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New hybrid high performance dye-sensitized solar cells using CoNi2Se4@SiO2 core-shell integrated with graphene quantum dots as counter electrodes
(2026-10-01)
Areerob, Yonrapach
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Nachaithong, Theeranuch
;
Phumuen, Phatcharin
;
Wannabut, Wassana
;
Nijpanich, Supinya
A novel CoNi₂Se₄@SiO₂ core–shell nanostructure decorated with graphene quantum dots (CNS@Si–GQDs) was synthesized via a simple hydrothermal method and investigated as a Pt-free counter electrode for dye-sensitized solar cells (DSSCs). The optimized CNS@Si–GQDs electrode with 7 ppm GQD loading exhibited excellent electrocatalytic activity toward the I₃−/I− redox reaction, delivering a photoelectric conversion efficiency (PCE) of 8.10%, slightly higher than that of the conventional Pt electrode (8.03%). The optimized device also achieved a high short-circuit current density (Jsc) of 18.67 mA cm−2, with a Voc of 0.75 V and a fill factor (FF) of 0.57. Electrochemical impedance spectroscopy revealed that the CNS@Si–GQDs (7 ppm) electrode possessed the lowest charge-transfer resistance (Rct = 241.62 Ω cm2), significantly lower than those of the 3 ppm and 5 ppm electrodes, indicating enhanced interfacial electron-transfer kinetics and catalytic activity. Tafel polarization analysis further confirmed improved exchange current density and faster triiodide reduction kinetics after GQD incorporation. The enhanced electrochemical performance was attributed to the synergistic interaction between the conductive GQD network and the CNS@SiO₂ core–shell structure, which increased the electroactive surface area, promoted electron mobility, and provided abundant catalytic active sites. Additionally, the SiO₂ interfacial layer helped suppress charge recombination and stabilize the hierarchical nanostructure. This study demonstrates a scalable, low-cost, and efficient Pt-free strategy for next-generation DSSCs and provides insights into the design of advanced electrocatalysts for sustainable solar energy conversion.
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A novel of WS2–MoCuO3 supported with graphene quantum dot as counter electrode for dye-sensitized solar cells application
(2023-12-01)
Areerob, Yonrapach
;
Oh, Won Chun
;
Hamontree, Chaowalit
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Nachaithong, Theeranuch
;
Nijpanich, Supinya
A 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>− 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.
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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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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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Mesoporous Cu-doped BaTiO3-G-SiO2-based easy-to-use electrochemical biosensor for sensing pathogenic S. aureus biofilm
(2023-01-01)
Areerob, Yonrapach
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Meng, Ze da
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Cho, Kwang Youn
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Jung, Chong Hun
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Cho, Ju Yong
Biofilms are primary causes of clinical bacterial infections. They are resistant to typical amounts of antibiotics, necessitating very high doses for elimination. Therefore, it is imperative to establish sensitive, rapid, and timely methods for the detection of Staphylococcus aureus (S. aureus) biofilm. The aim of this research was to develop an easy-to-use electrochemical sensor for sensing pathogenic S. aureus biofilms. We developed mesoporous Cu-doped BaTiO<inf>3</inf>-G-SiO<inf>2</inf> (CBTGS)-based electrodes to investigate their electrochemical detection ability for S. aureus biofilms. Results revealed that mesoporous CBTGS electrode in biosensing devices provided high sensitivity and stability for electrochemical detection of S. aureus biofilms. When the mesoporous morphology of CBTGS was compared to that of Cu-doped BaTiO<inf>3</inf>-G or Cu-doped BaTiO<inf>3</inf>, it showed a higher surface area with more active sites for attaching S. aureus biofilms, leading to its higher electron transfer resistance. As a result, it enabled rapid detection. A linear relationship between the increment in electron transfer resistance and the logarithmic value of S. aureus biofilm concentration was observed between 40 and 200 µL. The limit of detection was observed to be 5 µL. Finally, a good selectivity versus S. enterica (Salmonella enterica) and P. aeruginosa (Pseudomonas aeruginosa) was obtained for our developed mesoporous CBTGS, demonstrating its specificity towards only Staphylococcus aureus biofilms.
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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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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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Synthesis of novel MoWO4 with ZnO nanoflowers on multi-walled carbon nanotubes for counter electrode application in dye-sensitized solar cells
(2022-12-01)
Areerob, Yonrapach
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Hamontree, Chaowalit
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Sricharoen, Phitchan
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Limchoowong, Nunticha
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Nijpanich, Supinya
Novel 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.
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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
;
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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A flexible mesoporous Cu doped FeSn-G-SiO2 composite based biosensor for microalbumin detection
(2022-11-08)
Areerob, Yonrapach
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Chanthai, Saksit
;
Oh, Won Chun
A new mesoporous Cu-doped FeSn-G-SiO<inf>2</inf> (CFSGS) based biosensor was developed for the detection of microalbumin in urine samples. The mechanically flexible FeSn modified sensor was fabricated at room temperature. These demonstrations highlight the unexplored potential of FeSn for developing novel biosensing devices. It is extremely sensitive and selective. Surfactant-aided self-assembly was used to synthesise the mesoporous CFSGS. The large surface area due to the mesopore presence in the CFSG surface that has been composited inside the mesoporous SiO<inf>2</inf> boosted the electrochemical detection. The linear range and detection limit of microalbumin under optimum circumstances were 0.42 and 1 to 10 μL, respectively. This easily fabricated mesoporous CFSGS provided a fast response with high sensitivity, and good selectivity. The sensor's reusability and repeatability were also quite high, with just a 90 percent drop after 4 weeks of storage at ambient temperature. The biosensor also demonstrated high selectivity against typical potential interfering chemicals found in urine (ascorbic acid, urea, and sodium chloride). The good performance of the mesoporous CFSGS biosensor was validated by measuring microalbumin, and the findings indicated that this sensing device performed very well.

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