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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
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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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Magnetically separable CeO2/CoFe2O4 heterojunction photocatalysts for dye degradation: characterization and mechanism
(2024-01-01)
Seeharaj, Panpailin
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Pasupong, Patchara
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Choojun, Kittisak
This study developed magnetically separable CeO<inf>2</inf>/CoFe<inf>2</inf>O<inf>4</inf> heterojunction photocatalysts for dye degradation to reduce water pollution. The CeO<inf>2</inf>/CoFe<inf>2</inf>O<inf>4</inf> nanocomposites with different CeO<inf>2</inf> ratios (10, 20, and 30 wt%) were prepared by a precipitation method. The nanocrystalline 20%CeO<inf>2</inf>/CoFe<inf>2</inf>O<inf>4</inf> photocatalyst with a surface area of 117 m2.g−1, E<inf>g</inf> 2.37 eV, and uniform distribution of quasi-spherical CeO<inf>2</inf> minor phase (cubic fluorite structure with particle size 3 ± 1 nm) throughout the distorted spherical CoFe<inf>2</inf>O<inf>4</inf> major phase (cubic spinel structure with particle size 9 ± 3 nm) showed the best photocatalytic performance for methylene blue (MB) degradation under UV light irradiation at the efficiency of 88.7% and the apparent rate constant (k) of 0.0138 min−1. The 20%CeO<inf>2</inf>/CoFe<inf>2</inf>O<inf>4</inf> photocatalyst had a good magnetic response and could be easily separated from the dye solution by applying an external magnetic field. The reusability test showed lower photodegradation efficiency due to the adsorption of residual MB dye on the photocatalyst surface. The formation of heterojunction at the interfaces of CeO<inf>2</inf>/CoFe<inf>2</inf>O<inf>4</inf> facilitated the photogenerated charge separation and increased availability of active species of holes (h+) and hydroxy radicals (∙OH), which were the key factors in improving the photocatalytic activity.
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Multi Self-cleaning Properties of Zinc Oxide Nanoparticles/ Polydimethylsiloxane (ZnO/PDMS) Composite on Polyester Textile
(2023-03-02)
Wirunchit, Supamas
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Wonganan, Narin
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Koetniyom, Wantana
Self-cleaning textiles can be divided into three categories, which are the physical, chemical, and biological self-cleaning types. Physical self-cleaning refers to the lotus effect, which relates to the hydrophobic properties of the textile. Chemical self-cleaning is the degradation of color stains, discolored solutions and other organic species that come into contact with textiles. The last is biological self-cleaning, which is the ability to kill bacteria that become attached to the textiles. In this research, the development of all three self-cleaning properties of polyester textile coated with zinc oxide nanoparticles/ polydimethylsiloxane (ZnO/ PDMS) composite was focused. The ZnO nanoparticles were synthesized by a hydrothermal process, which involved blending PDMS with various concentrations of ZnO nanoparticles. The polyester textile was coated with ZnO/ PDMS composite solution via a dip coating technique done with various dipping times. The lotus effect, which depends on hydrophobic properties, was analyzed by water contact angle measurement. The chemical self-cleaning of the polyester textile was examined by photocatalytic methylene blue dye degradation with UV-Vis spectrometry. The inhibition zone of antibacterial activity was tested via disc diffusion technique. From these results, it was found that the polyester textile coated with ZnO/PDMS composite demonstrated all self-cleaning properties, physical, chemical and biological, in a significantly way.
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Effects of Hydroxypropyl Methylcellulose Fiber Amounts and Aspect Ratios on Properties of Biodegradable Composites Prepared from Thermoplastic Starch
(2023-01-01)
Pitpisutkul, Vipawan
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Jamjumras, Trisana
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Sawasdee, Kancharut
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Prachayawarakorn, Jutarat
Because of the low tensile properties and high hydrophilicity of thermoplastic starch (TPS), this research was focused on improving its characteristics through the addition of the natural cellulose fiber, hydroxypropyl methylcellulose (HPMC). Different TPS composites reinforced with HPMC fibers were compounded using an internal mixer and were shaped using a compression molding machine. The effects of HPMC fiber content and aspect ratios were examined. It was found from infrared spectra that the wavenumbers of the O-H stretching of TPS polymer clearly shifted to lower wavenumber with the incorporation of HPMC fibers, which indicated new hydrogen bond formation. Moreover, a significant increase of maximum stress and elastic modulus of TPS/ HPMC fiber composites was detected. A clear drop in moisture uptake was also found when HPMC fibers were added into the TPS polymer matrix. In addition, scanning electron microscopy and thermogravimetric analysis were used to characterize several TPS composites. Biodegradability for various composites was also determined.
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EFFECT OF h-BN AS AN ADDITIVE ON PHYSICAL AND MECHANICAL PROPERTIES OF Al2TiO5 COMPOSITE
(2023-01-01)
Treetornkeerati, Paramapat
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Hankoy, Montree
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Kitiwan, Mettaya
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Rodchom, Mana
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Vichaphund, Supawan
Aluminum titanate (Al<inf>2</inf>TiO<inf>5</inf>) is a promising material for high-temperature applications due to its low thermal expansion, high melting point, and excellent corrosion resistance. In this study, the effect of h-BN addition on the properties of Al<inf>2</inf>TiO<inf>5</inf> composites was investigated. The composites were prepared by sintering a mixture of Al<inf>2</inf>O<inf>3</inf> and TiO<inf>2</inf> at a 1:1 molar ratio, with varying amounts of h-BN (5-20 mol%) added to the mixture. The samples were sintered at 1,500ºC for 4 h in N<inf>2</inf> atmosphere, and the bulk density, porosity, phase transition, microstructure, flexural strength, and hardness of the composites were investigated. XRD analysis confirmed the presence of Al<inf>2</inf>TiO<inf>5</inf>, Al<inf>2</inf>O<inf>3</inf>, and Al<inf>18</inf>B<inf>4</inf>O<inf>33</inf> phases in the composites. The addition of h-BN in increasing amounts from 5 to 20 mol% resulted in a gradual improvement in the bulk density, flexural strength, and hardness of the Al<inf>2</inf>TiO<inf>5</inf> composites. The composite with the highest h-BN content (20 mol%) exhibited a bulk density of 3.12 g/cm3, as well as the highest flexural strength and hardness values of 123.6±8.9 MPa and 11.2±4.1 GPa, respectively.
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Recycling of Broken Waste Glass as Polyethylene Nanofiller for Electrical Insulating System
(2022-01-01)
Vittayakorn, W.
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Khunna, D.
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Buaphuen, P.
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Vittayakorn, N.
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Makcharoen, W.
This work focuses on the preparation of a high-quality glass powder from the broken windowpane. The expected glass powder must show a high amount of silicon dioxide with fine particle size. The processing technique used in this work is coarse grinding and high-speed vibratory milling under a variety of conditions to get the best quality of glass powder. The particle size and particle size distribution were examined by using DLS technique. The chemical composition was examined by EDX together with FT-IR and XRF spectroscopies. The results showed that the wide range of particle size distribution occurred in all milling conditions, which approximately ranged from 0.3 to 7 µm, and the 270 min-milling time showed the smallest particle size of glass powder. The chemical analysis showed that the glass powder is rich in silica which contained about 70.47% of SiO<inf>2</inf>. After that, the various ratios of the glass powder/HDPE composites were formed by using the traditional casting method. The physical and electrical properties were investigated for all composites. The results showed that after adding glass powder into the HDPE matrix, the ε<inf>r</inf> value significantly drops due to the inorganic filler suppressed polarization within the systems. For the resistivity, the ρ value significantly increases after adding glass powder to the HDPE matrix for all compositions because this filler promotes the hinder of electric current flow. Finally, it can conclude that the waste glass powder can use as a filler in the HDPE-based composite as better as the commercial SiO<inf>2</inf> powder for the electrical insulting application.
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CeO2/CuO/TiO2heterojunction photocatalysts for conversion of CO2to ethanol
(2021-09-10)
Seeharaj, Panpailin
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Vittayakorn, Naratip
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Morris, John
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Kim-Lohsoontorn, Pattaraporn
An attempt to reduce CO2 emissions has led to the development of CeO2/CuO/TiO2 heterojunction photocatalysts for photoconversion of CO2 to useful products, e.g. ethanol. Composite photocatalysts were simply prepared by mixing TiO2 (P25) with different mass ratios of CeO2 (1 wt%) and CuO (2 or 3 wt%) by ball milling. The prepared photocatalysts had uniformly distributed CeO2 and CuO phases, throughout the TiO2 phase. The integration of CeO2 and CuO into TiO2 at 1 wt% CeO2 and 3 wt% CuO produced a composite, with a reduced band gap of 2.88 eV, allowing absorption of lower energy light and a lower electron-hole recombination rate. The 1%CeO2/3%CuO/TiO2 photocatalysts yielded ethanol at 30.5 μmol gcat-1 h-1, almost three times higher than the yield from pure TiO2. This improved CO2 conversion efficiency was due to contributions from properties of both additives: CeO2 increased light absorption, while CuO acted as an electron trap and enhanced CO2 adsorption. In addition, the heterojunction at the interfaces facilitated the photogenerated charge separation, which, in turn, increased the charge participation in the catalyzed conversion reactions.
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Utilization of Waste Glass Powder as a Filler in Epoxy Resin Based Composite
(2021-01-01)
Buaphuen, P.
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Khunna, D.
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Vittayakorn, W.
This work focuses on the preparation of a high-quality glass powder from broken household waste glass. The expected glass powder prepared from household waste must show a high amount of silicon dioxide with fine particle size. The processing technique used in this work is coarse grinding and high-speed vibratory milling under a variety of conditions to get the best quality of glass powder. The particle size and particle size distribution were examined by using DLS technique. The chemical composition was examined by EDX together with FT-IR and XRF spectroscopies. The morphology of all glass powders was investigated by SEM. The results showed that the wide range of particle size distribution occurred in all milling conditions, which approximately ranged from 1 to 10 µm, and the 4 h-milling time showed the smallest particle size of glass powder. The chemical analysis showed that the glass powder was rich in silica which contained about 67% of SiO<inf>2</inf>. After that, the various ratios of the glass powder/epoxy resin composites were formed by using the traditional casting method. The physical, mechanical and electrical properties were investigated for all composites. The results showed that the H<inf>v</inf> value of the glass powder/epoxy resin composites exhibited a much higher value than that of pure epoxy resin. For the electrical properties, after added 1 wt% of glass powder into the matrix, the ε<inf>r</inf> and R significantly increased. The E<inf>b</inf> value of the composite prepared from waste glass powder showed no significant difference from the composite prepared from commercial SiO<inf>2</inf>. So, it can say that the waste glass powder can be used as a filler in the epoxy resin-based composite as well as the commercial SiO<inf>2</inf> powder for the electrical insulting application.

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