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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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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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Dielectric and electrochemical properties of hybrid Pt nanoparticles deposited on reduced graphene oxide nanoparticles /poly (vinylidene fluoride) nanocomposites
(2021-06-01)
Karaphun, Attaphol
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Tuichai, Wattana
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Chanlek, Narong
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Sriwong, Chaval
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Ruttanapun, Chesta
Nano-sized platinum (Pt) materials deposited on reduced Graphene Oxide (rGO) nanosheets (hybrid Pt-rGO nanoparticle) were prepared by the seed-mediated growing process using 20 wt% of Pt nanomaterials in rGO suspension. Dielectric properties of hybrid Pt-rGO nanoparticles/poly (vinylidene fluoride) nanocomposites (Pt-rGO/PVDF nanocomposites) were synthesized by a liquid–phase assisted dispersion and hot–pressing methods with different volume fractions (f) of hybrid Pt-rGO nanoparticle loading PVDF nanocomposites. The observed particle size of Pt nanomaterials deposits on rGO nanosheets was 5 nm. The dielectric constant (ε′) of Pt-rGO/PVDF nanocomposites was increased with increasing hybrid Pt-rGO nanoparticle. The volume fraction f<inf>Pt-rGO</inf> ≈0.0786 exhibited excellent ε′ ≈ 86 with very low loss tangent (tanδ) ≈ 0.021 at 1 kHz. High dielectric properties of Pt-rGO/PVDF composite should be ascribed to combination of the micro-capacitor and Maxwell–Wagner–Sillars (MWS) effects. Electrochemical properties of speciﬁc capacitances (C<inf>sc</inf>) and capacity retention of hybrid Pt-rGO nanoparticle electrode were investigated by the cyclic voltammetry and the galvanostatic charge-discharge. Interestingly, the hybrid Pt-rGO nanoparticle electrode displayed maximum C<inf>sc</inf> value of 169.8 F g−1 at the current densities of 0.25 A g−1. This was due to the occurrence of various oxygen functional groups in the rGO- and Pt+ ions as contributing to form of pseudo-capacitance in hybrid Pt-rGO nanoparticle.
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The influence of annealing on a large specific surface area and enhancing electrochemical properties of reduced graphene oxide to improve the performance of the active electrode of supercapacitor devices
(2021-02-01)
Karaphun, Attaphol
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Phrompet, Chaiwat
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Tuichai, Wattana
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Chanlek, Narong
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Sriwong, Chaval
Influence of annealing process on microstructure, large specific surface area and enhancing electrochemical properties to synthesize reduced graphene oxide (rGO) for the supercapacitor electrode was investigated. Thermal annealing process of rGO (rGO_An) was improved crystallinity and electrical conductivity. BET analysis of rGO_An sample exhibited the occurrence of large mesoporous and macrospores with a huge specific surface area of 672.1 m2/g and an average pore size of 46.2 nm, resulting the rGO_An sample activates more electrodes than rGO sample. Specific capacitance (C<inf>s</inf>) was affected by improving conductivity through annealing process with an excellent cycling stability after 750 cycles for GCD tests of 97.32%, which exhibited the highest value and an average energy density of 412.096 F g−1 and 74.5 Wh kg−1, respectively at 1 A g−1. Thus, annealing process can occur with large mesoporous and macrospores pore improving the electrical conductivity and stability to be applied as an electrode in supercapacitor.
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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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Effect of grain boundary interfaces on electrochemical and thermoelectric properties of a Bi2Te3/reduced graphene oxide composites
(2020-08-01)
Thongsamrit, Wannisa
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Phrompet, Chaiwat
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Maneesai, Keerati
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Karaphun, Attaphol
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Tuichai, Wattana
The electrochemical and enhanced thermoelectric properties of pristine Bi<inf>2</inf>Te<inf>3</inf> and Bi<inf>2</inf>Te<inf>3</inf>/reduced graphene oxide (Bi<inf>2</inf>Te<inf>3</inf> + rGO) composites at 1%, 3% and 5% levels of rGO were synthesized via a simple ultrasonic method. The X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV–vis spectrometry (UV–vis) and their electrochemical and thermoelectric properties were measured. The ultrasonic method succeeded in producing rGO nanosheets composited with Bi<inf>2</inf>Te<inf>3</inf> forming grain boundary interfaces of rGO with Bi<inf>2</inf>Te<inf>3</inf>. The resulting samples displayed a continuous network structure of rGO nanosheets in Bi<inf>2</inf>Te<inf>3</inf> + rGO composites for electrons in the conduction band of the Bi<inf>2</inf>Te<inf>3</inf> structure. Electrons were transferred to rGO nanosheets at the interface, contributing electron charge carriers in Bi<inf>2</inf>Te<inf>3</inf> + rGO composites. This indicates band alignment between Bi<inf>2</inf>Te<inf>3</inf> and rGO nanosheets. The Bi<inf>2</inf>Te<inf>3</inf> + rGO composites exhibited an increasing storage charge mechanism of electrical double layer capacitors with greater rGO contents. The Bi<inf>2</inf>Te<inf>3</inf> + rGO composites displayed negative a Seebeck coefficient for thermoelectric materials. The highest ZT value was 0.17 in the bulk 1% Bi<inf>2</inf>Te<inf>3</inf> + rGO composite. Improved electrochemical and thermoelectric properties of the Bi<inf>2</inf>Te<inf>3</inf> + rGO 1% composite resulted from the interaction of the grain boundary interfaces of rGO nanosheets with pristine Bi<inf>2</inf>Te<inf>3</inf> following the model of band alignment between Bi<inf>2</inf>Te<inf>3</inf> and rGO nanosheets.

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