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 91

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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 Fe<sup>3+</sup> ions. © (2013) Trans Tech Publications, Switzerland.
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Growth of ZnO nano-rods and its photoconductive characteristics on the photo-catalytic properties
(2019-01-01)
Worasawat, Suchada
;
Tasaki, Katsuyoshi
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Hatanaka, Yoshinori
;
Neo, Yoichiro
;
Mimura, Hidenori
Zinc oxide (ZnO) nano-rods has widely been investigated as a promising material for photo-catalysis, due to its high photocatalytic activity for the ambient gas molecules. Well-aligned ZnO nano-rods arrays were obtained by the two steps growth. Firstly, seeding layer deposition by RF magnetron sputtering, and secondly, nano-rods growth by hydrothermal processes were investigated. Moreover, after the samples were annealed at 450 ºC, these samples were compared in crystalline characteristics and photo-electronic characteristics. The morphology of grown ZnO nano-rods were observed as the hexagonal nano-rods and XRD shows a (002) orientation in wurtzite crystals structure. Annealing processes shows a remarkable improvement of crystallinity. PL measurements showed a steep band edge emission and broad defect states emission and also fairly improvement in crystalline properties by the annealing process. The photoconductivity measurement could lead to investigate the photo-catalytic phenomena on the surface of ZnO nano-rods against the environmental gas molecules. The annealed samples showed a higher photo-conductivity and surface activity for the oxygen gas molecules comparing to the as grown samples.
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Investigation of structural properties of CuPc/TiO2 nanocomposites
(2010-02-05)
Saributr, Chaloempol
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Makprasat, Wanichaya
;
Thanomngam, Pitiporn
;
Pecharapa, Wisanu
Structural properties of hybrid nanocomposites based on TiO<inf>2</inf> nanostructures and Copper phthalocyanine (CuPc) were investigated. The composites were prepared by mixing TiO<inf>2</inf> nanoparticle (TNP) and nanotube (TNT) with CuPc suspension. The precipitated composites were obtained by centrifuged and dried processes. Structural properties of the composites were evaluated by mean of Raman Spectroscopy and X-ray Absorption Fine Structure (XAFS). The results implied that CuPc has interatomic distance of C atoms in the second shell are decreased when CuPc is in the hybrid composites. © (2010) Trans Tech Publications.
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Growth and characterization of Ni3FeN thin films by reactive gas timing RF magnetron sputtering
(2010-05-05)
Techitdheera, Wicharn
;
Thassana, Chewa
;
Pecharapa, Wisanu
;
Nukaew, Jiti
Ni<inf>3</inf>FeN films were deposited on the glass substrate at room temperature by reactive gas timing rf magnetron sputtering, with two conditions: (1) a time period of Ar:N<inf>2</inf> gas (2) a flow rate of Ar:N<inf>2</inf> gas. Our results show that sputter rate increase with increasing of a time period and the rate of Ar:N<inf>2</inf> gas. The crystal structure of thin films was investigated by x-ray diffraction show fcc structure of Ni<inf>3</inf>FeN (200) plane. The lattice constants increase with increasing of the flow rate of the nitrogen gas but it decrease with increasing of a time period of Ar gas. The grain size of thin films were investigated by atomic force microscope show the size range between 20-120 nm. ©2010 IEEE.
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Influence of hydrothermal time on structural properties of ZnO nanorods grown on spin-coated ZnO seeding layer
(2019-12-16)
Mahamu, Hambalee
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Srinonate, Wuttichai
;
Pecharapa, Wisanu
Most of the recent nanodevices are fabricated by using high-efficiency deposition methods and patterned via high-resolution lithography. However, there are drawbacks for the methods including small-scale product, high cost consumption, and multi-step processes. To reduce these disadvantages, this work focuses on the usage of sol-gel synthesis and spin coating method to fabricate ZnO seed layer onto glass substrates. All of substrates were patterned by conventional UV photolithography at exposure time of 7 seconds, then ZnO nanorods were hydrothermally grown at 90°C for 2, 3, and 4 hours, respectively. All of samples were characterised by scanning electron microscope (SEM) which revealed the sharp and smooth tip hexagonal structure at different hydrothermal time. The evolution of the nanorods' growth was investigated, and the diameters were estimated. Moreover, crystal quality was revealed by X-ray diffractograms. It was clear that the domination of c-axis plane occurred for all the samples associates with the crystallinity of the nanostructures. This indicated escalating of the non-monodirectional growth plane in increasing nanorods' diameter as the nanorods are polycrystal. Furthermore, the optical properties of the samples were observed by UV-visible spectroscopy and photoluminescence technique (PL). UV-visible spectroscopic data showed diminishing of the energy band gap when the diameter grew up. PL data revealed the reduction of the intensity ratio at near-band-edge peak versus oxygen vacancy peak. This information pointed to the decreasing trend of the crystal quality with escalating growth time.
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Synthesis and characterization of ZnO nanorods by hydrothermal method
(2018-01-01)
Worasawat, Suchada
;
Masuzawa, Tomoaki
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Hatanaka, Yoshinori
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Neo, Yoichiro
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Mimura, Hidenori
Hydrogen generation through solar-driven photoelectrolysis of water is a promising technology for clean power supply. Zinc oxide (ZnO) is often applied to a photoelectrochemical (PEC) cells for water splitting, because ZnO has a favorable band edge that straddles the redox potential of photoelectrolysis in water. In addition, formation of ZnO nanostructure is attracting much attention, since the efficiency of PEC cell largely depends on a surface area of contacts. Here we report a modified hydrothermal method to prepare ZnOnanorods, whose structures can be controlled by changing preparation parameters. Our method includes seeding process by simple dip-coating technique, followed by post annealing process and hydrothermal growth process of ZnO nanostructures. The morphology of the grown ZnO depended on the concentration of the solvent used to form the seed layer formation, post-annealing temperature, and growth temperature. At the seed layer solvent concentration of 0.2 M, the ZnOnanorods were needle-like. At 0.9 M, hexagonal ZnOnanorods were obtained. We have successfully prepared hexagonalZnOnanorods by varying seed layer concentration at 0.9M, annealed at 150 ºC for 2 h and grown at 120 ºC for 1 h.
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Characterization of Sol-gel derived Ti-doped tungsten oxide electrochromic thin films
(2011-01-01)
Paipitak, K.
;
Kahattha, C.
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Techitdheera, W.
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Porntheeraphat, S.
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Pecharapa, W.
Ti-doped WO<inf>3</inf> electrochromic thin films were deposited onto F-doped tin oxide (FTO) substrates using spin coating technique. The as-deposited films prepared with various concentration of titanium were annealed in air at 500°C. The effect of Ti-doping concentration on structural, surface morphology and optical properties of the films were characterized by X-ray diffractometer, scanning electron microscope and UV-VIS spectrophotometer. The results show that the crystalline of WO<inf>3</inf> can be identified at 2θ values of 24.14° corresponding to 200 orientation. In addition, It was found that the electrochromic performance of WO<inf>3</inf> can be enhanced by small doping concentration of titanium due to structural modification of the films. © 2011 Published by Elsevier Ltd.
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Sonochemical synthesis and characterization of copper oxide nanoparticles
(2011-01-01)
Wongpisutpaisan, Narongdet
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Charoonsuk, Piyanut
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Vittayakorn, Naratip
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Pecharapa, Wisanu
Copper oxide (CuO) nanoparticles were synthesized by a sonochemical process using copper nitrate and sodium hydroxide in the presence of polyvinyl alcohol (PVA) as a starting precursor. The precipitated product was calcined at various temperature ranging from 400-700°C. The physical microstructure and morphology of as-calcined nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). From XRD observation, it is evident that the high purity CuO nanoparticles were obtained by this synthesis process. It was additionally revealed that its crystallization and particle size was strongly dependent on the reaction time and calcination temperature. © 2011 Published by Elsevier Ltd.
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Magnetoelectric properties of BaTiO3 - Co0.5Ni0.5Fe2o4 composites prepared by the conventional mixed oxide method
(2013-10-29)
Pulphol, Nattakarn
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Muanglua, Rangson
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Niemcharoen, Surasak
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Pecharapa, Wisanu
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Vittayakorn, Wanwilai C.
Multiferroics, which display simultaneous ferrimagnetic and ferroelectric properties, have been interesting recently because of their potentially significant applications in multifunctional devices such as magnetic resonance, drug delivery, high-density data storage, ferrofluid technology, etc. Composites combining BaTiO<inf>3</inf> with Co<inf>0.5</inf>Ni<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> have influenced the interest of many researchers, due to their outstanding and distinguished character called magnetoelectric (ME). In this work, ferrimagnetic-ferroelectric composites of BaTiO<inf>3</inf> nanopowder and Co<inf>0.5</inf>Ni<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf> nanopowders were prepared by a conventional mixed oxide method. The multiferroic ceramics were compounded with the formula, (1-x)BaTiO<inf>3-</inf>(x) Co<inf>0.5</inf>Ni<inf>0.5</inf>Fe<inf>2</inf>O<inf>4</inf>, in which x = 0, 0.05, 0.10, 0.20 and 0.35. All of the compositions were analyzed by an X-ray diffractometer (XRD) in order to reveal the phase of perovskite and spinal structure. Scanning electron microscopy (SEM) was used to examine the variation of morphology and grain size of the composited ceramics. The magnetism of all the ceramics was measured using a vibrating sample magnetometer (VSM). The results showed that microstructure and the amount of ferrite are related strongly with magnetization. © (2013) Trans Tech Publications, Switzerland.
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Physical properties of Ti-doped ITO nanoparticles synthesized by co-precipitation method
(2016-04-26)
Chongsri, K.
;
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.

Pecharapa, Wisanu

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