간행물
Carbon Letters KCI 등재 Carbon letters
- 발행기관 한국탄소학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1976-4251 (Print)2233-4998 (Online)
- 수록기간 2000 ~ 2023
- 주제분류 자연과학 > 자연과학일반 자연과학 분류의 다른 간행물
- 십진분류KDC 530DDC 620
권호리스트/논문검색
Vol.31 No.4 (2021년 8월) 25건
1.
2021.08
구독 인증기관 무료, 개인회원 유료
Research on Graphene and its importance in the field of energy conversion and storage devices such as fuel cells, batteries, supercapacitors and solar cells has gained momentum recently. It is studied to be the most suitable electrode material for enhanced performance of supercapacitors in terms of charge–discharge cycles, specific capacitance, high power and energy densities and so on, specifically due to its high conductivity and large theoretical surface area. Unfortunately, it posits lot of challenges due to its irreversible stacking between the individual sheets resulting in the decrease in the Specific Surface Area (SSA) compared to the theoretically reported values. Numerous studies have been carried out to prevent this stacking in order to increase the surface area, thereby being a more suitable material for the manufacture of electrodes for supercapacitors as its capacitance greatly depends on the electrode material. To solve this problem, the conversion of two-dimensional graphene sheets to three-dimensional crumpled graphene structure has been verified to be the most effective approach. The study of crumpled graphene has been one of the recent trends in the field of energy storage applications in consumer electronics and hybrid vehicles as the process of crumpling can be controlled to suit the prospective device applications.
5,400원
2.
2021.08
구독 인증기관 무료, 개인회원 유료
Carbon lives along with us in our daily life and has a vital role to play. It is present in the air and within all living organisms. Due to its handheld advantage in nano-properties that are utilized in many applications, carbon substrates came under limelight during the recent decades. Carbon substrates are most widely used in cancer detection, catalysis, bio-sensing, adsorption, drug delivery, carbon capture, hydrogen storage, and energy. Alongside, composite materials with carbon as an additive are also developing rapidly in applications like infrastructures, automobile, health care, consumer goods, etc. which became an integral chunk of our life. In this paper different types of carbon substrates and its applications, properties of the substrates were reviewed. The applications and methods of synthesis of carbon substrates are also dealt with a broad perspective.
6,100원
3.
2021.08
구독 인증기관 무료, 개인회원 유료
The simultaneous use of KOH and nitrogen to manufacture carbon materials provides these materials with properties that the presence of only one of these additives would not give them, such as high porosity and reactivity. However, it is difficult to obtain nitrogen-doped carbon materials with both high porosity and high nitrogen content, as the KOH significantly reduces the nitrogen content. In this review the complex relationships between nitrogen content and nitrogen precursor amount, KOH amount and the activation temperature are discussed, with a focus on the different N-functional groups and the porosity of the fabricated carbons. Generally, increasing activation temperature and increasing KOH amount decrease the nitrogen content due to reactions with the N-containing substructures of carbon, resulting in the release of nitrogen as N2, HCN and other N gases. Increasing these parameters can also result in the reduction of pyridine-N while the amount of quaternary-N increases simultaneously. Besides this, an increase in the amount of nitrogen precursor leads to an increase in the porosity of N-doped materials. However, too high amounts of the nitrogen precursor generate an excess of nitrogen which blocks the pore system and consequently reduces the porosity of the doped carbons.
4,300원
4.
2021.08
구독 인증기관 무료, 개인회원 유료
Highly Oriented Pyrolytic Graphite (HOPG) was half covered using aluminum foil and exposed to irradiation with 70 keV C+ ions at room temperature (~ 25 ℃). The surface layer (height = 178.3 ± 4.7 nm) of the irradiated area was destroyed, many nano-sized dendritic protrusions were observed and smooth inner layer was exposed. The peak area ratio (ID/IG) in Raman spectra increased after ion irradiation, indicating that a change in atomic structure and transformation from the sp2 to sp3 phase. The mechanical properties were explored using atomic force microscopy in peakforce mode, which revealed that the Young’s modulus of the exposed inner layer was similar to unirradiated area, while the Young’s modulus of the dendritic protrusions was higher. There findings provided further understanding of the HOPG at nanoscale, which is of value for practical implementation in related fields.
4,000원
5.
2021.08
구독 인증기관 무료, 개인회원 유료
Erman Taer, Friska Febriyanti, Widya Sinta Mustika, Rika Taslim, Agustino Agustino, Apriwandi Apriwandi
A carbon nanofiber was produced from the Areca catechu husk as a supercapacitor electrode, utilizing a chemical activation of potassium hydroxide (KOH) at different concentrations. One-stage integrated pyrolysis both carbonization and physical activation were employed for directly converting biomass to activated carbon nanofiber. The morphology structure, specific surface area, pore structure characteristic, crystallinity, and surface compound were characterized to evaluate the influence on electrochemical performance. The electrochemical performance of the supercapacitor was measured using cyclic voltammetry (CV) through a symmetrical system in 1 M H2SO4. The results show that the KOH-assisted or absence activation converts activated carbon from aggregate into a unique structure of nanofiber. The optimized carbon nanofiber showed the large specific surface area of 838.64 m2 g−1 with the total pore volume of 0.448 cm3 g−1, for enhancing electrochemical performance. Beneficial form its unique structural advantages, the optimized carbon nanofiber exhibits high electrochemical performance, including a specific capacitance of 181.96 F g−1 and maximum energy density of 25.27 Wh kg−1 for the power density of 91.07 W kg−1. This study examines a facile conventional route for producing carbon nanofiber from biomass Areca catechu husk in economical and efficient for electrode supercapacitor.
4,300원
6.
2021.08
구독 인증기관 무료, 개인회원 유료
Graphene fiber is considered as a potential material for wearable applications owing to its lightness, flexibility, and high electrical conductivity. After the graphene oxide (GO) solution in the liquid crystal state is assembled into GO fiber through wet spinning, the reduced graphene oxide (rGO) fiber is obtained through a reduction process. In order to further improve the electrical conductivity, herein, we report N, P, and S doped rGO fibers through a facile vacuum diffusion process. The precursors of heteroatoms such as melamine, red phosphorus, and sulfur powders were used through a vacuum diffusion process. The resulting N, P, and S doped rGO fibers with atomic% of 6.52, 4.43 and 2.06% achieved the higher electrical conductivities compared to that of rGO fiber while preserving the fibrious morphology. In particular, N doped rGO fiber achieved the highest conductivity of 1.11 × 104 S m−1, which is 2.44 times greater than that of pristine rGO fiber. The heteroatom doping of rGO fiber through a vacuum diffusion process is facile to improve the electrical conductivity while maintaining the original structure.
4,000원
7.
2021.08
구독 인증기관 무료, 개인회원 유료
Most recently, graphene-related composite-modified electrode surfaces are been widely employed to improve surface interactions and electron transfer kinetics. Hydrothermally prepared strontium pyro niobate (SPN) and reduced graphene oxide/ strontium pyro niobate (RGOSPN) nanostructures reveal excellent morphology. X-ray diffraction analysis of SPN and RGOSPN agree with standard data. Thermogravimetry–differential scanning calorimetry analyses show that RGOSPN has higher thermal stability than SPN. In addition, from the polarization–electric field (P–E) loop measurements, the estimated value of remnant polarization (Pr) and coercive electric field (Ec) of SPN are 0.039 μC cm−2 and − 2.90 kV cm−1 and that of RGOSPN nanocomposite are 0.0139 μC cm−2 and − 2.04 kV cm−1. Cyclic voltammetry measurements show that RGOSPN nanocomposite manifests the possibility of electrochemical reversibility beyond long cycles without change in performance. The redox cycle reveal that RGOSPN can be used as part of a composite electrode for hybrid capacitors dynamic conditions. Moreover, the specific capacitance of SPN and RGOSPN was calculated using galvanostatic charge–discharge (GCD) technique. The observed energy density of 9.1 W h kg−1 in RGOSPN is higher when compared with previous reported values.
4,800원
8.
2021.08
구독 인증기관 무료, 개인회원 유료
Abstract In this study, we investigated that the activated carbon (AC)-based supercapacitor and introduced SIFSIX-3-Ni as a porous conducting additive to increase its electrochemical performances of AC/SIFSIX-3-Ni composite-based supercapacitor. The AC/SIFSIX-3-Ni composites are coated onto the aluminum substrate using the doctor blade method and conducted an ion-gel electrolyte to produce a symmetrical supercapacitor. The electrochemical properties of the AC/SIFSIX-3-Ni composite-based supercapacitor are evaluated through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge tests (GCD). The AC/SIFSIX-3-Ni composite-based supercapacitor showed reasonable capacitive behavior in various electrochemical measurements, including CV, EIS, and GCD. The highest specific capacitance of the AC/SIFSIX-3-Ni composite-based supercapacitor was 129 F g−1 at 20 mV s−1.
4,000원
9.
2021.08
구독 인증기관 무료, 개인회원 유료
Hierarchical porous carbons (HPCs) have been successfully prepared by a facile carbonization and subsequent CO2 activation process using corncob as a natural carbon precursor and Mg(C2H3O2)2 as a MgO nano-template precursor. The prepared corncob-based hierarchical porous carbons (C-HPCs) with desirable micropores and mesopores feature the excellent absorbency of gas (i.e., CO2 and CH4) and solution (i.e., methylene blue (MB)). Increasing the ratio of Mg(C2H3O2)2/corncob enlarged the specific surface area up to 1004 m2/ g, micropore and mesopore volumes, CO2, CH4, and MB adsorption capacities (112, 31 and 230 mg/g after 325 min, respectively). The results indicated that the pore structures of C-HPCs can be easily and suitably controlled by the amount of the template precursor and CO2 activation effecting concurrently, which leads to fascinating adsorption capacity for CO2, CH4, and MB.
4,200원
10.
2021.08
구독 인증기관 무료, 개인회원 유료
The adsorption of molecular hydrogen on the monolayer graphene sheet under varied temperature and pressure was studied using molecular dynamics simulations (MDS). A novel method for obtaining potential energy distributions (PEDs) of systems was developed to estimate the gravimetric density or weight percentage of hydrogen. The Tersoff and Lennard–Jones (LJ) potentials were used to describe interatomic interactions of carbon–carbon atoms in the graphene sheet and the interactions between graphene and hydrogen molecules, respectively. The results estimated by the use of novel method in conjunction with MDS developed herein were found to be in excellent agreement with the existing experimental results. The effect of pressure and temperature was studied on the adsorption energy and gravimetric density for hydrogen storage. In particular, we focused on hydrogen adsorption on graphene layer considering the respective low temperature and pressure in the range of 77–300 K and 1–10 MPa for gas storage purpose which indicate the combination of optimal extreme conditions. Adsorption isotherms were plotted at 77 K, 100 K, 200 K, and 300 K temperatures and up to 10 MPa pressure. The simulation results indicate that the reduction in temperature and increase in pressure favor the gravimetric density and adsorption energies. At 77 K and 10 MPa, the maximum gravimetric density of 6.71% was observed. Adsorption isotherms were also analyzed using Langmuir, Freundlich, Sips, Toth, and Fritz–Schlunder equations. Error analysis was performed for the determination of isotherm parameters using the sum of the squares of errors (SSE), the hybrid fractional error function (HYBRID), the average relative error (ARE), the Marquardt’s percent standard deviation (MPSD), and the sum of the absolute errors (SAE).
4,300원
11.
2021.08
구독 인증기관 무료, 개인회원 유료
The carbon spheres (CSs) synthesized by an ultrasonic-spray pyrolysis method were activated for supercapacitor electrode. There are plenty of cracks on the surface of the activated carbon spheres (ACSs), which expend with increasing the activation temperature and activator dosage. The specific capacitance of ACSs increases with the activation temperature and activator dosage and reach to maximal value at certain conditions. Importantly, the ACS sample activated at relatively low activation temperature (600 °C) and 7 of mass ratio of KOH to CSs has the highest specific capacitance (about 209 F g− 1 at 50 mA g− 1 of current density) and indicates the excellent cycling stability after 1000 consecutive charge–discharge cycles. Furthermore, the graphene sheets could be found in the samples that were activated at 1000 °C. And the electrode prepared by the sample has the very low series resistance because of the excellent conductivity of the formed graphene sheets.
4,000원
12.
2021.08
구독 인증기관 무료, 개인회원 유료
Carbon nanotube (CNT) grafted with hyperbranched poly(amidoamine) (PAMAM) dendrimer (CNTD) were used as a multifunctional curing and composite agent of polyurethane (PU) terminated with epoxy units. Amino-functionalized CNT was used as the core for grafting the first generation of PAMAM dendrimer by sequential addition of methyl acrylate and ethylenediamine. Two different epoxy-terminated PUs (PUB and PU-PMDA) were prepared from the reaction of poly(ethylene glycol), excess amounts of hexamethylene diisocyanate, and different chain extenders (1,4-butanediol for PUB and pyromellitic dianhydride (PMDA) for PU-PMDA), and subsequent end group transformation of the isocyanate groups to epoxy functionalities using glycidol. Fourier transform infrared spectra and thermogravimetric analysis (TGA) results showed that CNTD was successfully prepared. TGA thermograms revealed that thermal decomposition of composites were carried out in two main steps related to the soft and hard segments. In addition, char content and thermal stability of the composites were increased with increasing the CNTD content. Most importantly, the PMDA chain extender resulted in high thermal stability of the epoxy-terminated PU composites. X-ray diffraction and scanning and transmission electron microscopies presented morphological and structural properties of nanotubes and hybrid composites.
4,300원
13.
2021.08
구독 인증기관 무료, 개인회원 유료
Carbon nanotube (CNT) structures reported in the literature often have a black color with low reflectance and matt surface appearance. Only a few papers reported the high reflectance and glossy appearance of the CNT surface on a substrate. To our knowledge, no one has reported the glossy appearance of freestanding CNT. Herein, we have successfully fabricated a freestanding multi-walled CNT sheet with a glossy or mirror-like surface appearance. Raman spectroscopy confirmed that both matt and glossy freestanding CNT sheets have the same chemical composition. We found that the glossy freestanding CNT sheet has a relatively flat surface morphology compared to matt freestanding CNT sheet, as seen in the atomic force microscopy results. We attributed the glossy appearance due to a relatively flat surface morphology of the freestanding CNT sheet.
4,000원
14.
2021.08
구독 인증기관 무료, 개인회원 유료
Nitrogen-doped carbon dots (N-CDs), derived from the biomass (anthocyanin), are the novel additive to the nanocarbon materials, which is expected to bring a wide spectrum of novel applications. Moreover, metallic oxides are emerging for their unique potential for electrocatalysis. Herein, we report the synthesis of N-CDs for the selective detection of Fe3+ with a limit of detection of 2.57 μM in the range of 5–60 μM using ethylenediamine and H2O2 by a hydrothermal method. The obtained N-CDs displayed a spherical morphology with a particle size range of 2–7 nm and emitted blue luminescence at 394 nm under excitation at 319 nm. Meanwhile, we have demonstrated the fabrication of cost-efficient electrocatalysts for oxygen evolution reaction (OER) in an alkaline medium, employing N-CDs. Owing to the successful incorporation of N-CDs into NiO nanospheres, the resulting N-CDs/NiO with large surface areas, fast charge transfer, and increased conductivity vastly improved the catalytic activity. Remarkably, the optimal of N-CDs/NiO composite requires the overpotential of only 380 mV at a current density of 10 mA cm− 2 and a relatively low Tafel slope of 57.96 mV dec− 1 compared with pure NiO. These results open up a facile route for the application of N-CDs and offer prospects for CD-metal hybrids as high OER catalysts in electrochemical energy devices.
4,300원
15.
2021.08
구독 인증기관 무료, 개인회원 유료
C. A. Espinoza‑Moreno, M. Rodriguez‑Rodriguez, M. J. Pellegrini‑Cervantes, C. P. Barrios‑Durstewitz, R. E. Núñez‑Jaquez, H. J. Peinado‑Guevara, M. Chinchillas‑Chinchillas, G. Fajardo‑San‑Miguel
The use of recycled materials, such as the fine recycled aggregate made from concrete waste and carbon fiber (CF) product of industrial waste, for the manufacture of conductive recycled mortars (CRM), transforms the mortar base cement normally made with cement:sand in a sustainable multifunctional material, conferring satisfactory mechanical and electrical properties for non-structural uses. This action provides ecological benefits, reducing the use of natural fine aggregates from rivers and the amount of concrete waste deposited in landfills resulting from construction waste. In this investigation the effect of the addition of CF on electrical properties in hardened, wet and dry state, electric percolation in dry state and fluidity of the wet mixture of a cement based CRM was evaluated: fine recycled aggregate: graphite powder, CRM specimens with dimensions of 4 × 4 × 16 cm. were manufactured for 3, 7 and 28 days of age and sand/cement ratios = 1.00, graphite/cement = 1.00, water/cement = 0.60 and CF = 0.1, 0.3, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0% compared to the weight of cement. The results demonstrated the effect of the addition of CF in CRM, reducing fluidity of the mixtures due to the opposition generated by its physical interaction of CF with recycled sand or recycled fine aggregate and graphite powder (GP), in its case, placing the electric percolation percolation at 0.30% and 0.45% of CF for CRM with and without GP, respectively. Increases in electrical conductivity (EC) without the presence of GP are defined by the contact between the CF and the conductive paths formed. In contrast, with the presence of GP, the EC is defined by the contact between the CF and the GP simultaneously, forming conductive routes with greater performance in its EC.
4,600원
16.
2021.08
구독 인증기관 무료, 개인회원 유료
Spent Calgon Filtrasorb activated carbon (SAC) from glycerine deodorization unit was evaluated for the removal of methylene blue (MB). The SAC was used without further modification. The SAC was characterized for BET surface area, pH, pHpzc and FTIR to determine the textural and chemical properties of SAC. The batch adsorption study of MB was carried out under different initial concentrations (5–500 mg/L), pH (2–11) and contact time (0–200 h). The SAC was found to have high BET surface area, pore volume and average pore diameter of 735 m2/g, 0.292 cm3/g and 2.56 nm, respectively. The properties of SAC contributed to high MB adsorption capacity of 283 mg/g. The equilibrium data fitted well with Langmuir model, indicating monolayer adsorption; while the activation energy (Ea) of Dubinin–Radushkevitch (D–R) model is lower than 8 kJ/mol, signifying physisorption. The adsorption kinetics was best illustrated by pseudo-second-order model, while the intraparticle diffusion and Boyd models suggested that film diffusion is the rate-controlling step. These findings showed that Calgon Filtrasorb SAC from glycerine deodorization unit can be potentially reused an adsorbent for the removal of dyes.
4,000원
17.
2021.08
구독 인증기관 무료, 개인회원 유료
Shuaib Edakkaparamban, Muhammed Shafi Parasseri, Gaurav Kumar Yogesh, Chandra Bose Arumugam, Sastikumar Dillibabu
In this work, a simple nonenzymatic glucose sensor has been proposed based on coconut shell charcoal (CSC) modified nickel foil as working electrode in a three-electrode electrochemical cell. Charcoal was prepared by the pyrolysis of coconut shells. The most important advantages of coconut shells are cost-effectiveness and their abundance in nature. The morphology and phase of the CSC powder were characterized by scanning electron microscopy and X-ray diffraction. The electrochemical performance of the CSC powder coated Nickel foil electrode was investigated by cyclic voltammetry and chronoamperometry. The sensor shows a higher sensitivity of 2.992 mA cm−2 mM−1 in the linear range of 0.5–5.5 mM and slightly lower sensitivity of 1.1526 mA cm−2 mM−1 in the range of 7–18.5 mM glucose concentration with a detection limit of 0.2 mM. The anti-interference property of CSC powder also was investigated and found that the response of interfering species was less significant compared to glucose response. The proposed sensor offers good sensitivity, wide linear range, and a very low response to interfering biomolecules.
4,000원
18.
2021.08
구독 인증기관 무료, 개인회원 유료
Preparation of activated carbon from biomass residue with conventional steam activation was conducted to find the alternative raw materials for meeting the high demand for low-cost porous material in the desiccant application. In this study, activated carbons were produced from dead camphor leaves using two-step methods at different preparation temperatures. The characterization results revealed that the prepared activated carbons have a surface area of 700 m2/g, with 75% of microporosity. The water vapor sorption study reported that the water uptake of camphor leaf-based activated carbons was strongly affected by the pore properties of the materials. Moreover, from the water adsorption kinetics, it was observed that the rate constant of adsorption was varied at each relative pressure, which can be assumed that the water adsorption mechanism is different at each relative pressure. From these results, it was revealed that the prepared camphor leaf-based activated carbons have a promising ability to adsorb water vapor from humid air.
4,300원
19.
2021.08
구독 인증기관 무료, 개인회원 유료
The discharge of dye-containing industrial effluents such as methylene blue (MB) in water bodies has resulted in severe aquatic and human life problems. In addition to this factor, there is the accumulation of banana peel wastes, which can generate ecological damage. Thus, this research purpose a different method from the literature using the banana peel waste (BP) to produce activated carbon (ACBP) by NaOH activation followed by pyrolysis at 400 °C to remove methylene blue (MB). The material was characterized by TGA, XRD, SEM, BET, and FTIR. The influence of dye concentration (10, 25, 50, 100, 250, and 500 mg L−1) was investigated. ACBP presented a well-developed pore structure with a predominance of mesopores and macropores. This morphological structure directly influences the MB removal capacity. The highest efficiency for dye removal was in the MB initial concentration of 25 mg L−1, sorbent of 0.03 g, and contact time of 60 min, which were 99.8%. The adsorption isotherms were well defined by Langmuir, Freundlich, and Temkin isotherm models. The Langmuir model represented the best fit of experimental data for ACBP with a maximum adsorption capacity of 232.5 mg g−1. This adsorbent showed a comparatively high performance to some previous works. So, the banana peel waste is an efficient resource for producing activated carbon and the adsorption of methylene blue.
4,600원
20.
2021.08
구독 인증기관 무료, 개인회원 유료
G. S. Lekshmi, R. Tamilselvi, Karthika Prasad, Olha Bazaka, Igor Levchenko, Kateryna Bazaka, Mandhakini Mohandas
Oil spills into ocean or coastal waters can result in significant damage to the environment via pollution of aquatic ecosystems. Absorbents based on reduced graphene oxide (rGO) foams have the capacity to remove minor or major oil spills. However, conventional chemical synthesis of rGO often uses petrochemical precursors, potentially harmful chemicals, and requires special processing conditions that are expensive to maintain. In this work, an alternative cost-effective and environmentally friendly approach suitable for large-scale production of high-quality rGO directly from used cooking sunflower oil is discussed. Thus, produced flaky graphene structures are effective in absorbing used commercial sunflower oil and engine oil, via monolayer physisorption in the case of used sunflower and engine oils facilitated by van der Waals forces, π–π stacking and hydrophobic interactions, π-cation ( H+) stacking and radical scavenging activities. From adsorption kinetic models, first-order kinetics provides a better fit for used sunflower oil adsorption (R2 = 0.9919) and second-order kinetics provides a better fit for engine oil adsorption (R2 = 0.9823). From intra-particle diffusion model, R2 for USO is 0.9788 and EO is 0.9851, which indicates that both used sunflower and engine oils adsorption processes follow an intra-particle diffusion mechanism. This study confirms that waste-derived rGO could be used for environmental remediation.
4,800원
1
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