간행물
Carbon Letters KCI 등재 Carbon letters
- 발행기관 한국탄소학회
- 자료유형 학술지
- 간기 연7회
- ISSN 1976-4251 (Print)2233-4998 (Online)
- 수록기간 2000 ~ 2026
- 주제분류 자연과학 > 자연과학일반 자연과학 분류의 다른 간행물
- 십진분류KDC 530DDC 620
권호리스트/논문검색
Vol.35 No.5 (2025년 10월) 42건
21.
2025.10
구독 인증기관 무료, 개인회원 유료
Wenshuai Xi, Xiongchao Lin, Jingdong Yang, Caihong Wang, Yonggang Wang
The aromatization degree of coal liquefaction pitch is closely related to its molecular structure evolution and the properties of derived carbon fibers. Using refined coal direct liquefaction pitch (RCLP) as raw material, pitches with different aromatization degrees were prepared by the self-pressurization/N₂ blowing two-stage thermal condensation method. Carbon fibers were then produced through melt spinning, oxidative stabilization, and carbonization. As the aromatization degree advanced, the C/H atomic ratio rose from 1.55 to 2.01, with the mesophase content nearing 100%. During RCLP thermal polymerization, large toluene-insoluble molecules were readily generated, yet the enrichment of the mesophase was comparatively sluggish. The spinnable pitch from RCLP had a relatively high aliphatic hydrogen content (33.40% ~ 13.69%) and a lower aromaticity (91.62% ~ 96.90%). Increasing aromatization made the carbon fiber cross-section’s radial transverse texture more distinct and ordered. The carbon layers stacked closely and parallelly, leading to a continuously rising tensile modulus. Due to the inhomogeneity from isotropic and anisotropic component changes, the carbon fiber tensile strength first decreased and then increased. When the spinnable pitch C/H ratio was 1.84, the mesophase pitch-based carbon fiber had an average diameter of 14.78 μm, a tensile strength of 1140 MPa, and a tensile modulus of 209 GPa.
4,500원
22.
2025.10
구독 인증기관 무료, 개인회원 유료
Nan Wang, Yihang Wei, Hejia Sun, Ning Wang, Yonghong Liu, Yunfeng Li
The adsorption of a single pollutant can no longer meet the increasingly strict requirements of environmental governance. The easy loss and secondary pollution of powdered adsorbents further hinder the industrialization of adsorption technology. Through in-situ oxidative polymerization and hydrothermal deposition, polyaniline (PANI) and magnetic Fe3O4 nanoparticles were loaded onto a polyurethane (PU) matrix to prepare polyurethane-polyaniline /Fe3O4 (PU-P/F) porous composite loading materials, aiming to simultaneously remove multiple pollutants in wastewater and solve the problem of effective solid– liquid separation at the same time. The synthesized composite material exhibited a high specific surface area (30.08 m2/ g) and a hierarchical pore structure. Within a wide pH range (5–7), it showed a synchronous adsorption and removal effect on typical pollutants (ARG, Cr (VI), NO3 −-N, TP, MB, NH4 +-N) in printing and dyeing wastewater. Equilibrium can be reached within 0.5–2 h, following pseudo-second-order kinetics and Langmuir isotherm model, indicating mainly monolayer chemical adsorption. The continuous column adsorption regeneration test showed that for the simulated mixed wastewater, the continuous adsorption reached saturation after 660 min (53 chromatographic columns), while for the actual wastewater, the continuous column adsorption reached saturation after 535 min (43 chromatographic columns), and the efficiency remains after 8 regenerations. FT-IR and XPS confirmed the REDOX reaction between the –NH—group in polyaniline and Fe in Fe3O4, facilitating the adsorption and transformation of pollutants, while DFT calculations confirmed the strong interaction between polyaniline and anionic pollutants. This research provides ideas for solving the engineering bottleneck of adsorption technology.
5,100원
23.
2025.10
구독 인증기관 무료, 개인회원 유료
Jun Zhang, Wei Wang, Yue Yang, Yan Yan, Yongsheng Yan, Zhi Zhu
Photocatalytic reduction of CO2 into fuels offers a promising avenue to tackle present energy challenges and mitigate global warming. At present, TiO2 has been widely used in photocatalytic CO2 reduction reactions, and element doping can optimize the band structure of TiO2 to improve the efficiency of photocatalytic CO2 reduction. In this work, TiO2 doped with different content of N was prepared using TiN as the precursor through a simple one-step calcination method. Under optimized conditions, the optimal CO yield of the modified photocatalyst is 41.1 μmol g− 1 h− 1, which is 8 times higher than that of p25 type TiO2. Density functional theory (DFT) calculations confirmed that N-doping can reduce the band gap of TiO2 and decrease the Gibbs free energy of CO2 reduction reaction. In-situ-XPS indicated that N-doping can enhance the activation of CO2 by enriching photo generated electrons. Additionally, In-situ-FTIR spectra were employed to detect intermediates and track variations in the consumption of H2O and CO2, providing deeper insights into the mechanism responsible for enhancing efficiency. Our work addresses the deficiencies of the past and provides more detailed theoretical insights for the accelerated photocatalytic reduction of CO2 by N-doping TiO2.
4,300원
24.
2025.10
구독 인증기관 무료, 개인회원 유료
Yuchun Huan, Yue Dong, Junping Wang, Jin Bai, Huilong Tao, Min Wang
The composite of CVD-grown Gr is a promising method for improving the electrical properties of Cu-based microscale materials. Almost all of the previous works focused on the CVD-grown continuous Gr. However, after the combination with surface of Cu substrate, the continuous Gr is prone to fracture or peeling when it is bent under strain in practical applications with low bending stability, leading to a decrease in its conductivity. In this study, significantly enhanced electrical properties and bending stability are demonstrated by synthesizing CVD-grown Gr sheets layers on microscale-diameter Cu wires, including 10.9% higher electrical conductivity and 7.9% higher maximum current density compared to commercial pristine Cu wires. After the test of bending cycles, Gr sheets/Cu wires exhibit extraordinary bending stability, with less than 1.3% conductivity changes for wires. In contrast, the continuous Gr/Cu wires show poor bending stability with a nearly 10% reduction in conductivity. Hence, the Gr sheets/Cu wires have significant advantages in practical applications.
4,300원
25.
2025.10
구독 인증기관 무료, 개인회원 유료
Zi Hu, Jundong Meng, Xinyuan Xu, Liuyun Chen, Xuan Luo, Xinling Xie, Zuzeng Qin, Tongming Su
Combining CuPc with semiconductor materials as organic‒inorganic hybrid photocatalysts can effectively improve the light absorption capacity and separation efficiency of photogenerated electrons and holes in semiconductor photocatalysts. Herein, a CuPc/Bi2WO6 Z-scheme heterojunction was successfully designed and used for CO2 photoreduction. The separation of photogenerated electrons and holes is greatly enhanced because of the formation of a compact organic‒inorganic heterointerface and the built-in electric field between CuPc and Bi2WO6, which increases the photocatalytic CO2 reduction efficiency. Moreover, the photosensitizer CuPc can effectively enhance the light absorption of Bi2WO6. The optimal 1CuPc/ Bi2WO6 composite exhibits the best photocatalytic performance, with a CO production rate of 2.95 μmol g− l h− 1, which is three times greater than that of Bi2WO6 under visible-light irradiation. This work provides a new idea for the construction of an organic‒inorganic photocatalytic system for CO2 reduction.
4,600원
26.
2025.10
구독 인증기관 무료, 개인회원 유료
Boopathi Shagunthala Hariprasad, Jagadeesh Likhith, Senthilkumar Aravind, Sreenidhi M Varma, Kasirajan Prakash, Sundaram Ganesh Babu
The combination of copper and cobalt in the mixed metal oxides phase attracted considerable interest owing to their distinct characteristics and wide-ranging applications across various domains. In this study, we adopt a facile co-precipitation approach to prepare the hollow carbon spheres (HCSs) embedded with CuCo2O4 nanoparticles to enhance the catalytic activity. HCSs are prepared using a hydrothermal template method followed by the removal of the silica template. The resulting CuCo2O4 and HCSs are characterized by using X-ray diffraction, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, and Thermo-Gravimetric Analysis to ensure structural integrity and composition. Then, the CuCo2O4 nanoparticle is doped on the porous structure of HCSs using a surface loading method and used as a catalyst for the transfer hydrogenation of acetophenone. The scope is extended using various substrates without a hydrogen source. This nano-catalytic system shows better yields in mild reaction conditions. There was no leaching of the material into the reaction system even after five cycles, thus confirmed by ICP-MS.
4,800원
27.
2025.10
구독 인증기관 무료, 개인회원 유료
A. M. Nima, Sariga C. Lal, Subodh Ganesanpotti
Designing long-wavelength emissive carbon dots (CDs) with high photoluminescence quantum yield (PL QY) is an inevitable component for lighting applications. However, it is still challenging to develop an efficient CDs with excitation-independent emission in long-wavelength regions. In this work, we developed an excitation-independent yellow emissive CD (y-CDs) with PL emission centered at 568 nm via a facile solvothermal treatment of citric acid and melamine using toluene as solvent. The synthesized, y-CDs contain a high degree of conjugated sp2- carbon domains (fused rings) with different surface groups, which serve as a center for photon absorption. The addition of melamine improves the degree of sp2- conjugated carbon domain and surface groups thereby switching the emission of y-CDs from excitation-dependent to excitation-independent emission with excellent PL QY of 80.2%, UV stability, and large Stoke shift. This work not only developed an efficient yellow emissive CD but also explored the possible mechanism of excitation-independent emission and used it for the development of phosphor-converted LEDs. The LED shows warm yellow light with CIE coordinates of (0.48, 0.49), CCT of 2983 K, excellent color purity of 94%, and high thermal stability. This study promotes the development of cost-effective and ecofriendly optoelectronic devices for smooth lighting applications.
5,200원
28.
2025.10
구독 인증기관 무료, 개인회원 유료
Xue Du, Tong Han, Biao Jin, Long‑Yue Meng, Lian‑Hua Han
Contamination of food with heavy metal ions and nitrites poses a serious threat to human health. Consequently, the development of fast and sensitive platforms for detecting these contaminants is urgently required. In this paper, a novel MnMgFe- LDHs/DC sensor is constructed based on a simple strategy, in which MnMgFe layered double hydroxide (LDHs) is used as a metal precursor, and a unique "island bridge" carbon network structure is generated by its pyrolysis with ZIF-8@B, N-WMCNTs. The electrical conductivity was enhanced, and a large electroactive surface area was provided for the MnMgFe- LDHs/DC. The electrochemical properties of Pb2+, Cd2+ and nitrite were investigated using this electrode as a working electrode. Under optimized conditions, the sensing platform exhibited a wide linear range with the Pb2+, Cd2+, and NO2 − limits of detection of 46.16 nM, 59.25 nM, and 0.083 μM, respectively. Of particular note is that this sensing platform exhibits outstanding anti-interference capabilities. It can precisely and efficiently conduct the detection of nitrite and heavy metal ions in pickled foods.
4,200원
29.
2025.10
구독 인증기관 무료, 개인회원 유료
Dong Yeong Kim, Hokyun Rho, Eunyoung Lee, Junwoo Kim, Sukang Bae, Tae‑Wook Kim, Sang Hyun Lee
The distinctive surface characteristics of two-dimensional(2D) materials present a significant challenge when developing heterostructures for electronic or optoelectronic devices. In this study, we present a method for fabricating top-gate graphene field-effect transistors (FETs) by incorporating a metal interlayer between the dielectric and graphene. The deposition of an ultrathin Ti layer facilitates the formation of a uniform HfO₂ layer on the graphene surface via atomic layer deposition (ALD). During the ALD process, the Ti layer oxidizes to TiO₂, which has a negligible impact on the current flow along the graphene channel. The mobility of graphene in the FET was enhanced in relation to the SiO₂-based back-gate FET by modifying the thin HfO₂ top-gate dielectric deposited on the Ti interlayer. Furthermore, shifts in the Dirac point and subthreshold swing were markedly reduced owing to the reduction in charge scattering caused by the presence of trap sites at the interface between graphene and SiO₂. This route to modulating the interface between 2D material-based heterostructures will provide an opportunity to improve the performance and stability of 2D electronics and optoelectronics.
4,000원
30.
2025.10
구독 인증기관 무료, 개인회원 유료
M. V. Il‵ina, O. I. Soboleva, M. R. Polyvianova, N. N. Rudyk, I. V. Pankov, D. N. Khomlenko, O. I. Il‵in
This study presents, for the first time, a piezoelectric nanogenerators (PENG) model based on the nitrogen-doped carbon nanotubes (N-CNTs) array and demonstrates the ability of N-CNT to convert external oscillations into electrical energy. Molybdenum was proved to be a preferred material for the upper electrode due to its high corrosion resistance and the formation of ohmic contact at the interface with N-CNT. It was shown the operation of the PENG model in constant and pulsed modes. It was found that the output voltage of the PENG model increased linearly from 3 to 60 mV with an increase in the amplitude of the external mechanical influence from 3.5 to 95 μm and decreased from 54 to 26 mV with an increase in the frequency of external influence from 15 to 120 Hz due to an excess of the natural resonant frequency of the nanotubes. The experiments demonstrated that the power density of the N-CNT-based PENG model reached 12.63 μV/cm2. It was exhibited that the PENG model can be used not only as a nanogenerator for autonomous power supply of wearable electronic devices, but also as a highly sensitive deformation sensor. In addition, the clamping force of the upper electrode determines the frequency range of the PENG model. The obtained results open wide opportunities for practical application of vertically aligned N-CNTs for autonomous power supply of wearable electronic devices.
4,200원
31.
2025.10
구독 인증기관 무료, 개인회원 유료
Jun Ma, Shen Zhu, Xueli Wu, Xun He, Weiyi Wang, Juan Li, Cheng Yang, Yanli Liu, Chuanjun Tu
The constituents of coal tar pitch (CTP) significantly impact the wettability of calcined coke (CC) and the performance of prebaked anodes (PA) used in aluminum electrolysis. However, balancing wettability and carbon residue within CTP remains a central challenge in material applications. In addition, limited pore permeability and structural stability in these composites hinder the effective utilization of PA. Enhancing CTP fluidity is crucial for overcoming these challenges. In this work, a novel method was developed to modify CTP utilizing various coal tar fractions, enabling controlled modulation of CTP composition and wettability. Incorporating different fractions allowed for substantial control over interfacial bonding and pore structure. The chemical composition, functional groups, and elemental content of the CTP were analyzed via X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and proton nuclear magnetic resonance (1H NMR). Subsequently, systematic comparisons of PA materials produced from different CTP formulations demonstrated improved wettability and enhanced mechanical properties. Moreover, DFT calculations were performed to compare the adsorption energies of small molecules from different coal tar fractions with coke, reflecting the interaction strength between the molecules and the solid surface. Using micro-computed tomography (μ-CT), the refined pore structure was examined, resulting in a PA composite with an optimized balance of high strength and toughness.
4,900원
32.
2025.10
구독 인증기관 무료, 개인회원 유료
Yulei Qiao, Hang Chen, Sihan Liu, Anqi Xia, Yeshun Tian, Changliang Wu, Xiuzhi Zhang, Shuxia Feng, Xiao Xia, Liqiang Zhang, Guangbin Duan
To explore the heating characteristics of activated carbon in a microwave field, the effects of microwave irradiation power, the radius and physical properties of activated carbon, and a symmetrical waveguide on the heating characteristics of activated carbon in a microwave field were studied by experiments and simulation. This study distinguishes itself from previous works by focusing on high-power microwave heating (up to 800 W) and providing a comprehensive analysis of key parameters such as radius, thermal conductivity, magnetic conductivity, and dielectric constant. Additionally, the use of symmetrical waveguides and their impact on heating efficiency represents a novel contribution to the field of microwave-assisted flue gas desulfurization. According to the results, with the increase in microwave irradiation power, the heating rate of activated carbon in the microwave field increases, and the final temperature also rises. Waveguides significantly influence the heating characteristics of activated carbon. When multiple waveguides act on the same microwave field, electromagnetic waves interfere with each other and affect the distribution and intensity of the electromagnetic field. With an increase in the imaginary part of the relative permittivity, the real part of the relative magnetic permeability, and the thermal conductivity of the heated material, the heating characteristics of activated carbon in the microwave field are improved. This study provides a theoretical model for the heating characteristics and temperature distribution of activated carbon in a microwave field under high irradiation power.
4,600원
33.
2025.10
구독 인증기관 무료, 개인회원 유료
M. Jafarypouria, B. Mahato, S. G. Abaimov
This research presents a single-walled carbon nanotube (SWCNT)-enabled real-time monitoring system to optimize postcuring conditions (temperature and duration) for epoxy resin. This method can serve as an alternative to traditional methods like Differential Scanning Calorimetry (DSC), which is effective in measuring the degree of cure in polymers during industrial curing (manufacturer-recommended cure cycle). Two different programs using SWCNTs were employed to design the cure cycles for investigating the development of mechanical properties: Program A as the comparison of effects of varied duration of high-temperature curing and Program B as high-temperature curing followed by the varied duration of low-temperature post-curing. By correlating variation in the electrical resistance of SWCNT with curing stages, we illustrate that extending post-curing at 100 °C for 24 h after an initial 3-h cure at 130 °C increases (i) tensile strength by 60% and ultimate tensile elongation by 101% and (ii) shear strength by 14% and ultimate shear elongation by 16% compared to industry standards. This approach not only improves mechanical performance but also enables precise, non-destructive cure-state detection, offering a scalable solution for high-performance composites in the aerospace and automotive sectors.
4,800원
34.
2025.10
구독 인증기관 무료, 개인회원 유료
Young‑Soon Kim, Seung‑Kon Ryu, Kiseon Lee, Hyun Cho, Dong‑Wha Ryu, Hong‑Gun Kim, Lee‑Ku Kwac
Bamboo charcoal has high ecological and economic value, and is a sustainable and valuable resource for the development of advanced materials such as supercapacitors and batteries. The carbon content in bamboo-based white charcoal produced in traditional Korean kiln reaches 100% when the charcoals heat treated up to 2400℃. X-ray diffraction shows that graphite begins to form at 1500℃, becomes more pronounced at 1800℃, and crystallizes into a dense turbostratic structure at 2000℃. At 2400℃, discrete graphite peaks are confirmed in d002 and d100 planes, while carbon isotope peaks disappear. Raman spectroscopy shows that graphite crystals form at 1800℃, as indicated by a clear 2D band at 2680 cm⁻1. At 2400℃, the height of the D band at 1350 cm⁻1 is lower than that of the G band at 1580 cm⁻1, indicating a high degree of graphitization. The isothermal nitrogen adsorption–desorption curves show that the monolayer value of the sample decreases up to 1300℃, accompanied by a low-pressure hysteresis phenomenon. When heat-treated at 1500℃ or higher, this phenomenon disappears and the monolayer value decreases significantly, indicating the disappearance of micropores and occurrence of graphitization. After 10 min. of heat treatment at 2400℃, the specific surface area of the graphitized charcoal becomes 8.45 m2/ g, similar to that of artificial graphite, which shows promising results of 217 mAh/g at a current density of 0.02 A/g for using in Lithium ion battery electrode.
4,800원
35.
2025.10
구독 인증기관 무료, 개인회원 유료
Hyeon‑Hye Kim, Ju‑Hwan Kim, Jin‑Soo Jeong, Hye‑Min Lee, Kay‑Hyeok An, Byung‑Joo Kim
Electric double-layer capacitors (EDLCs) have attracted significant interest as a promising energy storage solution because of their high-power density, exceptional charge/discharge cycle stability, and extended lifespan. Porous carbon is a key component of EDLCs given its outstanding chemical stability, high electrical conductivity, large specific surface area, and cost effectiveness. We fabricated porous carbon from oak wood as a raw material using an environment-friendly steam activation process (physical activation). Pretreatment (stabilization) was conducted using a mild acid (phosphoric acid) to achieve a high specific surface area and maintain structural stability. Oak wood-derived porous carbon (Oak-PC) produced with varying activation times following phosphate stabilization achieved high specific surface area (1050–1990 m2/ g), pore volume (0.44–0.95 cm3/ g), and carbonization yield (36%). Oak-PC retained ~ 90% of its performance at a high current density (10 A/g), demonstrating superior EDLC performance compared to that of commercial porous carbon. These results were attributed to the significant enhancement of the electrical properties of Oak-PCs, achieved by removing char through phosphate stabilization and strengthening bond stability. This study provides foundational data for developing sustainable energy storage technologies and enhancing the efficiency of next-generation energy storage systems by utilizing environmentfriendly biomass materials such as oak wood.
4,600원
36.
2025.10
구독 인증기관 무료, 개인회원 유료
F. S. Abd El‑kawy, S. Hammad, H. Talaat, G. Bacher, M. Ghali
The avenue to synthesize eco-friendly and high-performing warm-white light emitting diodes (WLEDs) using quantum-dots for color conversion is challenging. Here, the graphene quantum dots (GQDs) are synthesized from Moringa oleifera leaves without the need of any organic solvents or reducing agents by a one-pot hydrothermal method and utilized for the design of efficient warm WLEDs. The photoluminescence of the obtained GQDs is found to be red-shifted as the excitation wavelength increases. This is ascribed to an excitation of multiple transitions due to various surface traps related to surface amino and oxygen functionalized groups as revealed from X-ray-photoelectron–spectroscopy and FTIR results. Three different concentrations of GQDs are embedded in polyvinyl-alcohol matrix acting as color-converters for the design of WLED devices. By increasing the GQDs concentration, the color correlated temperatures are tuned from 3804 to 2593 K and the luminous efficacy from 39.3 to 71.69 lm/W. Moreover, the chromaticity coordinates of the devices are shifted from (0.3825, 0.3665) to (0.4807, 0.4478). The brightness of the fabricated devices based on these green-GQDs are comparable with those of warm LEDs prepared from chemically synthesized graphene and carbon dots and can be suitable for indoor lighting applications.
4,900원
37.
2025.10
구독 인증기관 무료, 개인회원 유료
Jong Yoon Lee, Seung‑chul Choi, Dae Soon Im, Mansu Kim, Han‑Ik Joh
Developing highly durable and active catalysts is essential for improving the performance and longevity of proton exchange membrane fuel cells (PEMFCs). In this study, we propose a novel strategy to enhance catalyst dispersion and stability by incorporating pyrrolic nitrogen-rich carbon (pNC) quantum dots into highly crystalline carbon supports. The introduction of pNC generates strong anchoring sites for Pt nanoparticles, facilitating uniform dispersion and minimizing aggregation, which are key factors in enhancing catalytic performance and durability. The synthesized Pt/CVC150 catalyst exhibited excellent oxygen reduction reaction activity, with a half-wave potential of 0.842 V and a limiting current density of 6.3 mA cm− 2. Under accelerated stress test conditions, the catalyst retained 61.4% of its initial peak power density after prolonged cycling, indicating enhanced durability. Furthermore, single cell testing confirmed its improved electrochemical activity and stability of the Pt/CVC150 catalyst in a practical PEMFC operating environment. These findings suggest that the incorporation of heteroatom-doped carbon moieties onto carbon supports represents a promising strategy for the development of nextgeneration PEMFC catalysts with enhanced performance and longevity.
4,200원
38.
2025.10
구독 인증기관 무료, 개인회원 유료
Ru Chen, Guangtai Zhao, Xinmiao Cao, Wenxuan Wang, Yunxiang Xiao, Simeng Tian, Jize Dong
Currently, carbon nanotubes (CNTs) paper (also called Buckypaper, BP) is highly promising for application in flexible electronic materials. However, the lack of flexibility and durability of BP greatly affects the comprehensive performance. Here, we propose a simple method for manufacturing a waterborne polyurethane (WPU) toughened carbon nanotube paper (WPU-BP) with excellent overall performance through vacuum filtration. In WPU-BP, as the content of WPU increased from 0 to 48.3%, the tensile strength increased from 8.08 to 16.25 MPa, and the elongation at break increased from 2.14 to 225.04%, while the conductivity decreased from 41.34 to 20.33 S/cm. The WPU-BP with the WPU content of 18.9% (CNP8) demonstrated the optimum strain sensing performance. The gauge factor of CNP8 can reach 8.57 with a response time of 145 ms. It can detect a wide range of body movements from large joint movements to slight breathing, and exhibits high stability, maintaining high stability even after 1000 cycles. In addition, CNP8 shows excellent Joule heating performance, it can reach 186.1 °C at 5 V, with heating and cooling times of only 16 and 18 s, respectively, as well as with good reproducibility. In a word, the as-prepared WPU-BP exhibits excellent both strain sensing performance and Joule heating effect, and holds significant potential for applications in heating devices and wearable sensors.
4,300원
39.
2025.10
구독 인증기관 무료, 개인회원 유료
Xuechun Li, Desheng Xu, Yun Jin, Tingting Du, Jian Song, Yuxin Wei, Xiuxia Meng, Naitao Yang
Covalent organic framework (COF) membranes have emerged as promising candidates for hydrogen purification due to their tunable pore sizes and robust structures. However, achieving high selectivity and permeability simultaneously remains a challenge due to the inherent pore size distribution of COF materials. In this study, we fabricated two distinct COF membranes, TpPa-1 and TpTGCl, with pore sizes of 1.8 nm and 0.39 nm, respectively, using tailored synthesis methods. The TpTGCl membrane, synthesized via room temperature interfacial polymerization and vacuum-assisted filtration, exhibits an ultrathin nanosheet structure with an interlayer π–π stacking distance of 0.33 nm. This unique architecture, combined with its affinity for CO2 adsorption, enables exceptional hydrogen separation performance, achieving a H2/ CO2 selectivity of 52.5 and a H2 permeability of 3.49 × 10– 7 mol m− 2 s− 1 Pa− 1. Molecular dynamics simulations confirmed the steric hindrance effect as the primary mechanism for the selective permeation of hydrogen. The TpTGCl membrane effectively sieves larger gas molecules ( CO2, N2, CH4, etc.) without the need for material modification or excessive membrane thickness. This study demonstrates the potential of COF membranes with tailored pore sizes for high-performance hydrogen purification and offers valuable insights for the development of advanced separation technologies.
4,300원
40.
2025.10
구독 인증기관 무료, 개인회원 유료
Xianfei Xie, Sheng Wang, Danqiang Huang, Jianfeng Dai, Qing Wang
Structural design and element doping are the research hotspots in the preparation of lightweight absorbers with high absorption performance and low filling rate. This study employs different temperature carbonization and etching techniques to prepare the structure of hollow nitrogen-doped carbon flowers (HNC) and evaluate their microwave absorption performance. At an ultra-low filler loading of 5 wt.%, the microwave absorption intensity of HNC-800 remains stable at -50 dB with a thickness of 3.2 mm. It is noteworthy that the HNC-800 achieved the broadest effective absorption frequency band at a matching thickness of 2 mm, with a bandwidth of 5.36 GHz (ranging from 12.4 to 17.76 GHz). Such remarkable broadband and reflection loss performance can be attributed to the synergistic effects of the hollow porous network structure, interface polarization, and dipole relaxation mechanisms. More significantly, the reduction of the radar cross-section (RCS) amounts to as much as 31.67 dB m2, and it has been attested to possess excellent adsorption efficacy in practical application scenarios. HNC-800, as an absorbing material, holds potential for broad application prospects.
4,300원
