Areerob, Yonrapach
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Item type:Publication, Novel gamma-irradiated chitosan-doped reduced graphene-CuInS2 composites as counter electrodes for dye-sensitized solar cells(2022-05-20); ;Hamontree, Chaowalit ;Sricharoen, Phitchan ;Limchoowong, NuntichaLaksee, SakchaiTo 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. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, 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 ;Keawprom, Chayanee; ;Limchoowong, NuntichaSricharoen, PhitchanThe 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 Fe<sup>2+</sup> over Fe<sup>3+</sup> 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 Fe<sup>3+</sup> presence in the target analyte were all optimized for Fe<sup>2+</sup> detection. A highly sensitive detection of Fe<sup>2+</sup> was obtained using a linear curve with y = 141.34x + 5.5855, R<sup>2</sup> = 0.9961, LOD = 0.11 mg L<sup>−1</sup>, and LOQ = 0.35 mg L<sup>−1</sup>. 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 Fe<sup>2+</sup> 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%. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, 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; ;Yang, Sunhye ;Kim, Ick JunOh, Won ChunIt 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. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, 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); ;Sagadevan, SureshOh, Won ChunCOVID-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. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, 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); ;Rafat, Md Nazmodduha ;Ullah, KefayatOh, Won ChunA 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. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Magnetic and ultrasonic integrated photocatalytic hydrogen evolution effects with Nanosize CoOCu2OZnO and TiO2 decorated on reduced graphene oxide(2023-12-01); ;Meng, Zeda ;Ullah, Kefayat ;Wijaya, KarnaOtgonbayar, ZambagaIn 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<sup>−1</sup> for 4 hours. Moreover, this CCZ−G−T photocatalyst exhibits relatively high photocatalytic activity at (530−810) μmol·g<sup>−1</sup> when using a scavenger, 1,190 μmol·g<sup>−1</sup> when using a magnetic field of 0.14 T, and 1,230 μmol·g<sup>−1</sup> when using ultrasonic waves. The CCZ−G−T composite exhibited 630 μmol·g<sup>−1</sup> 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<sup>−1</sup> under ultrasonic conditions. The current study provides new insights into the magnetic field effect on the hydrogen evolution reaction (HER) of graphene-based photocatalysts. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, 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; Oh, Won ChunGraphene 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. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Photocatalytic decolorization of ZnO/Fe for the removal of methylene blue by new microwave methodology(2022-04-01); ;Oh, Won ChunPattarith, KongsakThe photocatalysis of ZnO/Fe was performed by the simple microwave method for the removal of methylene blue. All samples were found to possess a single-phase monoclinic scheelite structure. On loading 5.0 mol% of Fe to the samples, the photocatalytic activities were enhanced, suggesting the potential application of the material as a superior visible light-driven photocatalyst relative to pure ZnO for the decolorization of methylene blue dye. The enhanced decolorization activity of the photocatalyst demonstrated the ability of Fe to reduce the band gap energy of ZnO and improve the electron transfer in the ZnO/Fe adsorbent. Moreover, the ultraviolet–visible absorption experiments exhibited an excellent decolorization rate (30 min) along with a decolorization efficiency of 93% upon the UV irradiation of ZnO/Fe in the pH range. The possible reaction mechanism and decolorization pathway of the photocatalyst were discussed in detail, and the stability of the catalyst was confirmed by the reusability test. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Synthesis of novel MoWO4 with ZnO nanoflowers on multi-walled carbon nanotubes for counter electrode application in dye-sensitized solar cells(2022-12-01); ;Hamontree, Chaowalit ;Sricharoen, Phitchan ;Limchoowong, NuntichaNijpanich, SupinyaNovel MoWO<inf>4</inf> with ZnO nanoflowers was synthesized on multi-walled carbon nanotubes (MW-Z@MWCNTs) through a simple hydrothermal method, and this unique structure was applied as a counter electrode (CE) for dye-sensitized solar cells (DSSC) for the first time. The synergetic effect of ZnO nanoflowers and MoWO<inf>4</inf> on MWCNTs was systematically investigated by different techniques. The amount of MWCNTs was optimized to achieve the best DSSC performance. It was found that the 1.5% MW-Z@MWCNTs composite structure had the highest power conversion efficiency of 9.96%, which is greater than that of traditional Pt CE. Therefore, MW-Z@MWCNTs-based CE can be used to replace traditional Pt-based electrodes in the future. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A novel of WS2–MoCuO3 supported with graphene quantum dot as counter electrode for dye-sensitized solar cells application(2023-12-01); ;Oh, Won Chun ;Hamontree, Chaowalit ;Nachaithong, TheeranuchNijpanich, SupinyaA novel tungsten disulfide-molybdenum copper oxide composite supported with graphene quantum dots (WM@GQDs) has been synthesized as a counter electrode (CE) for dye-sensitized solar cells (DSSCs) using a simple and low-cost ultrasonication method. The unique structure of WM@GQDs exhibits excellent power conversion efficiency due to its high catalytic activity and charge transport properties. In addition, the graphene quantum dots (GQDs) provide more active sites in the zero-dimensional materials for an I/I<inf>3</inf><sup>−</sup> redox reaction which can improve the electrical and optical properties of the composite. The results indicate that the amount of GQDs in the composite affect the effectiveness of solar devices. When 0.9%wt of GQDs was used, the WM@GQDs composite achieved an efficiency of 10.38%, which is higher than that of the expensive platinum CE under the same conditions. The mechanism behind the improved power conversion efficiency (PCE) of the composite sample is also discussed in detail. Therefore, WM@GQDs can be an efficient material to replace platinum in DSSCs as a CE.
