFS spectra indicates that the degree of inversion in these metal ferrites is entirely different and found to be 0.2 for MnFe<inf>2</inf>O<inf>4</inf>, 0.8 for CuFe<inf>2</inf>O <inf>4</inf>, and 1.0 for NiFe<inf>2</inf>O<inf>4</inf>, which are the important information for understanding their effects on relevant magnetic properties. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Effect of Zn:Al ratio and calcination time on structural properties of Zn-Al-O compound
(2016-01-01)
Mekprasart, Wanichaya
;
Worasawat, Suchada
;
Tangcharoen, Thanit
;
Pecharapa, Wisanu
Zn-Al-O compounds were successfully synthesized via co-precipitation method at pH 8 followed by calcination process at 900 °C. Influence of different precursor (Zn:Al) ratio and calcination time on their structural properties and formation have been investigated. Varying Zn:Al ratio was conducted at 2:1, 1:1, 1:2 and 1:4 with different calcination time at 0, 2, 4, and 6 h. Phase transformation and morphologies were characterized by X-ray diffraction and field-emission scanning electron microscope. Moreover, chemical bonding of Zn-Al-O compound was analyzed by Raman spectroscopy. The results indicated that chemical bonding between Zn-Al oxide evidentially occurred in all samples in composite form and spinel structure. In addition, the amount of Al content considerably contributes to significant aggregation in zinc aluminate (ZnAl<inf>2</inf>O<inf>4</inf>) spinel crystalline phase affirmed by XRD result. Meanwhile, SEM images reveal high crystallinity and strong formation of the compound obtained by prolong calcined period.
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Synchrotron X-ray absorption spectroscopy study of disordered cation distribution of nanosized zinc ferrite powders
(2016-01-01)
Tangcharoen, Thanit
;
Kongmark, Chanapa
;
Klysubun, Wantana
;
Pecharapa, Wisanu
The zinc ferrite (ZnFe<inf>2</inf>O<inf>4</inf>) powders of various nanoparticle sizes were synthesised at different milling times (0 to 24 h) of the as-combusted powders. The non-equilibrium site occupancy of zinc (Zn2+) and ferric (Fe3+) ions was investigated through Zn and Fe K-edge X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectra. The XRD and SEM strongly confirm the particle size of these ferrites decreasing with the increasing milling time. Compared with the bulk specimen of zinc ferrite, both XANES and EXAFS spectra of zinc ferrite powders clearly exhibit the large translocation of Zn2+ ions from the tetrahedral (A) sites to the octahedral (B) sites and the opposite translocation of some of Fe3+ ions without affecting the long-range structural order. Moreover, the curve-fitting analysis of Zn and Fe K-edge EXAFS spectra indicates that the degree of inversion increases as the particle size decreases resulting in significant differences in the magnetic behaviours.
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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
;
Worasawat, Suchada
;
Tangcharoen, Thanit
;
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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Synthesis and characterization of cubic-like zinc stannate powders prepared by co-precipitation method
(2016-01-01)
Mekprasart, Wanichaya
;
Tangcharoen, Thanit
;
Nakhanivej, Puritat
;
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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Modification of dye-sensitized solar cell working electrode using TiO 2 nanoparticle/N-doped TiO2 nanofiber composites
(2014-01-01)
Mekprasart, Wanichaya
;
Suphankij, Sineenart
;
Tangcharoen, Thanit
;
Simpraditpan, Athapon
;
Pecharapa, Wisanu
Nanocomposite films of N-doped TiO<inf>2</inf> nanofibers (NFs) and commercial-grade TiO<inf>2</inf> nanoparticles Degussa (P25) were utilized as working electrode of typical dye-sensitized solar cells (DSSCs). N-doped TiO<inf>2</inf> NFs were fabricated via electrospinning method using ammonium acetate (CH<inf>3</inf>COONH<inf>4</inf>) as nitrogen source and titanium (IV) isopropoxide (TiP) in ethanol as starting precursor in combination with calcinations process. The electrospun NFs were characterized by XRD, Raman spectroscopy, XPS, SEM, and TEM. The photoelectric conversion performance of the DSSCs with composite film electrode was compared to the device using pure P25 film. The result shows that as calcination temperature increases, the anatase-to-rutile phase transformation and the fiber size reduction of NFs were observed. The energy conversion efficiency (η) of the device tends to increase with increasing calcined temperature with specific nanofiber loading content, indicating the significant enhancement in the device performance by the incorporation of the NFs. This enhancement of DSSCs may attribute to high surface area, higher light scattering and light harvesting, low charge recombination, and fast electron-transfer rate by loaded NFs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Characterization and enhanced photocatalytic performance of nanocrystalline Ni-substituted Zn ferrites synthesized by DEA-assisted sol-gel auto-combustion method
(2013-06-01)
Tangcharoen, Thanit
;
Ruangphanit, Anucha
;
Klysubun, Wantana
;
Pecharapa, Wisanu
Nanocrystalline Ni-substituted Zn ferrites with compositions of Ni <inf>x</inf>Zn<inf>1-x</inf>Fe<inf>2</inf>O<inf>4</inf> (x = 0-1.0) were synthesized by sol-gel auto-combustion method using metal nitrate as the reactants. Diethanolamine was selected as the fuel instead of conventional fuels such as urea, citric acid, tartaric acid or glycine. Characterization of after-calcined ferrite samples were conducted in terms of crystal structure, molecular vibrations, morphology and magnetic properties through X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope and vibrating sample magnetometer analysis, respectively. The photocatalytic activities of these ferrites were studied in term of degradation of Rhodamine B under daylight-irradiation. The corresponding results indicate that nickel loading content has significant effect on physical, magnetic, optical and photocatalytic properties of the ferrite. Comparing to the undoped Zn ferrite, Ni<inf>0.6</inf>Zn<inf>0.4</inf>Fe<inf>2</inf>O<inf>4</inf> shows the enhancement in photocatalytic activity accompanying the degradation of Rhodamine B aqueous solution up to 77 % within 4 h. The result suggests the feasibility of this material as potential sunlight-activated photocatalyst in wastewater treatment and environment cleaning applications. © 2013 Springer Science+Business Media New York.

Pecharapa, Wisanu

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