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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X-ray absorption spectroscopy analysis and magnetic properties of M-doped TiO2 nanoparticles (M=Co, Mn, Ni and Zn) prepared by co-precipitation method
(2017-08-01)
Wattanawikkam, Chakkaphan
;
Pecharapa, Wisanu
;
Ishihara, Keiichi N.
M-doped TiO<inf>2</inf> nanoparticles (M=Co, Mn, Ni and Zn) were synthesized by co-precipitation method combined with annealing at 500 °C for 2 h. X-ray diffraction (XRD) was used to identify their structural phases. X-ray absorption near edge structure (XANES) was conducted to probe the chemical state and crystal atomic structure of prepared samples. Magnetic properties of all samples were characterized by vibrating sample magnetrometer (VSM). The XRD analyses reveal that all samples crystallize in anatase tetragonal structure with no additional peaks. The XANES spectra exhibit triple pre-edge fingerprint of Ti4+ of oxidation state with six-fold octahedral coordinate structure. Co-, Ni- and Zn- K-edge results indicate that the Co, Ni and Zn ions in M-doped TiO<inf>2</inf> are in 2+ formal oxidation state. Meanwhile, Mn-doped TiO<inf>2</inf> sample contains the different oxidation states of 3+ and 4+. The amount of each oxidation state is confirmed by using linear combination fitting method. The magnetic measurement illustrates the paramagnetic behavior for Co-, Mn- and Ni- doped samples that strongly depend on the doping content and no hysteresis loop is observed in undoped and Zn-doped samples.
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Sonochemical Synthesis, Characterization, and Photocatalytic Activity of Perovskite ZnTiO3 Nanopowders
(2016-10-01)
Wattanawikkam, Chakkaphan
;
Pecharapa, Wisanu
Perovskite zinc titanate (ZnTiO<inf>3</inf>) nanopowders were synthesized using the sonochemical method combined with calcinations at 500 °C and 900 °C for 2 h to improve their crystallinity. The effect of calcination temperature on their structural, optical, and photocatalytic properties has been studied. The cubic phase and the mixing phase of cubic and hexagonal were observed in sample calcined at 600 °C and 700 °C, respectively, while the spinel ZnTiO<inf>3</inf> and rutile TiO<inf>2</inf> phase arises in sample calcined over 700 °C. The valence state was investigated by the X-ray absorption near-edge spectroscopy technique, and the corresponding results indicate the existence of Zn2+ and Ti4+ in the powders. The chemical states of the samples were scrutinized by X-ray photoelectron spectroscopy. The average particle size is approximately 20-240 nm. The excellent photocatalytic performance of ZnTiO<inf>3</inf> nanoparticle calcined at 700 °C gave complete degradation Rhodamine B (RhB) in 75 min under ultraviolet light exposure with the k rate of 0.033 min-1 and 55% of decolorization RhB in 210 min under visible irradiation. The sample calcined at 700 °C ensures a good dielectric permittivity with a value 20 and the loss tangent of about 10-2.
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Characterization, X-ray absorption spectroscopic analysis and photocatalytic activity of Co/Zn co-doped TiO2 nanoparticles synthesized by one-step sonochemical process
(2021-10-01)
Mekprasart, Wanichaya
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Pavasupree, Sorapong
;
Jayasankar, C. K.
;
Ravuri, Balaji Rao
;
Wattanawikkam, Chakkaphan
A novel one-step preparation of sonochemical method was applied to synthesize Co/Zn co-doped TiO<inf>2</inf> nanoparticles using a sonicator of 750 W, 20 kHz for 30 min at room temperature. The formation of the anatase TiO<inf>2</inf> phase for all as-prepared samples was observed from XRD results with a crystalline size in nanoscale. The use of ultrasound allowed for the successful doping of both Co and Zn into the TiO<inf>2</inf> lattice, which was confirmed by Synchrotron light including X-ray near edge structure (XANES) and Extended X-ray absorption fine structure (EXAFS) spectroscopy. Ti K-edge, Co K-edge, and Zn K-edge XANES spectra exhibited the dominating +4, +2, and +2 valence state of Ti, Co, and Zn in as-prepared samples, respectively. A detailed XANES and EXAFS data analysis give strong evidence that the Co/Zn dopants partially replace the Ti atom of the TiO<inf>2</inf> host. The Co/Zn co-doping extends the light absorption of the host to the visible region and restricts the e+/h+ recombination. The photocatalytic activity of samples was tested for degradation of Rhodamine B dye solution under visible light irradiation. The as-synthesized of the co-doped catalyst was presented as highly efficient, with 2.5 and 5 times dye degradation compared with single-doped and bare TiO<inf>2</inf>.
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Enhanced photocatalytic ability of CuO/Ni-doped TiO2 nanocomposite under visible light: Theory and experiment
(2025-09-01)
Bootchanont, Atipong
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Samerchue, Sorravich
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Sipae, Chanapong
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Zhao, Huali
;
Noonuruk, Russameeruk
CuO/Ni-doped TiO<inf>2</inf> composite photocatalysts were synthesized using a co-precipitation method as the composite of Ni-doped TiO<inf>2</inf> (Ni–TiO<inf>2</inf>) with 0.5, 1.0, and 1.5 mol% of CuO. Composites with different CuO/Ni–TiO<inf>2</inf> ratios were studied to assess the influence of Ni and CuO on the crystal and local structure by X-ray diffraction (XRD) and X-ray absorption (XAS). The energy bandgap is investigated by UV–visible spectroscopy and is described by computational calculations using density functional theory (DFT). The correlation between the local site of Ni and the band structure will be analyzed and discussed by comparing the experiment and First-principle calculations. The photocatalytic activity of the CuO/Ni–TiO<inf>2</inf> systems is due to the absorption of radiation in the visible light region. The results indicated that 1.5 mol% of CuO contributes to the Ni–TiO<inf>2</inf> nanoparticles showing highest photocatalytic activity with rate constant of 0.03477 min−1 in the degradation of Rhodamine B, which could be attributed to the low recombination rate of the electron-hole pair, and decrease of the bandgap, increase in the concentration of •OH radicals in the solution, which is beneficial for improving the photo degradation rate of organic compounds.
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Synergistic effects of biomass-derived carbon quantum dots and Cu Co-doping on TiO2 nanocomposite for enhanced visible-light photocatalysis
(2026-12-01)
Zhao, Huali
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Noonuruk, Russameeruk
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Bootchanont, Atipong
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Porjai, Porramain
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Thongpool, Voranuch
The development of sustainable approaches for enhancing the visible-light activity of TiO<inf>2</inf>-based photocatalysts has attracted considerable research interest. In this work, carbon quantum dots (CQDs)-Cu co-modified TiO<inf>2</inf> nanocomposites were synthesized via a hydrothermal method using butterfly pea ( Clitoria ternatea ) flowers as a biomass-derived carbon source. The Cu content was fixed at 1.5 mol% relative to Ti, while the CQDs loading was controlled by varying the butterfly pea precursor concentration from 0.25 to 1.25 g L−1, yielding 1C–Cu–TiO<inf>2</inf>, 3C–Cu–TiO<inf>2</inf>, and 5C–Cu–TiO<inf>2</inf> samples. The prepared materials were characterized by electron microscopy, X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy, photoluminescence (PL), and X-ray absorption spectroscopy (XAS). High-resolution transmission electron microscopy revealed CQDs with an average size of approximately 4.29 nm and an interplanar spacing of approximately 0.23 nm. All composites retained the anatase TiO<inf>2</inf> phase after Cu incorporation and CQDs modification. Enhanced visible-light absorption was observed and is attributed to the formation of Cu-related sub-band-gap states and the sensitization effect of CQDs. PL analysis showed an emission peak at ∼415 nm under 660 nm excitation, suggesting the presence of upconversion photoluminescence behavior in the CQDs. Conventional PL spectra further suggested reduced charge-carrier recombination in the modified composites. Photocatalytic activity was evaluated through Rhodamine B (RhB) degradation under visible-light irradiation. Among all samples, 1C–Cu–TiO<inf>2</inf> exhibited the highest performance, achieving degradation efficiency of 99.28% within 50 min. The apparent reaction rate constant reached 0.1038 min−1, which was 2.23, 1.96, and 2.90 times higher than those of pristine TiO<inf>2</inf>, Cu–TiO<inf>2</inf>, and 3C–Cu–TiO<inf>2</inf>, respectively. Radical scavenging experiments indicated that •OH and h+ were the dominant reactive species, while •O<inf>2</inf>− also participated in the degradation process. The enhanced photocatalytic performance is attributed to the synergistic effects of Cu and biomass-derived CQDs in improving visible-light harvesting and charge separation, providing an effective approach for developing visible-light-responsive TiO<inf>2</inf> photocatalysts.
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Piezoelectric enhanced photocatalytic properties of PVDF–ZnO/Cu nanofibers prepared by electrospinning technique
(2022-01-01)
Bootchanont, Atipong
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Porjai, Porramain
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Noonuruk, Russameeruk
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Wattanawikkam, Chakkaphan
;
Pavasupree, Sorapong
Piezoelectric-assisted photocatalysis technology is one of the efficient ways to achieve enhancement in photocatalytic performance by facilitating the separation of photoinduced electron and holes via internal field initiated via piezoelectricity. Herein, bi-piezoelectric integrated effect was generated by the combination of piezoelectric semiconductor photocatalyst ZnO/Cu and piezoelectric polymer polyvinylidene fluoride (PVDF). Firstly, ZnO/Cu nanoparticles were prepared by facile co-precipitation method. Then, nanoparticles (at 10–30 wt%) were loaded in PVDF for fabricating nanofibers by electrospinning technique. All PVDF–ZnO/Cu nanofibers were characterized by XRD, FE-SEM, FTIR, XAS, and UV–Vis DRS. The structural study indicates that the β- and α-phase PVDF is observed in all the prepared nanofibers. XANES technique confirms the oxidation state of 2+ for Zn and Cu ions in both nanoparticles and nanofibers. Furthermore, under the synergy action of ultrasonic and visible light irradiation, PVDF–ZnO/Cu nanofibers exhibit superior piezo-photocatalytic degradation of rhodamine B dye when compared with single light or mechanical excitation. Effects of ZnO/Cu concentration on optical, piezoelectric, and photocatalytic properties are discussed.
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Optical, dielectric and photocatalytic properties of perovskite ZnTiO3 nanoparticle synthesized by sonochemical process
(2015-07-29)
Wattanawikkam, Chakkaphan
;
Pecharapa, Wisanu
The sonochemical method was employed for synthesizing perovskite zinc titanate nanopowders. The yield powders were calcined at 600-900 °C for 2 h. High crystallinity phase of cubic ZnTiO<inf>3</inf> was obtained at calcination temperature of 600 °C while mixing phase of cubic and hexagonal was observed in the sample calcined at 700 °C. For the samples calcined at 800 and 900 °C, the hexagonal structure was dominant phase with a trace of rutile TiO<inf>2</inf> and spinel Zn<inf>2</inf>TiO<inf>4</inf> phase. X-ray absorption near edge spectroscopy technique (XANES) was used to probe crystal and local structure of the synthesized powders. The samples calcined at 700 °C exhibited the superior photocatalytic performance in decolorization of Rhodamine B dye under ultraviolet irradiation within 75 min. The dielectric permittivity and loss tangent of ZnTiO<inf>3</inf> calcined at 700 °C was found to be 20 and <10-2. Effect of calcination temperature on structural, morphology, optical, dielectric properties and photocatalytic activity were also investigated and discussed.
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Effect of cobalt dopant on structural and optical properties of co-precipitated TiO2 nanopowders
(2016-01-01)
Junlabhut, Prasopporn
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Wattanawikkam, Chakkaphan
;
Phoohinkong, Weerachon
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Mekprasart, Wanichaya
;
Pecharapa, Wisanu
The effects of cobalt (Co) addition on structural and optical properties of TiO<inf>2</inf> nanopowders have been investigated. A co-precipitation method was employed to synthesize TiO<inf>2</inf> nanoparticles with various Co additives from 0-10 mol% using tetrabutyl titanate and Cobalt (II) nitrate hexahydrate as starting precursors for Ti and Co source, respectively. The crystallinity of Co-doped TiO<inf>2</inf> nanopowders is heightened by calcination process. The crystal structure, phase formation and the corresponding functional groups of Co-doped TiO2 were analyzed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The scanning electron microscope (SEM) was taken to observe their morphologies. The chemical compositions of Co additive into TiO<inf>2</inf> matrix are confirmed by EDAX. Their optical properties were investigated by diffuse reflectance spectroscopy. Diffuse reflectance spectra of samples exhibit the increasing absorption in visible region with an increasing Co content. The overall characterization results indicated that the crystallinity and optical properties of TiO<inf>2</inf> nanoparticles are significantly affected by Co dopant.
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Structural and photocatalytic properties and X-ray absorption spectroscopic study of BiVO4 nanoparticles incorporated with Fe synthesized by sonochemical method
(2022-11-01)
Wechprasit, Tirapat
;
Bootchanont, Atipong
;
Sailuam, Wutthigrai
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Wattanawikkam, Chakkaphan
;
Kansaard, Thanaphon
In this work, Fe-incorporated BiVO<inf>4</inf> nanoparticles with different Fe-loading contents (0–4%) were synthesized via one-step sonochemical process. Crystal structure of all samples was investigated by X-ray diffraction technique (XRD). XRD patterns obviously show the main structure of monoclinic BiVO<inf>4</inf> structure. The secondary phase is found in the form of Fe-based oxide as a hematite Fe<inf>2</inf>O<inf>3</inf> phase at for Fe-loading contents ≥ 2%. Relevant chemical bonding of as-synthesized samples was carried out by Raman spectroscopy indicating the fundamental vibration with various vibration modes of VO<inf>4</inf>3− tetrahedron and V–O band, respectively. Morphological structure of pure BiVO<inf>4</inf> shows rod-like structure while 1–4%Fe-incorporated BiVO<inf>4</inf> display different morphologies. The chemical compositions and oxidation numbers of all elements of the samples were carried out via X-ray photoelectron spectroscopy (XPS). XPS spectra indicate the existence of all elements on their surface and the oxidation states of all elements are clearly scrutinized. Local structure of all samples was investigated to interrogate the local atomic site of Fe atoms by X-ray absorption spectroscopy (XAS). The normalized Fe K-edge XANES spectra of all samples indicate that the local atomic site of Fe atoms would not replace in local sites of either Bi or V sites in BiVO<inf>4</inf> crystal verified by simulated XANES spectra. However, the specific features of measured XANES spectra of all samples corresponds to the Fe K-edge XANES spectra of Fe<inf>2</inf>O<inf>3</inf> and BiFeO<inf>3</inf> structure suggesting that local structure of all samples are formed to Fe-based oxide between Fe<inf>2</inf>O<inf>3</inf> and BiFeO<inf>3</inf> structure. Fitting EXAFS spectra of 1–4%Fe-incorporated were practically conducted by artemis program with Fe<inf>2</inf>O<inf>3</inf> and BiFeO<inf>3</inf> used as structural models to identify local atomic environment of Fe atoms. Results show agreeable fitting with their structural models and reveal pertinent information of localization of Fe atoms. Optical properties of the samples were analyzed by UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS). DRS results exhibit the absorption edge in visible range of all samples. Meanwhile, influence of Fe loading contents into pure BiVO<inf>4</inf> displays to confirm the red-shift on the absorption edge in visible range to higher wavelength, which suggests the lower optical band gap of pure BiVO<inf>4</inf>. The optimized photocatalytic degradation of RhB was performed by 4%Fe–BiVO<inf>4</inf> with 82% decolorization under visible-light irradiation within 10 min and exhibited rate constant at 0.150 min−1.
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X-ray absorption spectroscopy analysis and photocatalytic behavior of ZnTiO3 nanoparticles doped with Co and Mn synthesized by sonochemical method
(2019-04-30)
Wattanawikkam, Chakkaphan
;
Kansa-ard, Thanaphon
;
Pecharapa, Wisanu
ZnTiO<inf>3</inf> (ZTO) as a perovskite structure doped with Co and Mn were fabricated by sonochemical process. Structural phase, chemical and local atomic structure and photocatalytic activity of the synthesized samples were characterized, by X-ray diffraction, by X-ray absorption spectroscopy and Rhodamine B (RhB) dye degradation. The XRD results revealed that the mixing phases of cubic and hexagonal zinc titanate phases were found in all samples. The X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure technique (EXAFS) have been used to identify the crystal and atomic local structure of prepared samples. The Fourier transform EXAFS results of these prepared samples agreed well with the model of Co and Mn substituting at the B-site of ABO<inf>3</inf> structure together with small cluster of CoO and Mn<inf>2</inf>O<inf>3</inf> cluster. The photocatalytic activity for rhodamine b dye degradation under visible light irradiation exhibited that the doped samples had the superior degradation compared to bare-ZTO sample. The results suggest that the incorporation of transition metal ions of Co and Mn dopants is an effective way to improve the catalytic efficiency of perovskite ZTO structure. The effect of different dopant ions and dopant concentration on the structural, chemical, optical and photocatalytic activity are discussed.

Pecharapa, Wisanu

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