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 152

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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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Microwave-assisted synthesis of ZnO/MWCNT hybrid nanocomposites and their alcohol-sensing properties
(2014-01-01)
Potirak, Prayut
;
Pecharapa, Wisanu
;
Techitdheera, Wichan
Zinc oxide and multi-walled carbon nanotube (ZnO/MWCNT) hybrid nanocomposites were synthesised by microwave-assisted method using the mixed solution of zinc acetate dehydrate (Zn(CH<inf>3</inf>COO)<inf>2</inf>·2H<inf>2</inf>O) and treated MWCNTs. The syntheses were carried out at various microwave irradiation powers. The characterisation of the as-synthesised nanocomposites was conducted by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD results revealed that the composites were composed of two phases of MWCNTs and hexagonal wurzite ZnO. The SEM results showed that the ZnO nanoparticles were well decorated on the surface of MWCNTs. The amount of ZnO nanoparticles and their size increased with increasing irradiation power. Thick-film sensors were fabricated onto interdigitated conducting electrodes using as-synthesised hybrid composites as sensing materials. The alcohol-sensing behaviour of the hybrid composite films was investigated. The results indicated that the irradiation power had significant influence on the sensing response of the sensors toward alcohol. The sensor fabricated from the composite synthesised at higher irradiation power exhibited an enhanced alcohol-sensing performance. © 2013 Taylor & Francis.
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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
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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
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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
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Thassana, Chewa
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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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Effect of nitrogen doping on optical and photocatalytic properties of TiO2 thin film prepared by spin coating process
(2013-01-01)
Mekprasart, Wanichaya
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Khumtong, Thanakorn
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Rattanarak, Jiravat
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Techitdheera, Wicharn
;
Pecharapa, Wisanu
Nitrogen-doped TiO<inf>2</inf> thin films were prepared by spin coating on glass substrate. Different amount of nitrogen doped in TiO<inf>2</inf> matrix was 0, 3 and 10%. As-obtained films were annealed at 400°C for 2 h. The optical and photocatalytic properties of N-doped TiO<inf>2</inf> thin films were analyzed via UV-Vis spectrophotometry. The chemical properties were investigated by Fourier transform infrared spectrometer and Raman spectroscopy. When doping TiO<inf>2</inf> with nitrogen, its absorption spectrum is shifted to visible region resulting to the enhancement of photocatalyst properties in dye photodegradation. Raman and FTIR patterns show that N-doped TiO<inf>2</inf> pattern is still identical to undoped TiO<inf>2</inf> pattern resulting to unsubstitutation of nitrogen atom in Ti-O bonding. © 2013 The Authors.
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Characterization and x-ray absorption spectroscopy of ilmenite nanoparticles derived from natural ilmenite ore via acidassisted mechanical ball-milling process
(2017-09-01)
Phoohinkong, Weerachon
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Pavasupree, Sorapong
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Wannagon, Anucha
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Sanguanpak, Samunya
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Boonyarattanakalin, Kanokthip
In this work activated ilmenite nanoparticles were prepared by chemical-assisted in mechanical ball-milling process from ilmenite ore as starting raw material. The effect of milling process on their phase composition, particle size, surface morphology and local structure were investigated. Phase identification and crystalline structure of ilmenite mineral, milled samples and subsequent leached residues were characterized by x-ray diffraction (XRD). Meanwhile, the distorted octahedral structure and the oxidation state of relevant elements in ilmenite ore and activated ilmenite obtained by different process conditions were analyzed by x-ray absorption spectroscopy (XAS). Particle size and morphologies of the samples were monitored by field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM). Three dominant peaks of TiO2 rutile, FeTiO<inf>3</inf>, and Fe<inf>2</inf>TiO<inf>4</inf> are obviously adulterated in XRD patterns after mechanical milling with water and acid solution when comparing to precursor mineral. However, the contaminated phase of FeTiO3 and Fe<inf>2</inf>TiO<inf>4</inf> was readily decreased by acid-assisted mechanical ball-milling. The enhancement in leaching process of ilmenite residue after milling can be obtained with sulfuric acid. This result suggests that iron contaminated phase could be leached from the sample resulting to the decrease in Fe environment around Ti atom.
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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
;
Neo, Yoichiro
;
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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Preface
(2017-01-01)
Nukeaw, Jiti
;
Pecharapa, Wisanu
;
Yimnirun, Rattikorn
;
Ishihara, Keiichi N.

Pecharapa, Wisanu

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