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.6 (2025년 12월) 43건
21.
2025.12
구독 인증기관 무료, 개인회원 유료
Yuhan Xia, Fangni Zhu, Song Guan, Sen Dou, Bowen Zhang, Wenjing Zhu
Microorganisms perform a crucial function in the biogeochemical processes that maintain soil quality. Nonetheless, the influence of biochar on soil microbial communities and their ecological functions remains poorly understood in black soils. To investigate this, a 2-year field experiment was conducted with four biochar application treatments: 0 t ha− 1 (CK), 6 t ha− 1 (BC6), 12 t ha− 1 (BC12), and 24 t ha− 1 (BC24). Microbial diversity and community composition under each treatment were assessed using high-throughput sequencing techniques. PICRUSt2 and FUNGuild were employed to predict microbial functional profiles. Compared to the control (CK), biochar addition led to notable shifts in both bacterial and fungal community structures. It also significantly enhanced bacterial α-diversity, as reflected by increased Shannon index, OTU counts, and Chao1 richness. However, a gradual decline in bacterial diversity was observed with rising biochar application rates. Taxonomic analysis revealed that biochar treatment significantly elevated the relative abundances of specific bacterial groups—such as Acidobacteria, Chloroflexi, Candidatus_Solibacter, and Bryobacter—as well as fungal groups such as Ascomycota, Zygomycota, Mortierella, Penicillium, and Fusarium. These effects were most evident under the moderate application rate (BC6). These microbial community changes may contribute to maintaining agroecological functions and soil health in biochar-amended soils. Regarding ecological functions, biochar application enhanced soil bacterial metabolic potential and saprotrophic fungal abundance, with more significant effects in the BC6 treatment, while reducing plant pathogenic fungi. This suggests beneficial effects on soil health maintenance and elemental cycling. Therefore, from the perspective of soil microbial community characteristics, biochar application positively influences black soil quality improvement. Considering environmental and economic benefits, a lower biochar application rate (6 t ha⁻1) may represent an optimal strategy for carbon sequestration, soil quality enhancement, and agroecological function maintenance in the studied system.
5,200원
22.
2025.12
구독 인증기관 무료, 개인회원 유료
Meng Wang, Tong Xu, Hong Pan, Lihui Xu, Yi Teng, Xueqiang Fu, Rui Zhang, Qian Li
In this study, a composite material based on agricultural waste coconut shells was successfully developed as an efficient, lightweight, and sustainable electromagnetic wave (EMW) absorber. Specifically, coconut shells were used as the raw material, and a simple one-step activation charring process was employed to obtain coconut shell porous carbon (CSPC). ZnFe2O4 with a hollow spherical structure was then in situ grown on the surface of CSPC, resulting in a special ZnFe2O4/ CSPC composite material. Due to its unique hollow structure, porous characteristics, and heterogeneous interfaces, the composite material achieved optimized impedance matching, leading to excellent EMW absorption performance. The fabricated ZnFe2O4/ CSPC composite demonstrated a minimum reflection loss ( RLmin) of − 37.32 dB at 10.80 GHz and an effective absorption bandwidth of 2.40 GHz at a thickness of only 2.0 mm. SEM and TEM analyses confirmed that the composite possessed a hollow and porous structure, while the BET specific surface area was measured at 133.709 m2 g⁻1. Based on the synergistic effects of ZnFe2O4 and CSPC, dielectric losses, magnetic losses, and impedance matching, the potential EMW absorption mechanisms were proposed. The ZnFe2O4/ CSPC composite material prepared in this study was a novel, green, and sustainable EMW absorber.
4,300원
23.
2025.12
구독 인증기관 무료, 개인회원 유료
Pengfei Deng, Shuangquan Wang, Qiuxue Zhang, Songsong Li, Yunjiao Deng, Zhongyu Fu, Chao Zhou, Huixuan Zhang
Poor bonding occurs with resin due to surface inertness of carbon fiber (CF), so CF surfaces were often treated. In some common surface treatments, sizing was a simple and effective modification method. Polyurethane (PU) was used as the main component of sizing agents due to its similar structure to polyamide 6 (PA6). The CF/PA6 composites’ interfacial properties were improved using PU as a sizing agent. Meanwhile, in this paper, glycidol (GLD) was introduced into the PU emulsion so that the epoxy group reacted with the carboxyl group on the acidified CF. After testing, when the content of glycidyl in the sizing agent is 2%, the CF/PA6 composites showed an important improvement in tensile, impact, and flexural strengths, which increased by 49.4%, 94.6%, and 53.2%, respectively. In addition, the effect of modified WPU sizing agents with different GLD contents on the properties of CF/PA6 composites was investigated.
4,000원
24.
2025.12
구독 인증기관 무료, 개인회원 유료
So Youn Mun, Jinuk Hwang, Da Hyun Yu, So Jung Baek, Dho Hyun Um, Dong Gi Seong, Kwang Youn Cho
Graphite crystals consist of a layered structure with stacked graphene sheets, and exhibit self-lubricating properties due to the facile sliding of graphene layers in the horizontal direction, facilitated by weak Van der Waals bonds along the c-axis. When this graphite material is impregnated with a lubricating liquid, it forms a solid and stable lubricating layer, and effectively reduces damage to the counter material from friction-induced wear under conditions of high-load reciprocating motion. This study investigates how oxidation-induced pore expansion and the silane treatment of graphite affect lubricating oil impregnation behavior, the friction coefficient of impregnated graphite, frictional stability, and microstructural changes at the friction surface. It was found that graphite oxidation within the chemical reaction temperature range enhanced porosity and increased the rate of lubricating oil impregnation. The functionalization of the graphite surface with hydrophobic silane coupling agents also significantly enhanced oil uptake, with a pronounced observed improvement when utilizing hydrophobic oils. Under a vertical load of 360 kgf and a surface pressure of 3 MPa, the graphite surface treated with hydrophobic silane and impregnated with oil exhibited the lowest average friction coefficient of 0.192 over 600 cycles. During the friction and wear process, a lubricating layer formed on the graphite surface, which contributes to stable wear performance. This surface modification strategy offers high applicability in industries such as automotive, aerospace, and heavy machinery, with the potential to significantly enhance component performance and extend service life under high-load, low-speed reciprocating conditions.
4,600원
25.
2025.12
구독 인증기관 무료, 개인회원 유료
Guoliang Chen, Dan Feng, Runqing Liu
This work introduces a high-performance absorber based on a lightweight composite material of corn straw biochar and magnetic cobalt nickel zinc ferrite. A composite absorber of corn straw biochar with hierarchical pore structure and magnetic zinc cobalt nickel ferrite particles (Ni–Co–Zn ferrite/C) was prepared by a simple two-step approach of carbonization followed by in-situ growth method. The morphology, structure, function, and absorbing properties of the prepared samples were characterized, and RCS simulation was performed. The results show that the optimal reflection loss value of Ni–Co–Zn ferrite/C-2 reaches −38.04 dB when the layer thickness is 3.5 mm, and the effective absorption bandwidth is 4.32 GHz. The potential of Ni–Co–Zn ferrite/C-2 composite material in stealth applications is verified. It is mainly attributed to the excellent impedance matching performance caused by the multi-level pore structure and the strong polarization loss caused by the rich heterogeneous interface and active sites, which plays a key role in the attenuation of electromagnetic waves. This study provides a useful reference for the design of magnetic ferrite particles/metal oxides/biomass-derived carbon microwave absorbing materials with hierarchical porous structure characteristics.
5,700원
26.
2025.12
구독 인증기관 무료, 개인회원 유료
Akhtar Iqbal, Yang Yang, Jianwei Dong, Amir Ali Khan, Yixuan Zhang, Yuanbo Bi, Zhen Luo
Carbon fibers (CFs) are notable for their lightweight, high strength, and excellent electrical conductivity, making them promising for applications like electrical wiring. However, integrating CFs into copper-based wiring systems faces challenges, particularly regarding conductivity loss in fractured CFs. This article discusses a two-step experiment to enhance electrical and mechanical connection. Electrothermal-induced solvent evaporation (EISE) and meniscus-confined electrochemical deposition (MECD) were identified as effective methods for welding fractured CFs and were successfully implemented in open-air environment. Deposition of carbon nanotubes (CNTs) around the fiber improved conductivity by reducing fiber-tofiber contact resistance and creating a metal-like surface. Microstructural analysis and EDS analysis revealed that the CNT cladding exhibited high density and fewer irregularities and bulges in the joint area. Furthermore, the CNTs were tangled, forming a less organized structure compared to the original CF. In contrast, the Cu cladding exhibited paint-like coverage, significant irregularities, bulges, and cracks but maintained a small thickness. Electrical testing revealed that the average resistance of a single joined fiber decreased to resistance of 11.45 Ω and an electrical resistivity of 2.27 Ω/m, demonstrating improved electrical conductivity. Under optimal conditions, the joined fibers exhibited plastic fracture, and all joints showed improved performance except joint 1.e-g enhanced mechanical strength and stress tolerance.
4,600원
27.
2025.12
구독 인증기관 무료, 개인회원 유료
Hua Liu, Chenxin Wang, Cheng Li, Xuan Yang, Cong Li, Zhi Song
The slow cathodic oxygen reduction rate (ORR) of microbial fuel cells (MFCs) is still one of the main bottlenecks in its industrialization. As an ORR catalyst, metal oxides are expected to significantly enhance ORR efficiency by providing active sites, regulating reaction pathways, and enhancing stability. In this paper, four bimetallic oxide catalysts, CuO/Co3O4, CuO/ MnO2, CuO/NiO, and CuO/Fe2O3, were synthesized by sol–gel method, and their structural characteristics were characterized. The results showed that CuO/Co3O4 exhibited the largest specific surface area and optimized pore structure, and the synergistic effect of Cu and Co significantly improved the electrochemical performance. As the cathode catalyst of MFCs, CuO/Co3O4 shows high ORR catalytic activity, low charge transfer resistance, and good stability. In MFCs application, CuO/ Co3O4 catalyst achieved the maximum power density of 227 mW m− 2. In the five-cycle test, the output voltage is stable at about 240 mV, and the COD removal rate reaches 91.9%, which shows great application potential in wastewater treatment.
4,500원
28.
2025.12
구독 인증기관 무료, 개인회원 유료
Chengqing Deng, Kai Pan, Xiaohui Zhang, Feiyan Lai, Guangchang Yang, Jiawen Guo
Bimetallic sulfides, as high-performance anode materials, exhibit high theoretical capacity. However, their practical application is hindered by inherent limitations, such as low electrical conductivity, sluggish charge transfer kinetics, and severe volume expansion. Interface-engineered heterostructures have emerged as a universal strategy to synergistically enhance conductive networks and suppress mechanical degradation. Carbon-based composites serve as optimal substrates due to their high conductivity and structural flexibility. In this study, we leverage the hierarchical porous architecture of expanded graphite (EG) to confine the self-assembly of Zn/Co precursors via a thiourea-assisted hydrothermal method, enabling in situ growth of Zn0.76Co0.24S nanoparticles within EG interlayers. Interfacial S–C covalent bonding, induced by π–π conjugation, establishes robust nanoscale coupling between Zn0.76Co0.24S and the carbon framework. The resulting “sandwich” heterostructure demonstrates exceptional cyclability (1086.9 mAh·g−1 after 500 cycles at 1.0 A·g−1) and rate capability (541.7 mAh·g−1 at 2.0 A·g−1). This work provides a generalizable design paradigm for high-performance multimetallic sulfide anodes through atomic-scale interface engineering.
4,200원
29.
2025.12
구독 인증기관 무료, 개인회원 유료
Maria Ulfa, Laurent Galmiche, Fabien Miomandre, Yahdi Bin Rus
This study explores the electrochemical modification of reduced graphene oxide (rGO) by incorporating 1,10-phenanthroline groups prior to the electrodeposition of silver nanoparticles (Ag NPs), aiming to enhance the performance on the oxygen reduction reaction (ORR). The introduction of 1,10-phenanthroline onto the rGO surface significantly improved its ability to coordinate metallic cations, compared to unmodified rGO. This enhanced coordination capacity led to a more efficient deposition of Ag NPs. Notably, increasing the amount of 1,10-phenanthroline groups grafted onto the rGO further boosted the number of deposited Ag NPs, substantially improving ORR performance. These results demonstrate that increasing the number of coordination units on rGO sheets prior to metal incorporation can significantly enhance the electrocatalytic efficiency of the resulting nanocomposites. This work emphasizes the importance of functionalizing rGO surfaces to optimize their catalytic properties for energy conversion and storage applications. This modification of rGO also paves the way for broader potential applications across various fields.
4,200원
30.
2025.12
구독 인증기관 무료, 개인회원 유료
Dongchen Zhao, Xiaofeng Yu, Zhongyuan Suo, Tingqu Li, Wencui Xiu, Baoming Yao, Zihao Chen, Jizhao Yu
In this study, GNPs/FeCoNiCuAl particles synergistically reinforced aluminum matrix composites are developed by friction stir processing (FSP) to explore the effects of different GNPs contents (1, 3, and 5%) on the microstructure, mechanical performance, and wear resistance of the materials. The results show that the incorporation of GNPs affects the formation of the diffusion layer between the FeCoNiCuAl particles and the aluminum matrix. As the content of GNPs increases, the thickness and integrity of the diffusion layer between FeCoNiCuAl particles and aluminum matrix gradually decrease. In addition, the introduction of GNPs is beneficial in enhancing the proportion of high-angle grain boundaries in the composites, but the grain size of the specimen increases slightly to about 5.5 μm at a content of 5% GNPs. When the content of GNPs is 1%, the composites achieve the highest microhardness and the lowest specific wear rate (0.1459 × 10⁻⁶ mm3/ N·m), with the wear mechanism dominated by abrasive wear. Nonetheless, when the GNPs content in the composite increases to 5%, the thickness and integrity of the diffusion layer are minimal, causing the tensile strength of the composite to be reduced to 250 MPa, and the specific wear rate increased to 0.4244 × 10– 6 ( mm3/N·m), with the wear mechanism transformed to abrasive–adhesive mixed wear. This study demonstrates that the appropriate ratio of GNPs and FeCoNiCuAl particles can effectively enhance the mechanical and wear resistance properties of aluminum matrix composites, providing a theoretical basis for the design and development of high-performance aluminum matrix composites.
5,100원
31.
2025.12
구독 인증기관 무료, 개인회원 유료
Kang Mi Lee, Jong Dae Lee
In this study, an anode composite material was fabricated by embedding spherical carbon-coated nanosilicon (Si@C) into a layered carbon-coated silicon (L-Si/C) to enhance the capacity and stability of silicon-based lithium-ion batteries. The L-Si/C material was obtained by reacting CaSi2 through a CO₂-assisted carbonization process, followed by removal of the CaCO3 byproduct via HCl etching. Si@C particles, prepared using polydopamine as a carbon precursor, were uniformly embedded in the L-Si/C via ultrasonic treatment. The physical properties of the prepared anode composites were analyzed using HR-SEM, EDS, XRD, and BET. The electrochemical performances were investigated using 1 M LiPF6 in EC:DEC (1:1 vol%) with 10 wt% FEC as the electrolyte, through charge–discharge cycling, rate capability tests, electrochemical impedance spectroscopy (EIS), and differential capacity (dQ/dV) analysis. L-Si/C exhibited the best electrochemical performance under the thermal treatment condition of 720 °C and a CO2 flow rate of 100 sccm. In addition, the application of ultrasonic treatment improved structural stability and rate capability. Consequently, the S_L-Si/C + Si@C-2 exhibited a high initial discharge capacity of 2700.7 mAh/g at 0.1 C and a capacity of 617.4 mAh/g at a high rate of 6 C.
4,000원
32.
2025.12
구독 인증기관 무료, 개인회원 유료
Haiyan Wang, Kun Duan, Jianglong Zhang, Siyi Pan
Carbon fiber reinforced polymer (CFRP)/titanium alloy (Ti) stacks have become a research focus in aerospace and advanced manufacturing due to their superior integrated properties. However, interfacial characteristics and interlayer gaps critically influence cutting forces and hole-making quality. So, a cutting simulation model for CFRP/Ti stacks with interlayer gaps is established, the cutting force variation with interlayer gaps during milling and the mechanistic role in interfacial defect formation are deciphered through multiscale simulations. In addition, the correctness of the simulated model is verified by helical milling experiments, and the influence of machined surface quality under different clearance conditions is also evaluated. The results reveal a four-stage nonlinear evolution pattern of interfacial cutting forces during helical milling of CFRP/Ti stacks with gaps. Further investigation indicates that this nonlinear evolution pattern results in the development of localized damage evolution regions adjacent to interlayer gaps in CFRP composites, especially. A characteristic stepped distribution pattern is observed in both hole-wall topography and burr dimensions within the affected zones.
4,600원
33.
2025.12
구독 인증기관 무료, 개인회원 유료
Irina A. Arefina, Evgeniia A. Stepanidenko, Sergey V. German, Margarita V. Nikiforova, Julijana Cvjetinovic, Kseniia A. Sergeeva, Elena I. Marusich, Alexey M. Yashchenok, Sergei A. Cherevkov, Elena V. Ushakova, Andrey L. Rogach
Multimodal composites have the potential to play a crucial role in the development of theranostic agents. Systems with optical and magnetic response can be applied in medicine for both imaging and therapy; however, combining magnetic and luminescent nanoparticles in one entity is challenging. Both the morphology and architecture of the composite, as well as the influence of the magnetic components and matrix on the light-emissive component, must be paid attention. In this study, we demonstrate a design of a composite with advantageous magnetic response and luminescence in green and red regions (excited at 405 and 580 nm, respectively), where biocompatible CaCO3 microspheres were loaded and decorated with luminescent carbon dots (CDs) and magnetite nanoparticles (MNPs). We showed the absence of CDs’ toxicity by the IC50 tests and demonstrated its localization in L1 and L4 stages of C. elegans embryogenesis. We determine the optimal parameters for composite formation to achieve their improved performance and structural stability. The composites were fabricated in several steps, including loading nanoparticles and layer-by-layer application of polyelectrolytes on top of CaCO3. We demonstrated the applicability of the prepared composite microspheres for flow cytometry and showed their potential as multiplexed visualization agents, emphasizing their potential use as promising theranostic agents.
4,200원
34.
2025.12
구독 인증기관 무료, 개인회원 유료
Kitak Kim, Jongyeop Choi, Seunghoon Nam
Sodium-ion batteries (SIBs) have emerged as a promising alternative to lithium-ion batteries due to the natural abundance and low cost of sodium resources. However, the relatively large ionic radius of sodium ions hinders their intercalation into conventional graphite anodes, necessitating the development of advanced anode materials. In this study, high-performance hard carbon materials were synthesized from ZIF-8 precursors through controlled carbonization at various temperatures. Among the samples, ZIF-800, which is carbonized at 800 °C, exhibited the highest reversible capacity (156.63 mAh/g after 100 cycles at 100 mA/g) and excellent cycling stability. This superior performance is attributed to the optimized combination of high specific surface area (700.35 m2/ g), well-developed pore structure, and enhanced defect concentration, as indicated by a low IG/ ID ratio. The capacitive-dominant charge storage behavior further contributes to the improved electrochemical characteristics. These findings highlight the critical role of tuning carbonization temperature to achieve a balanced microstructure, offering valuable insights for the rational design of high-performance hard carbon anodes for SIBs.
4,000원
35.
2025.12
구독 인증기관 무료, 개인회원 유료
Shiquan He, Louwei Cui, Jiaojiao Liu, Sijie Wang, Yanyan Song, Ting He, Tao Liu, Huaan Zheng, Yonghong Zhu, Dong Li
Medium- and low-temperature coal tar pitch can be prepared as coal-based mesophase pitch for its high value-added utilization. However, its lower aromaticity and higher content of heteroatoms (especially O atoms) led to a higher content of the resulting mesophase pitch mosaic structure. In this study, mesophase pitch was prepared by co-carbonization of high aromaticity, low oxygen content high-temperature refined pitch (RHCTP) with medium- and low-temperature coal tar refined pitch (RCTP). The impact of various blending ratios on the optical and microcrystalline structures of mesophase pitch was analyzed using polarized light microscopy, X-ray diffraction, and Raman spectroscopy. The addition of RHCTP to modify RCTP significantly enhanced the optical and microcrystalline structures of the co-carbonized products. The optimal blending ratio (R-25%) was obtained. Needle coke prepared from mesophase pitch obtained from R-25% had superior fine fiber structure, lowest average resistivity (157.37 μΩ·m) and high true density (2.125 g/cm3). The thermal conversion behavior of the blended refined pitch during co-carbonation was analyzed using thermogravimetric data of the R-25% sample through four isoconversion methods. The thermal conversion of the R-25% sample occurs in three stages: the first stage follows the Parabola law model, while the second and third stages adhere to the random nucleation and nuclei growth model. This analysis of thermal conversion kinetics offers theoretical insights for optimizing mesophase pitch preparation process conditions and reactor design.
5,400원
36.
2025.12
구독 인증기관 무료, 개인회원 유료
Syun Gohda, Kana Fujioka
The co-sintered phosphor of cerium-doped yttrium aluminum garnet (YAG:Ce) and aluminum nitride (AlN) is a promising material for next-generation light-emitting diode lighting applications. Despite AlN’s excellent thermal conductivity, its high sintering temperature and surface reactivity limit its industrial use in co-sintered phosphors, and effective methods to improve its sinterability without compromising properties remain underexplored. In this study, the sinterability of the AlN and YAG:Ce composite is improved by coating AlN particles with a soluble carbon material (SCM) prior to sintering. SCM coating leads to a 6.75% increase in photoluminescence (PL) intensity under 15 W laser excitation and a 6.85% improvement in thermal conductivity, which suppresses thermal quenching. The enhanced thermal conductivity also minimizes PL decay over time, thereby maintaining high luminosity for extended periods. Furthermore, the hardness and handling properties of the obtained sintered body are significantly improved, with hardness increasing by 112.3% when SCM-coated AlN is used. Notably, the SCM does not remain in the final product, as it is fully removed during sintering, leaving no impurities or adverse effect on the material’s properties. Given its ability to easily and uniformly coat ceramic particles, SCM coating holds promise for broader application in enhancing the sinterability and performance of various ceramic-based materials.
4,000원
37.
2025.12
구독 인증기관 무료, 개인회원 유료
Zhenyu Wu, Yuhang Zhang, Lin Shi, Zhi Yang, Xiaoying Cheng, Hongjun Li, Duncan Camilleri
This study investigates the repeated impact behavior and compression-after-impact (CAI) performance of triaxially braided carbon/glass fiber-reinforced polymer (C/GFRP) composite tubes. A two-stage experimental strategy was proposed to evaluate the synergistic effect of interlayer hybridization and axial yarn reinforcement on damage evolution and mechanical performance. In Stage I, six hybrid braided tubes with different carbon/glass stacking configurations—including pure carbon, pure glass, layered, and reversed-layered structures—were subjected to repeated low-velocity impacts at 31 J. Micro-CT was employed to reconstruct the internal damage morphology and assess damage accumulation. The optimal interlayer configuration was selected based on impact force, displacement, energy absorption, and internal failure characteristics. In Stage II, the selected structure was further reinforced with four types of axial yarns (none, carbon, glass, and carbon/glass alternating), and their axial compressive and CAI performance after 10 J impact was tested. Results revealed that reversed interlayer design effectively suppressed crack propagation and improved damage tolerance under cyclic impacts. Moreover, the inclusion of hybrid axial yarns significantly enhanced residual compressive strength without compromising energy absorption. This study establishes a lightweight, high-performance braided tube design strategy suitable for aerospace and transportation applications.
5,700원
38.
2025.12
구독 인증기관 무료, 개인회원 유료
To enhance the fixed carbon content and recovery rate of flotation concentrates from low-grade natural flake graphite (NFG), this study employed synchronous ultrasonic flotation in combination with inorganic salt ion (NaCl) enhancement. Flotation experiments were conducted to investigate the synergistic effects of these two methods. X-ray photoelectron spectroscopy, contact angle analysis, laser particle-size analysis, Raman spectroscopy, infrared spectroscopy, zeta potential measurements, electron microscopy, and Debye length calculations confirmed that ultrasonic cavitation disrupted particle agglomeration and cleaned the graphite surface. This process generated fine micro-/nanobubbles with enhanced hydrophobicity, significantly improving concentrate recovery rates. NaCl addition compressed the double electric layer on particle surfaces and suppressed bubble coalescence, stabilizing the froth and promoting graphite–bubble adhesion, which markedly increased the fixed carbon content of the concentrate. The results demonstrated that through the integrated approach, low-grade NFG with an initial fixed carbon content of 7.98% was upgraded after rough processing to a concentrate containing 79.24% fixed carbon, with a recovery rate of 65.76%. These findings demonstrate that combining ultrasonic flotation with NaCl addition substantially improved both fixed carbon content and recovery rate in the concentrate. Overall, this study provides a novel technical pathway for the efficient utilization of low-grade graphite ore resources.
5,800원
39.
2025.12
구독 인증기관 무료, 개인회원 유료
Taeyoung Park, Jang Hee Kim, Hyeon Ji Jeong, Kwang Hyun Park, Jungmo Kim, Sung Ho Song, Wang‑Geun Shim
Activated carbons with high micro-/meso-porosity derived from biomass are increasingly popular as sustainable materials. However, these carbons often struggle with low carbon content and limited structural stability. Here, we present Mongolian anthracite-based carbons synthesized via carbonization and chemical activation. Structural analysis shows that Act-MRA samples develop plate-like morphologies with reduced particle size and greater porosity as KOH content increases. The Act-MRA samples have a disordered carbon structure with small graphitic domains, even at higher KOH ratios without significant crystal defects. Notably, Act -MRA3 displays a large specific surface area and high pore volume, with welldeveloped micropores (7–20 Å) and mesopores (20–50 Å) that expand as KOH ratios rise. Electrochemical tests indicate that Act -MRA3 achieves high specific capacitance (220.6 F/g at 5 mV/s) and rate retention (~ 80% at 300 mV/s), owing to its optimized pore structure and enhanced ion transport. These findings underscore the importance of tailored pore structures and defect engineering in boosting activated carbon performance for energy storage.
4,000원
40.
2025.12
구독 인증기관 무료, 개인회원 유료
Ghidaa Badran, Tengfei Wang, Yunseok Shin, Sungjin Park, Alberto Bianco
Carbon nitride ( C3N4) is a class of nanomaterials that recently became increasingly important in the field of health and biomedicine. However, there is a lack of data regarding its toxicity and how this type of material affects the cells of the innate immune system, such as macrophages. The objective of this study was to evaluate and compare the effect of C3N4 in its pristine and oxidized ( oxC3N4) forms using a monocytic cell line differentiated into macrophages. Human THP-1 cells, differentiated into macrophages, were exposed to increasing concentrations of C3N4 and oxC3N4 (e.g., 10, 50 and 100 μg/mL). The assessment of the overall cytotoxicity, by quantifying intracellular adenosine triphosphate (ATP), apoptosis, change of mitochondrial membrane potential and generation of reactive oxygen species (ROS), was carried out. The results showed a significant decrease in cellular ATP after 48 and 72 h of exposure to both type of nanomaterials. The subsequent staining with annexin V and propidium iodide confirmed a significant increase in cell death induced by oxC3N4, but not by pristine C3N4. A significant decrease in mitochondrial membrane potential was also observed only when macrophages were exposed to C3N4, raising question about the presence of a cell death mechanism not involving mitochondria and masking apoptosis in the case of the oxidized carbon nitride. In addition, in the non-cytotoxic condition, oxC3N4 was able to induce ROS generation. Taken together, our results show that the oxidized form of C3N4 is that affecting more the viability of macrophages.
4,000원
