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Enhancing electrochemical properties of an activated bamboo carbon-based supercapacitor with reduced graphene oxide nanocomposites through pulverizing and mixing in a 3-D high-speed ball mill
(2025-04-01)
Srichaiprapha, Kitima
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Ruttanapun, Chesta
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Sriwong, Chaval
Bamboo-activated carbon (AC-BBC) achieved improved electrochemical properties by compositing it with reduced graphene oxide (rGO) at 1, 3, 5, and 7% weight (wt%). The AC-BBC samples were prepared by annealing bamboo carbon (BBC) powder and a KOH mixture through flowing argon at 900 °C. It was pulverized and mixed using high-speed three-dimensional (3-D) ball milling. rGOx%/3D-AC-BBC (x = 1, 3, 5, and 7 wt%) samples, which are referred to as AC-BBC composites with x% rGO ground by 3-D ball milling, were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopy techniques. Analysis using scanning electron microscopy (SEM) and specific surface area (SSA) revealed that the rGO5%/3D-AC-BBC sample exhibited the highest specific surface area (SSA), 2239.80 m²/g, with an average pore size of 2.22 nm. Half-cell electrodes had the greatest specific capacities, 301.80 F/g at 0.5 A/g. The symmetric supercapacitor coil cell device showed a capacitance of 85.93 F/g, an energy density of 11.93 Wh/kg, and a power density of 49.56 W/kg. The efficiency retention was reduced to 96.76% after 10,000 cycles. This manuscript presents a high-performance rGO5%/3D-AC-BBC material that can be used for active electrodes to enhance electrochemical properties, making them suitable for electric double-layer capacitor (EDLC) applications.
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Synthesis and electrochemical properties of activated lignite carbons-reduced graphene oxide nanocomposites symmetric supercapacitors
(2024-08-15)
Tuichai, Wattana
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Karaphun, Attaphol
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Phrompet, Chaiwat
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Chanlek, Narong
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Swatsitang, Ekaphan
Ultra-fast chargeable or rechargeable symmetric carbon-based supercapacitors (SCSs) with high capacity, inexpensive, and non-flammability have attracted much attention for electronics and energy storage devices. However, improving both high redox reaction and ion transport/diffusion processes by enhancing high energy storage performance and rapid ion/electron transport SCSs electrode materials remains challenging. Herein, we presented a successful preparation of activated lignite carbons-reduced graphene oxide (ALC-rGO) nanocomposite (NCp) with the ALC:rGO ratio of 80:20 wt% by a one-pot hydrothermal for high electrochemical performance. Importantly, the matrix of ALC-rGO NCp was primary amorphous carbon with hexagonal graphitic layers and pore structures of plentiful micropores and mesopores. Remarkably, the ALC-rGO NCp electrode exhibited a maximum specific capacitance (C<inf>sc</inf>) of 152.12 F/g at 0.5 A/g. Interestingly, the SCSs-ACL-rGO device could illustrate a good performance at a potential voltage of 1.8 V with C<inf>sc</inf> of 50.90 F/g at 1 A/g and capacity retention of 96.0 % at 5 A/g after 2,000 cycles GCD test.
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Characterization and electrochemical properties of CuO–Cu2O@rGO nanocomposite synthesized by a seed-mediated growth process
(2022-04-01)
Wongjom, Poramed
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Tuichai, Wattana
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Karaphun, Attaphol
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Phrompet, Chaiwat
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Daengsakul, Sujittra
A CuO–Cu<inf>2</inf>O@rGO nanocomposite (CuO–Cu<inf>2</inf>O@rGO NCP) has been successfully prepared through a seed-mediated growth process. X-ray diffraction (XRD) analysis results indicated a monoclinic phase of CuO–Cu<inf>2</inf>O@rGO NCP with space group C2/c. Transmission electron microscopy (TEM) revealed agglomeration of the CuO and Cu<inf>2</inf>O nanoparticles in the rGO sheet matrix. The interaction of CuO–Cu<inf>2</inf>O@rGO NPC resulted from the aggregation and overlapping of CuO and Cu<inf>2</inf>O nanoparticles owing to the influence of a seed-mediated growth process. The electrochemical properties of the CuO–Cu<inf>2</inf>O@rGO NPC electrode indicate the storage of energy at the surface through a pseudo-capacitive mechanism. The specific capacitance at a current density of 0.5 A g−1 and the average percentage capacity retention after 1000 cycles of a CuO–Cu<inf>2</inf>O@rGO electrode at a current density of 10 A g−1 were evaluated as 125.54 F g−1 and 89.87 ± 3.30%, respectively. In the CuO–Cu<inf>2</inf>O@rGO electrode, the incorporated rGO affects the electrical conductivity and the synergistic interactions in charge–discharge processes. Interestingly, these results showed that the material was synthesized through a seed-mediated growth process and reveal the key factors that determine the combination and volume expansion of the reversible redox transition between Cu+ and Cu2+ during charge–discharge processes.
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Improved dielectric properties of PVDF polymer composites filled with Ag nanomaterial deposited reduced graphene oxide (rGO) hybrid particles
(2022-01-01)
Tuichai, Wattana
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Karaphun, Attaphol
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Ruttanapun, Chesta
We report a method to improve the dielectric constant (ε′) of polyvinylidene fluoride (PVDF) composites by using a low content of Ag nanomaterials deposited reduced Graphene Oxide (rGO) Hybrid Particles (Ag-rGO HPs). The Ag-rGO HPs are prepared by a reaction between silver nitrate and ethylene glycol in a seed-mediated growing process. The dispersion of Ag nanomaterials was completely homogeneous on the surface of rGO nanosheets with particle sizes of 5.765 ± 0.189 nm. The Ag-rGO HPs/PVDF composites were produced by a liquid–phase assisted dispersion and hot-pressing methods. The high ε′ at 103 Hz for Ag-rGO/PVDF composites with f<inf>Ag-rGO</inf> 7.8, and 11.9 vol% was 153 and 683, respectively. The best-fitting curve was completely achieved in percolation theory by adjusting f<inf>c</inf> = 14 vol%. The high ε′ (683 at 1 kHz) of Ag-rGO/PVDF could be explained by Maxwell Wagnare Sillars interfacial polarization and micro-capacitor due to the formation of a sandwich between Ag-rGO and PVDF.
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Influence of free electron charge and free extra framework anions in calcium aluminate@ rGO (CA@ rGO) cement composites with enhanced dielectric and electrochemical properties
(2021-10-01)
Ruttanapun, Chesta
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Phrompet, Chaiwat
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Tuichai, Wattana
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Karaphun, Attaphol
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Daengsakul, Sujittra
Nowadays, the metal oxide-based composites loaded with reduced graphene oxide (rGO) nano sheets are believed to enhance both the electrochemical and dielectric properties. In this study, therefore, the effect of rGO loading contents on the calcium aluminate (CA), namely CA@ rGO, cement composites with high dielectric and electrochemical properties is presented. CA@ rGO composites were successfully synthesized via a simple direct mixing of CA cement with various contents of graphene oxide (GO) precursors followed by a conventional thermal reduction method. Based on XRD and Raman spectroscopy results, all prepared CA@ rGO composites clearly confirmed both the structure of the pristine CA cement as well as the complete conversion of GO precursors to rGO after thermal reduction, and the existence of rGO nano sheets on the surface of CA@ rGO composites. The impedance value results revealed that the enhancement of a high dielectric constant was achieved in the CA@ rGO composites due to both typical interface polarization and the micro-capacitor of CA cement and rGO nano sheets. Meanwhile, the prepared CA@ rGO-4 composite electrode exhibited the highest of electrochemical double-layer capacitive behavior with the specific capacitance (C<inf>sc</inf>) value of 79.33 F g−1 at 0.2 A g−1. The enhanced super-capacitive performance of CA@ rGO composite can be improved by the synergistic effect of free electron transfer and electron diffusion between the CA cement interface and rGO nano sheets.
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Facile and green synthesis of Melamine-Formaldehyde@rGO foam with enhanced superhydrophobicity for oil removal application
(2021-01-01)
Jirasuttisarn, Natcha
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Sriwong, Chaval
This research presented a more effective method to synthesize superhydrophobic melamine-formaldehyde (MF) foam coated with reduced graphene oxide (MF@rGO) by a conventional heating process. This is a facile and green method based on the use of graphene oxide, GO, as a precursor, and vitamin C as a reductant. The effect of recoating GO onto MF@rGO to form MF@rGO-recoat foam on superhydrophobicity was also investigated. Then, pristine GO, rGO, MF and as-synthesized MF@rGO foams were analyzed and their structures confirmed by several techniques including FTIR, Raman, SEM, TEM, and water contact angle (WCA). The results indicated that the WCA values of MF@rGO and MF@rGO-recoat foams were increased from 144.1° to 156.9°, respectively. Furthermore, the adsorption capacity (Qe), oil removal performance, and recyclability of MF@rGO-recoat foam were investigated. The adsorption capacity of MF@rGO-recoat foam was higher than 103.8 g.g-1 for all the oils tested (palm oil, gasoline, diesel and lubricant oil), and the highest value was 115.9 g.g-1 for lubricant oil. Besides, MF@rGO-recoat foam can be easily recycled up to 10 times for removal of all oils tested. Thus, this work provides a new alternative eco-friendly way to synthesize MF foam coated with rGO sheets and the synthesized MF@rGO foam can be applied and reused for the removal of oil spillages from water or wastewater.
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Electrochemical properties of tricalcium aluminate hexahydrate − reduced graphene oxide nanocomposites for supercapacitor device
(2020-08-01)
Phrompet, Chaiwat
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Maneesai, Keerati
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Tuichai, Wattana
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Karaphun, Attaphol
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Sriwong, Chaval
In this study, the influence of reduced graphene oxide (rGO)−Tricalcium Aluminate Hexahydrate (C3AH6) cement nanocomposites on electrochemical properties was investigated. The rGO-C3AH6 nanocomposite samples with various of rGO laoding, such as, C3AH6_rGO-1, 3, 5, 7, 10 and 20 wt.% were easily synthesized by a rapid cement hydration method. The maximum specific surface area and average pore size diameters were 74.20 m2/g and 11.72 nm for C3AH6_rGO-20%. The charge tranfering in C3AH6_rGO nanocomposites was described using band alignments model occurring between C3AH6 and rGO. Interestingly, the increasing of both dielectric property and stability in frequency of C3AH6_rGO composite samples can be explained by the high density of free electron charges on the rGO surface. Moreover, the electrochemical properties of C3AH6_rGO electrodes had excellent capacitive properties displaying the storage charge mechanism of a hybridsupercapacitor behavior. The large rGO content of the C3AH6_rGO nanocomposite capacitor with electrolyte interfaces showed excellent electrochemical performance. The highest value of 80.479 F g −1 was obtained from C3AH6_rGO-20% at a current density of 0.2 A g −1 with cycling stability of 96.51% after 1000 cycles.
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Mechanical, dielectric, thermal and antibacterial properties of reduced graphene oxide (rGO)-nanosized C3AH6 cement nanocomposites for smart cement-based materials
(2019-10-15)
Phrompet, Chaiwat
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Sriwong, Chaval
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Ruttanapun, Chesta
This work aimed to fabricate nanocomposites of reduced graphene oxide (rGO)-nanosized C3AH6 cement via a rapid cement hydration for enhancing its micro-hardness, dielectric constant, thermal conductivity, electrochemical and antibacterial properties.rGO-nanosized C3AH6 nanocomposites (∼10–20 nm in diameter) with 1, 2, 3, and 4% weight of rGO, were successfully synthesized from a Ca12Al14O33 and rGO colloid that was rapidly heated with water to a temperature of 100 °C. Nanocomposites of x%rGO-C3AH6 (x = 1, 2, 3, and 4) were characterized using XRD, UV–vis spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and TGA techniques. The chemical composition was confirmed using SEM and EDX characterization. The results revealed a nanocomposited rGO-C3AH6 material with nanosheet and nanoflaked rGO, as well as nanosized C3AH6 particles. The results presented rGO-C3AH6 with high performance multifunctional properties that included enhanced mechanical, dielectric, and thermal properties. The vickers micro-hardness and dielectric constant were enhanced by the effect of rGO-C3AH6 nanocomposites. The thermal conductivity of rGO-C3AH6 was higher than that of C3AH6. The electrical conductivity and electrochemical properties were effectively increased with greater levels of rGO in the material. Its antibacterial activity was confirmed by the formation of clearing zones on a Petri plate seeded with Escherichia coli (E. coli). The diameter of these zones increased with the rGO content. These results confirmed that nanocomposited rGO-C3AH6 was effective in enhancing mechanical, dielectric and thermal properties while serving as a high performance multifunctional cement-based material.
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Preparation and photocatalytic activities of tio2-rgo nanocomposite catalysts for mb dye degradation over sunlight irradiation
(2018-01-01)
Sriwong, Chaval
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Choojun, Kittisak
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Tejangkura, Worapol
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Prasanseang, Warot
This research aims to investigate photocatalytic activities of titanium dioxide (TiO<inf>2</inf>) incorporated with reduced graphene oxide (rGO) nanocomposite catalysts. These TiO<inf>2</inf>-rGO photocatalysts were easily prepared through a direct-mixing of TiO<inf>2</inf> powder suspended in acidic solution under the different amounts of rGO loading (0.25, 0.50, 0.75 and 1.00 wt%). Then, the obtained TiO<inf>2</inf>-rGO samples were characterized by a several techniques. The results demonstrated that the crystalline phases of all samples are corresponding to pristine TiO<inf>2</inf>, whereas the characteristic peaks of rGO in the TiO<inf>2</inf>-rGO nanocomposites could be observed and also confirmed by Raman spectroscopy. TEM results showed that the TiO<inf>2</inf> nanoparticles were well-combined with rGO nanosheets. Moreover, the photocatalytic activities of all TiO<inf>2</inf>-rGO photocatalyst samples were evaluated by photodegrading of methylene blue (MB) dye solution under natural sunlight irradiation. The results revealed that all TiO<inf>2</inf>-rGO nanocatalysts exhibited much higher activity than those of the bare TiO<inf>2</inf>. The improved photocatalytic activity can be attributed to the presence of rGO nanosheets, leading to the decrease of electron (e-)-hole (h+) recombination of TiO<inf>2</inf> catalyst, increasing charge transfer rate of electrons and surface-adsorbed amount of MB molecules which enhances the photocatalytic activity.
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Preparation, characterization and photocatalytic properties of rubber-TiO2-rGO composite sheets for dye decomposition in wastewater
(2017-01-01)
Tejangkura, Worapol
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Sriwong, Chaval
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Choojun, Kittisak
In this work, rubber-TiO<inf>2</inf>-rGO (RT-rGO) composite sheets were successfully prepared by a simple latex mixing-casting method using TiO<inf>2</inf> and natural rubber latex with different amounts of rGO loading. The prepared RT-rGO sheet samples were characterized by XRD, FT-IR, Raman, SEM and EDS techniques. The photocatalytic properties of the prepared RT-rGO sheets as catalyst were evaluated using methylene blue (MB) dye solution under UV light irradiation. The result indicated that all the composite sheets loaded with rGO had better photocatalytic activities than the sheet without rGO loading. RT-rGO6.2% sheet showed the highest removal efficiency of 93.3% which has the rate constant (kapp) as 98.2 times higher than the unloaded sheet. Furthermore, the efficiency of the RT-rGO sheet upon the repeated usage was also studied. The result indicated that the sheet could be easily used, recovered and reused many times with no need for the cleaning in between successive uses. Thus, the RT-rGO sheet appears to be an attractive-material for the wastewater treatment or the water purification industry.

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