Fabrication of a solid-state symmetrical supercapacitor based on polyaniline grafted multiwalled carbon nanotube deposit onto Created Vertically Oriented Graphene Nanosheets on graphite sheet
“…The surface area, volume, and pore diameter of the leached graphite were greatly enhanced after its treatment in sulfuric acid, as shown in Fig. 3 e,f and (Table 1 ) 48 . Figure 3 SEM images of electrocatalysts ( a ) non- leached graphite, ( b ) The leached graphite, ( c ) The leached Fe 1 –Pd 1 /G ( d ) TEM image of leached Fe 1 –Pd 1 /G electrocatalyst, ( e ) BET N 2 adsorption–desorption isotherm ( f ) BJH pore size distribution.…”
Section: Resultsmentioning
confidence: 81%
“…Due to the difference of 11 degrees in the average contact angles between the two electrodes, 64 degrees for the non-leached graphite electrode and 53 degrees for the leached graphite electrode, it is discovered that the modified leached graphite electrode has hydrophilic properties and surface area. Decreasing the contact angle of electrode can significantly improve the electrocatalytic activity of the electrode due to increase the wettability for electrooxidation of methanol molecules dissolved in water 48 . Figure 4 Drop test images related to electrocatalysts ( a ) non- leached graphite and ( b ) The leached graphite.…”
This paper introduces a unique and simple method for fabricating of inexpensive electrocatalysts for use in direct methanol fuel cells. The leached Fe1–Pd1 NFs/graphite (leached Fe1–Pd1/graphite) disk electrode was successfully obtained via uniform dispersion of Zn powder into the matrix of commercial graphite powder (98%), pressing under optimized pressure followed by the treatment in H2SO4 solution containing Fe+2 and Pd+2 cations, leading to the partial leaching out of Zn from graphite matrix, as well as partial electroless substitution of Fe–Pd nanoflakes with Zn metal. Based on the morphology studies, binary Fe–Pd nanoflakes with a large surface area uniformly dispersed on the leached graphite disk. The leached Fe–Pd/G disk showed the exceptional electrocatalytic activity toward methanol and formic acid oxidation without electrocatalyst poisoning being observed, in contrast to the leached Pd/graphite and leached Fe/graphite disks. This is due to the high surface area, and synergistic effect of Pd and Fe. The findings of this work may be used for the mass manufacture of graphite-based disks for commercial fuel cell applications using available graphite powders. The linear range of washed Fe1–Pd1/G electrocatalyst for measuring methanol was about 0.1–1.3 M, and its detection limit was calculated at about 0.03 M. Furthermore, the linear range of the nanocatalyst for measuring formic acid was about 0.02–0.1 M, and its detection limit was calculated at about 0.006 M.
“…The surface area, volume, and pore diameter of the leached graphite were greatly enhanced after its treatment in sulfuric acid, as shown in Fig. 3 e,f and (Table 1 ) 48 . Figure 3 SEM images of electrocatalysts ( a ) non- leached graphite, ( b ) The leached graphite, ( c ) The leached Fe 1 –Pd 1 /G ( d ) TEM image of leached Fe 1 –Pd 1 /G electrocatalyst, ( e ) BET N 2 adsorption–desorption isotherm ( f ) BJH pore size distribution.…”
Section: Resultsmentioning
confidence: 81%
“…Due to the difference of 11 degrees in the average contact angles between the two electrodes, 64 degrees for the non-leached graphite electrode and 53 degrees for the leached graphite electrode, it is discovered that the modified leached graphite electrode has hydrophilic properties and surface area. Decreasing the contact angle of electrode can significantly improve the electrocatalytic activity of the electrode due to increase the wettability for electrooxidation of methanol molecules dissolved in water 48 . Figure 4 Drop test images related to electrocatalysts ( a ) non- leached graphite and ( b ) The leached graphite.…”
This paper introduces a unique and simple method for fabricating of inexpensive electrocatalysts for use in direct methanol fuel cells. The leached Fe1–Pd1 NFs/graphite (leached Fe1–Pd1/graphite) disk electrode was successfully obtained via uniform dispersion of Zn powder into the matrix of commercial graphite powder (98%), pressing under optimized pressure followed by the treatment in H2SO4 solution containing Fe+2 and Pd+2 cations, leading to the partial leaching out of Zn from graphite matrix, as well as partial electroless substitution of Fe–Pd nanoflakes with Zn metal. Based on the morphology studies, binary Fe–Pd nanoflakes with a large surface area uniformly dispersed on the leached graphite disk. The leached Fe–Pd/G disk showed the exceptional electrocatalytic activity toward methanol and formic acid oxidation without electrocatalyst poisoning being observed, in contrast to the leached Pd/graphite and leached Fe/graphite disks. This is due to the high surface area, and synergistic effect of Pd and Fe. The findings of this work may be used for the mass manufacture of graphite-based disks for commercial fuel cell applications using available graphite powders. The linear range of washed Fe1–Pd1/G electrocatalyst for measuring methanol was about 0.1–1.3 M, and its detection limit was calculated at about 0.03 M. Furthermore, the linear range of the nanocatalyst for measuring formic acid was about 0.02–0.1 M, and its detection limit was calculated at about 0.006 M.
“…The specific capacitance from the GCD curves in the three-electrode system was calculated using , where I , Δ t , m, and Δ v have their usual meanings. 37 The calculated specific capacitance values were 354.50 and 436.81 F/g at 1 A/g. All remaining specific capacitance values of other current densities are listed in Table 2 .…”
Section: Resultsmentioning
confidence: 90%
“…As illustrated in Figure c,d, charging and discharging curves of the two electrodes formed a perfect triangular shape and were almost symmetrical to their corresponding current density curves. The specific capacitance from the GCD curves in the three-electrode system was calculated using Cnormals=I×normalΔtm×(Vf−Vi), where I , Δ t , m, and Δ v have their usual meanings . The calculated specific capacitance values were 354.50 and 436.81 F/g at 1 A/g.…”
In the modern civilized world, energy scarcity and associated
environmental pollution are the center of focus in the search for
reliable energy storage and harvesting devices. The need to develop
cheaper and more competent binder-free electrodes for high-performance
supercapacitors has attracted considerable research attention. In
this study, two different procedures are followed to enhance the growth
of carbon nanotubes (CNT-E and CNT-NF) directly coated on a Ni-foam
substrate by a well-functioning chemical vapor deposition (CVD) method.
Thus, directly grown optimized CNT electrodes are used as electrodes
for electrochemical devices. Furthermore, solid-state symmetric supercapacitors
are fabricated using CNT-NF//CNT-NF, and fruitful results are obtained
with maximum specific capacitance (250.51 F/g), energy density (68.19
Wh/kg), and power density (2799.77 W/kg) at 1 A/g current density.
The device exhibited good cyclic stability, with 92.42% capacitive
retention and 99.68% Coulombic efficiency at 10 000 cycles,
indicating the suitability of the electrodes for practical applications.
This study emphasizes the importance of studying the direct growth
of binder-free CNT electrodes to understand the actual behavior of
electrodes and the proper storage mechanism.
“…Fabrication of a symmetrical supercapacitor was based on the CNT/PANI/graphene/graphite electrode with a high surface area, described in Ref. [105]. The paper demonstrated the SC of 880 F/g at a current density of 1.5 A/g, an energy density of 68.4 mWh/g, a power density of 895.4 mW/g, and 80.6% CR after 10,000 cycles.…”
Carbon nanotubes (CNTs), due to mechanical, electrical, and surface area properties and their ability to adapt to different nanocomposite structures, are very substantial in supercapacitor electrodes. In this review, we have summarized high-performance, flexible, and symmetry CNT supercapacitors based on the CNTs/graphene, CNTs/metal, and CNTs/polymer electrodes. To present recent developments in CNT supercapacitors, we discuss the performance of supercapacitors based on electrical properties such as specific capacitance (SC), power and energy densities, and capacitance retention (CR). The comparison of supercapacitor nanocomposite electrodes and their results are reported for future researchers.
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