Areerob, Yonrapach

Preferred name

Areerob, Yonrapach

Main Affiliation

School of Engineering

yonrapach.ar@kmitl.ac.th

Now showing 1 - 10 of 19

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Novel gamma-irradiated chitosan-doped reduced graphene-CuInS2 composites as counter electrodes for dye-sensitized solar cells
(2022-05-20)
Areerob, Yonrapach
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Hamontree, Chaowalit
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Sricharoen, Phitchan
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Limchoowong, Nunticha
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Laksee, Sakchai
To address the issues associated with traditional counter electrodes, a novel gamma-irradiated chitosan-doped reduced graphene-CuInS<inf>2</inf> composite (Chi@RGO-CIS) was used as the counter electrode (CE). The system was fabricated following a simple hydrothermal method. The prepared Chi@RGO-CIS was characterized by various spectroscopic and microscopic techniques. The synergistic effect between chitosan, CuInS<inf>2</inf>, and reduced graphene oxide can help in producing a large surface area. It can also help in the generation of catalytic sites toward I-/I<inf>3</inf>-redox electrolytes. We used a composite (based on electrical considerations) to study the effect of the amount of graphene on the characteristics and photovoltaic efficiency of the Chi@RGO-CIS composites. The solar cell assembled with 1.5% Chi@RGO-CIS exhibited an efficiency of 12.21%. The efficiency was higher than that of a Pt-based device (9.96%) fabricated under the same conditions. Hence, Chi@RGO-CIS can be potentially used as the CE of dye-sensitized solar cells (DSSCs). It can be used as a substitute for Pt in DSSCs.
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Remodelling hierarchical NiCo2O4@ZnS nanorods with multi-walled carbon nanotubes as a counter electrode for dye-sensitized solar cell applications
(2026-12-01)
Nukunudompanich, Methawee
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Nachaithong, Theeranuch
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Phumuen, Phatcharin
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Wannabut, Wassana
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Kunbuala, Neeraphat
A hierarchical NiCo<inf>2</inf>O<inf>4</inf>@ZnS/MWCNT (NCO@Z-MWCNTs) nanocomposite was synthesized to serve as a platinum-free counter electrode for dye-sensitized solar cells (DSSCs). The nanocomposite comprised spinel NiCo<inf>2</inf>O<inf>4</inf> nanorods, ZnS associated with the surface of the nanorods, and an interconnected multi-walled carbon nanotube (MWCNT) network, and it was synthesized via a low-temperature solution-based hydrothermal method. XRD confirmed the presence of cubic NiCo<inf>2</inf>O<inf>4</inf> and zinc blende ZnS phases, while FESEM–EDS and XPS analyses verified the incorporation of ZnS and the formation of a conductive carbon framework interconnecting adjacent nanorods. ZnS, rather than acting as an isolated catalytic component, was considered to contribute additional sulfide-related surface sites and to modulate the interfacial electronic environment of the NiCo<inf>2</inf>O<inf>4</inf> nanorods, which likely facilitated redox reactions involving the I−/I<inf>3</inf>− couple. Meanwhile, the MWCNT network established continuous electron transport pathways, effectively reducing interfacial resistance and enhancing charge-transfer efficiency. Thermogravimetric and electrochemical analyses revealed enhanced thermal stability, improved redox kinetics, and a significant reduction in charge-transfer resistance compared with pristine NiCo<inf>2</inf>O<inf>4</inf>.The optimized NCO@Z–MWCNT 9wt% counter electrode achieved a power conversion efficiency of 10.03% under AM 1.5 G illumination, exceeding that of the Pt reference device (9.6%). Overall, the improved performance was attributed to the combined contributions of ZnS surface modification and the conductive MWCNT network, which together enhanced charge transport and electrocatalytic activity. This work demonstrates a scalable strategy for developing cost-effective, durable, and high-performance counter electrodes for dye-sensitized solar cells.
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Selective Fe(ii)-fluorescence sensor with validated two-consecutive working range using N,S,I-GQDs associated with garlic extract as an auxiliary green chelating agent
(2022-05-12)
Pimsin, Nipaporn
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Keawprom, Chayanee
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Areerob, Yonrapach
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Limchoowong, Nunticha
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Sricharoen, Phitchan
The goal of this work was to use the pyrolysis process to synthesize graphene quantum dots doped with garlic extract (as N,S-GQDs) and simultaneously co-doped with iodine (as I-GQDs). XPS, HR-TEM, FE-SEM/EDX, FT-IR, fluorescence, and UV-visible absorption spectroscopy were used to characterize the N,S,I-GQDs and analyze their morphological images. The quantum yield of N,S,I-GQDs was found to be 45%, greater than that of undoped GQDs (31%). When stimulated at 363 nm, the N,S,I-GQDs display a strong fluorescence intensity at a maximum wavelength of 454 nm. Using N,S,I-GQDs as a fluorescence quenching sensor for screening tests with various metal ions, it was discovered that they are extremely selective towards Fe2+ over Fe3+ and other ions. Thus, solution pH, concentration of N,S,I-GQDs, quantity of garlic extract, EDTA and AgNO<inf>3</inf> concentration as masking agents, reaction duration under ultrasonic aid, and tolerable limit of Fe3+ presence in the target analyte were all optimized for Fe2+ detection. A highly sensitive detection of Fe2+ was obtained using a linear curve with y = 141.34x + 5.5855, R2 = 0.9961, LOD = 0.11 mg L−1, and LOQ = 0.35 mg L−1. The method precision, given as RSDs, was determined to be satisfactory at 1.04% for intra-day analysis and 3.22% for inter-day analysis, respectively. As a result, the selective determination of trace amounts of Fe2+ in real water samples using such labile multi-element doped GQDs in conjunction with garlic extract as a green chelating agent to maintain its enhanced sensitivity was successfully applied with good recoveries ranging from 89.16 to 121.45%.
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Lithium Amount Effect of Li-Inserted Ultra-Surface Area-Activated Carbon and Improvement of the Electrochemical Performance with Magnetic Field for Li-Ion Capacitors
(2022-12-27)
Otgonbayar, Zambaga
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Areerob, Yonrapach
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Yang, Sunhye
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Kim, Ick Jun
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Oh, Won Chun
It is possible that controlling the lithium-ion amount may relate to the high energy and the specific capacitance of active materials into a single device. As the cathode for Li-ion capacitors (LICs) using nonaqueous electrolytes, we investigated surface functionalization of ultra-surface area-activated carbon (UAC) powder. An increase in capacitance was observed, from 1.25 × 104 to 8.10 × 104 F/g with controlling of lithium amount, as well as an increase in the area explicit capacitance per BET surface region from 657.57 to 1605.25 m2/g, which indicates that redox responses and their remarkable potential might enhance the capacitance for LICs. The pseudocapacitive redox reaction at C=O destinations is mostly attributed to capacitance enhancement. As with the improvement in capacitance, it was discovered that the arrangement of the electrolytes depends on the wetting behavior and particle size that can be adjusted. This study suggests the way for a low-cost and widely used UAC powder with controlling of lithium amount and a magnetic field for LICs. The 6LUAC samples treated with a magnetic field showed excellent specific capacity and energy density compared to samples not treated with a magnetic field under the same test conditions. Finally, we expect that this method may contribute to improvement of the electrochemical performance of materials.
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A comprehensive review and clinical guide to molecular and serological diagnostic tests and future development: In vitro diagnostic testing for COVID-19
(2023-01-01)
Areerob, Yonrapach
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Sagadevan, Suresh
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Oh, Won Chun
COVID-19 is a contagious syndrome caused by SARS Coronavirus 2 (SARS-CoV-2) that requires rapid diagnostic testing to identify and manage in the affected persons, characterize epidemiology, and promptly make public health decisions and manage the virus present in the affected person and promptly make public health decisions by characterizing the epidemiology. Technical problems, especially contamination occurring during manual real-time polymerase chain reaction (RT-PCR), can result in false-positive NAAT results. In some cases, RNA detection technology and antigen testing are alternatives to RT-PCR. Sequencing is vital for tracking the SARS-CoV-2 genome's evolution, while antibody testing is beneficial for epidemiology. SARS-CoV-2 testing can be made safer, faster, and easier without losing accuracy. Continued technological advancements, including smartphone integration, will help in the current epidemic and prepare for the next. Nanotechnology-enabled progress in the health sector has aided disease and pandemic management at an early stage. These nanotechnology-based analytical tools can be used to quickly diagnose COVID-19. The SPOT system is used to diagnose the coronavirus quickly, sensibly, accurately, and with portability. The SPOT assay consists of RT-LAMP, followed by pfAgo-based target sequence detection. In addition, SPOT system was used to detect both positive and negative SARS-CoV-2 samples. This combination of speed, precision, sensitivity, and mobility will allow for cost-effective and high-volume COVID-19 testing.
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A Novel Synthesis of Rod-Shape BaNiSn-Graphene Decorated TiO2 Composite as a Ternary Photocatalyst to Improve Visible-Light Driven H2 Evolution with Lactic Acid and TEA
(2023-03-01)
Areerob, Yonrapach
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Rafat, Md Nazmodduha
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Ullah, Kefayat
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Oh, Won Chun
A novel rod-shape BaNiSn-Graphene oxide decorated TiO<inf>2</inf> composite (BaNiSn-GT) has been synthesized using a simple ultrasonic method to enhance the visible-light-driven H<inf>2</inf> evolution with cationic scavengers. The unique structure between the interfaces of BaNiSn-Graphene and TiO<inf>2</inf> provides graphene oxide of contact and excellent electron transfer for H<inf>2</inf> evolution activity. The BaNiSn-GT ternary photocatalyst exhibits relatively high photocatalytic activity with a hydrogen evolution rate of 1012 μmol/g during 4 h. On the other hand, BaNiSn-GT composite exhibited significantly higher hydrogen evolution rates of 870 μmol/g with TEA scavenger and 730 μmol/g with LA scavenger during 1 h, respectively. Moreover, the higher photocurrent density of BaNiSn-GT is correlated with electron–hole recombination, providing evidence for its inhibition, which leads to a longer lifetime of carriers produced by photoelectrons. The mechanism of the photocatalytic H<inf>2</inf> evolution of BaNiSn-GT based on a full physicochemical characterization was proposed. This study provides new insight into the efficient hydrogen-evolution of graphene-based photocatalysts.
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Magnetic and ultrasonic integrated photocatalytic hydrogen evolution effects with Nanosize CoOCu2OZnO and TiO2 decorated on reduced graphene oxide
(2023-12-01)
Areerob, Yonrapach
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Meng, Zeda
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Ullah, Kefayat
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Wijaya, Karna
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Otgonbayar, Zambaga
In this study, metal oxide composite (CoOCu<inf>2</inf>OZnO) and TiO<inf>2</inf> on graphene oxide composite (CCZ−G−T) were synthesized to improve visible light-driven H<inf>2</inf> evolution through the addition of a cation scavenger, ultrasonic effect, and magnetic field effect. The synthesized nanocomposites were characterized through structural, surface, and electrochemical analyses with band structure. The photocatalyst showed hydrogen production of 792 μmol·g−1 for 4 hours. Moreover, this CCZ−G−T photocatalyst exhibits relatively high photocatalytic activity at (530−810) μmol·g−1 when using a scavenger, 1,190 μmol·g−1 when using a magnetic field of 0.14 T, and 1,230 μmol·g−1 when using ultrasonic waves. The CCZ−G−T composite exhibited 630 μmol·g−1 under a magnetic field condition of 0.14 T for 1 hour, which was significantly higher than the hydrogen production rate of 510 μmol·g−1 under ultrasonic conditions. The current study provides new insights into the magnetic field effect on the hydrogen evolution reaction (HER) of graphene-based photocatalysts.
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Sustainable Practices and Environmental Impact Assessment in a Lifelong Learning Center
(2024-01-01)
Koiwanit, Jarotwan
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Areerob, Yonrapach
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Saepoo, Sakkarin
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Filimonau, Viachaslau
Climate change is a major environmental challenge that should be mitigated by all parties concerned. One such party is the KMITL Lifelong Learning Canter (KLLC) which has committed to reducing its environmental externalities, including the impact of its operations on climate change. The idea of a “green KLLC” seeks to reduce adverse effects on the environment and improve indoor environmental quality through the use of natural building materials and biodegradable products, resource conservation (water, energy, paper), responsible waste disposal, and eco-friendly practices (recycling). To reduce these environmental externalities, the environmental performance of the KLLC canter should first be examined to establish measures for improvement. However, accurate evaluations of the environmental impact of Lifelong Learning Centers (LLCs) are uncommon because of the lack of data and the immaturity of appraisal methodologies. With a case study of KLLC, the newest LLC in Thailand, this paper appraises the environmental effects, thus setting benchmarks for subsequent studies. The appraisal demonstrates that the KLLC community can significantly reduce the environmental consequences by using e-certificates, motion sensor light installation, banana leaf packaging, solar cell installation, and carpooling systems. Although e-certificates and banana leaf packaging are the most cost-effective methods of implementation, the adoption of carpooling systems and electric vehicles demonstrates the highest potential for Greenhouse Gas (GHG) emissions reduction. The paper showcases how KLLC can reduce its GHG emissions and wastes, thus turning into a more environmentally sustainable business.
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Comparative catalytic approach of Ag doped ZnO with various nanocarbon materials toward CO2reduction with magnetic field and carbon form dependence
(2022-12-01)
Otgonbayar, Zambaga
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Areerob, Yonrapach
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Oh, Won Chun
Graphene oxide (GO) is a compromising catalyst material with a two-dimensional layer of carbon atoms having sp2 hybridization bonded in a hexagonal lattice structure. The gCN is a member of 2D-structured metal-free carbon materials. In this study, GO, gCN, fluorine, and nitrogen treated GO and ZnO-Ag (Ag doped ZnO) loaded carbon nanocomposites were studied. Fluorine and nitrogen treated GO is an up-rising carbon member. It has high stability. Its layer structure possess unique properties due to its C-F (covalent and semi -ionic) and C-N bonds. The computer simulations of all molecules were conducted using the Hartree-Fock function with a 6-311 G∗ mode on Spartan'14 software. A number of properties like molecule structure, electrostatic potential, local ionization potential, density, HOMO, and LUMO level of the molecules were obtained from computer simulations. Electrochemical CO<inf>2</inf> reduction to CH3OH on catalysts was investigated in different electrolysis conditions, such as different electrolytes with UV-light and 0.07 T magnetic core treatment. Results showed that the introduction of ZnO-Ag on carbon nanocomposites improved properties of carbon nanocomposites, leading to a high conversion of CO<inf>2</inf> to CH3OH. Methanol production rate was improved by five-times after UV-light (λ = 254 nm) and 0.07 T magnetic core treatment. Faradaic efficiencies of carbon nanocomposites for methanol production through electrochemical reduction of CO<inf>2</inf> in bicarbonate buffer and electrolytes were found to be 67.48% and 58.93% (compared to Ag/AgCl) at - 2.7 V, respectively. Charge carrier properties and morphology profile of these nanocomposites were also analyzed.
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The Physical and Sound Absorption Property of Lightweight Rigid Polyurethane Composite Reinforced Bamboo Fiber for Roof Applications
(2023-07-01)
Roseli, Adyla Illyana
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Hassan, Nik Normunira Mat
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Leman, Abdul Mutalib
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Latif, Najibah Abdul
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Aminanda, Yulfian
Rigid polyurethane (RPU) foams as roof insulation have become increasingly popular in Southeast Asian countries and have been extensively used for absorbing sound and reducing noise because of their good sound damping, viscoelasticity, and low density. In this study, the RPU foam composite reinforced bamboo fiber was investigated by physical characterization by SEM, TGA, and FTIR, and the sound absorption was measured by the Impedance Tube Test. The morphology result of the RPU foam composite indicates the size of the diameter pore influenced the sound absorption by adding bamboo fiber as a filler. The thermal degradation of the presence of lignin in the bamboo fiber at the temperature range of 400 °C to 500 °C and the total weight loss is 76 % at 429 °C temperature. FTIR spectrum shows that the peak at 2890 to 2935 cm-1 are indicated –CH stretching vibrations and characteristics for bamboo fiber can be used in polymer composites. The sound absorption of RPU 25 foam composite reinforced bamboo fiber was found 0.74 absorbance at a frequency of 1250 Hz. RPU foam reinforced bamboo fiber as a filler has the highest transmission loss RPU 35 is 21 dB at a frequency range of 1600 Hz. The findings indicate by increasing the content of bamboo fiber as filler, the diameter of the open pore of RPU 25 and RPU 35 foam composite had the potential for sound absorption to absorb at low frequency to achieve greater sound absorption for roof insulation.

Areerob, Yonrapach

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