Carbon Trends最新文献

Natural Kapok fiber-derived two-dimensional carbonized sheets as sustainable electrode material 作为可持续电极材料的天然木棉纤维二维碳化片

IF 3.1 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Carbon Trends

Pub Date : 2024-10-28 DOI: 10.1016/j.cartre.2024.100418

Natural biomass-derived carbon nanostructures have attracted research interest because of their unique surface and electrochemical properties. The present study embodied the carbonized micro-nano sheets derived from the low-cost natural source Kapok silk fiber. The material was obtained via a facile thermal pyrolysis process. Diffraction analysis showed a broad graphene structure-like peak, indicating the formation of graphene-like carbon nanosheets. Field emission scanning electron microscope (FESEM) and transmission electron microscopic (TEM) images confirmed the presence of fragmented carbon sheets, some of which were folded to form a tube-like structure. Raman study showed the presence of D and G band with the Id/Ig ratio of 0.96 which indicated the formation of few-layered carbon nanosheets. Furthermore, the electrochemical performance was evaluated for lithium-ion battery as well as supercapacitor. A specific capacity of 465 mAh.g^-1 at 0.1 C rate for Li-ion battery and a specific capacitance of 473.61 F.g^-1 for supercapacitor have been obtained with the capacitance retention of 95 %. This study provides insights into a strategy for the sustainable production and utilization of natural fiber-based carbon in energy storage systems.

源自天然生物质的碳纳米结构因其独特的表面和电化学特性而备受研究关注。本研究体现了从低成本天然来源木棉蚕丝纤维中提取的碳化微纳米片。该材料通过简便的热解工艺获得。衍射分析显示了一个宽广的类似石墨烯结构的峰值，表明形成了类似石墨烯的碳纳米片。场发射扫描电子显微镜（FESEM）和透射电子显微镜（TEM）图像证实了碎碳片的存在，其中一些被折叠形成管状结构。拉曼研究显示存在 D 和 G 波段，Id/Ig 比为 0.96，这表明形成了少层碳纳米片。此外，还对锂离子电池和超级电容器的电化学性能进行了评估。在 0.1 C 速率下，锂离子电池的比容量为 465 mAh.g-1，超级电容器的比电容为 473.61 F.g-1，电容保持率为 95%。这项研究为储能系统中天然纤维基碳的可持续生产和利用战略提供了启示。

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引用次数: 0

Localized surface plasmon resonance induced nonlinear absorption and optical limiting activity of gold decorated graphene/MoS2 hybrid 金装饰石墨烯/MoS2 杂化物的局部表面等离子体共振诱导非线性吸收和光学极限活性

IF 3.1 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Carbon Trends

Pub Date : 2024-10-21 DOI: 10.1016/j.cartre.2024.100417

The synergistic supremacy of a hybrid nanocomposite made of reduced graphene oxide (rGO), molybdenum disulfide (MoS₂) and gold nanoparticles (Au) for Q-switching and optical limiting applications is investigated. Hydrothermally synthesized Au-rGO-MoS₂ hybrid with varying concentrations of Au (2.5, 5, 7.5 and 10 wt%) was subjected to interact with Q-switched Nd:YAG nanosecond green laser pulses. The intensity dependent nonlinear absorption studies revealed a switch over in the nonlinear behaviour from saturable absorption (SA) to reverse saturable absorption (RSA) behaviour. SA occurs due to ground state bleaching at comparatively lower laser irradiances serving the need for Q-switching and optical communications. The RSA trait at higher laser irradiance is attributed to sequential two-photon absorption which serves as the platform for optical limiting behaviour prompting laser safety and effective photothermal therapy applications. The strong mid-visible and UV absorption promotes the availability of multiple energy bands for energy transitions of excited state absorption (ESA). Enhanced local fields due to localized surface plasmon resonance effect, structural defects, hierarchical morphology, increased absorption cross-section and plasmon induced energy transfer promotes robust ESA process. These tunable nonlinear optical properties make Au-rGO-MoS₂ hybrid promising futuristic candidates for applications in nonlinear photonic devices, ultrafast optical switches and all-optical signal processing systems.

本研究探讨了还原氧化石墨烯（rGO）、二硫化钼（MoS2）和金纳米粒子（Au）混合纳米复合材料在 Q 开关和光学限制应用中的协同优势。水热合成的 Au-rGO-MoS2 杂化物含有不同浓度的 Au（2.5、5、7.5 和 10 wt%），与 Q 开关 Nd:YAG 纳秒绿色激光脉冲相互作用。与强度相关的非线性吸收研究表明，非线性行为从可饱和吸收（SA）转换为反向可饱和吸收（RSA）行为。在相对较低的激光辐照度下，由于基态漂白，会产生可饱和吸收，从而满足 Q 开关和光通信的需要。较高激光辐照度下的 RSA 特性则归因于连续的双光子吸收，它是光限制行为的平台，可促进激光安全和有效的光热治疗应用。强烈的中可见光和紫外线吸收促进了激发态吸收（ESA）能量转换的多能带可用性。由于局部表面等离子体共振效应、结构缺陷、分层形貌、吸收截面增大以及等离子体诱导的能量转移，增强了局部场，从而促进了稳健的 ESA 过程。这些可调谐的非线性光学特性使得 Au-rGO-MoS2 混合材料在非线性光子器件、超快光开关和全光信号处理系统中的应用前景广阔。

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引用次数: 0

Enhanced storage performance of a low-cost hard carbon derived from biomass 提高从生物质中提取的低成本硬碳的储存性能

IF 3.1 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Carbon Trends

Pub Date : 2024-10-19 DOI: 10.1016/j.cartre.2024.100415

Hard Carbon is the most widely used negative electrode material for sodium-ion batteries today. Achieving high storage capacity and increasing the plateau capacity, as opposed to the sloping profile, are crucial for enhancing energy density of the full cells. While several publications address the synthesis of hard carbon, the economic viability for commercial scale-up hinges on the choice of precursors. In this study, we report the electrochemical properties of hard carbon derived from two biomass precursors, sugarcane waste (bagasse) and corn waste, and compare their performances with commercially available hard carbon. The hard carbon derived from bagasse delivers a capacity of 307 mAh/g at C/10 rate and retains approximately 234 mAh/g at 3C discharge rate. We integrate surface area, pore size distribution, Raman spectroscopy, small-angle X-ray and neutron scattering data to elucidate the sodium storage mechanism in these hard carbon samples. Correlated graphitic domains with hexagonal ordering along with fractal like agglomeration of the nanosheets are quantified. The high plateau capacity of the bagasse-derived hard carbon is attributed to the characteristic morphology and size distribution of the nanosheets and their nature of agglomeration.

硬碳是目前钠离子电池最广泛使用的负极材料。实现高存储容量和提高高原容量（而不是斜坡容量）对于提高全电池的能量密度至关重要。虽然有多篇论文论述了硬碳的合成，但商业放大的经济可行性取决于前驱体的选择。在本研究中，我们报告了从甘蔗渣和玉米渣这两种生物质前驱体中提取的硬质碳的电化学特性，并将它们的性能与市售硬质碳进行了比较。从甘蔗渣中提取的硬质碳在 C/10 放电速率下的容量为 307 mAh/g，在 3C 放电速率下的容量约为 234 mAh/g。我们整合了表面积、孔径分布、拉曼光谱、小角 X 射线和中子散射数据，以阐明这些硬碳样品中的钠存储机制。我们对具有六方有序性的相关石墨畴以及纳米片的分形聚集进行了量化。甘蔗渣衍生硬碳的高原容量归因于纳米片的特征形态和尺寸分布及其聚结性质。

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引用次数: 0

Nanoscale friction and wear of graphite surface in ambient and underwater conditions 石墨表面在环境和水下条件下的纳米级摩擦和磨损

IF 3.1 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Carbon Trends

Pub Date : 2024-10-13 DOI: 10.1016/j.cartre.2024.100414

The tribological properties of graphite are extremely sensitive to surrounding environment, which affects its longevity and friction reduction performance. This study aims to develop a comprehensive understanding of the effects of a liquid environment on interactions at the sliding interface, thereby influencing the nanoscale tribological properties of graphite surfaces. By combining atomic force microscopy experiments and molecular dynamics simulations, we conducted a comparative analysis of friction and wear behavior of graphite under two different environmental conditions: ambient (air) and underwater condition. Our investigations explored both the step edge and interior (step-free) graphite surfaces. The experimental results revealed a notable contrast in the frictional and wear behavior of graphite at nanoscale in these two environments. The interior surface exhibited a friction coefficient (COF) of approximately 0.003 and 0.006 against a diamond-coated surface in ambient and underwater conditions, respectively. Interestingly, the underwater environment not only increased friction but also significantly compromised the wear resistance of graphene layers near the graphite surface compared to the ambient environment, as evidenced in both step edge and interior step-free regions. The interior region sustained up to ∼7400 nN load in ambient condition but failed at ∼1500 nN under water. Similarly, the step edge failed at ∼375 and ∼187.5 nN in ambient and underwater conditions, respectively. Our simulations revealed that the increased friction in underwater condition is due to resistance of surrounding water molecules during tip sliding. The presence of water at tip-graphite contact interface generated substantial localized stress, leading to the initiation of wear and revealing the pronounced effect of water on the wear characteristics of graphite in underwater condition.

石墨的摩擦学特性对周围环境极为敏感，这会影响其使用寿命和减摩性能。本研究旨在全面了解液体环境对滑动界面相互作用的影响，从而影响石墨表面的纳米级摩擦学特性。我们结合原子力显微镜实验和分子动力学模拟，对石墨在环境（空气）和水下两种不同环境条件下的摩擦和磨损行为进行了比较分析。我们的研究同时探索了石墨的阶梯边缘和内部（无阶梯）表面。实验结果表明，在这两种环境下，纳米级石墨的摩擦和磨损行为形成了明显的对比。在环境和水下条件下，内表面与金刚石涂层表面的摩擦系数（COF）分别约为 0.003 和 0.006。有趣的是，与周围环境相比，水下环境不仅增加了摩擦力，还大大降低了石墨表面附近石墨烯层的耐磨性，这一点在阶梯边缘和内部无阶梯区域都有体现。内部区域在环境条件下可承受高达 ∼7400 nN 的载荷，但在水下则在∼1500 nN 时失效。同样，在环境和水下条件下，阶梯边缘分别在 375 和 187.5 nN 下失效。我们的模拟结果表明，水下条件下摩擦力增大的原因是尖端滑动时周围水分子的阻力。水在尖端与石墨的接触界面上产生了巨大的局部应力，导致了磨损的开始，并揭示了水在水下条件下对石墨磨损特性的明显影响。

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引用次数: 0

Structural, electronic and dielectric properties of carbon nanotubes interacting with Co nanoclusters 与 Co 纳米团簇相互作用的碳纳米管的结构、电子和介电特性

IF 3.1 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Carbon Trends

Pub Date : 2024-10-11 DOI: 10.1016/j.cartre.2024.100410

A new frontier in tuning the electromagnetic response of carbon-based materials, particularly carbon nanotubes, consists in adding metallic clusters or nanoparticles at their external surface. This allows to change optical, dielectric and magnetic properties with potential applications in electronics and telecommunications for aeronautics. By resorting to first principles dynamical simulations, we provide a microscopic picture of the interaction at finite temperature between a carbon nanotube and Co aggregates mimicking the experimental coverage. The electronic structure evolution provides the absorption spectrum and the dielectric function for comparison with experiments and guidelines for tuning these composite systems.

调整碳基材料（尤其是碳纳米管）电磁响应的一个新领域是在其外表面添加金属团簇或纳米粒子。这可以改变其光学、介电和磁学特性，并有望应用于航空电子和电信领域。通过第一原理动力学模拟，我们提供了碳纳米管与钴聚集体在有限温度下相互作用的微观图景，模拟了实验覆盖范围。电子结构演化提供了吸收光谱和介电函数，以便与实验进行比较，并为调整这些复合系统提供指导。

引用次数: 0

The influence of carbon content to the band gap of ABC stacked trilayer hybridized graphene and hexagonal boron nitride 碳含量对 ABC 叠层三层杂化石墨烯和六方氮化硼带隙的影响

IF 3.1 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Carbon Trends

Pub Date : 2024-10-10 DOI: 10.1016/j.cartre.2024.100413

The influence of carbon content on the band gap of ABC stacked trilayer hybridized graphene and hexagonal boron nitride (h-BNC) are calculated by first-principles calculations. The formation energy results indicate that the configurations with cluster of boron(B) and nitrogen(N) atoms are more stable than that with separate. By calculating the band structures of seven doping models, we found that the band gap reduces with the ascendance of carbon atom concentration. With the increase of the carbon atom content, the optical absorption peak shifts to longer wavelength range. Combined with the band structure results, the red-shift is due to the reduction of the bandgap with the increase of the carbon atom content. The density of states, charge densities and Mulliken populations suggest that the collapse of the band gap is attributed to the charge transfer between atoms in the seven doping models of the h-BNC system. This work is valuable for the band structure engineering of h-BNC.

通过第一性原理计算了碳含量对 ABC 叠层三层杂化石墨烯和六方氮化硼（h-BNC）带隙的影响。形成能结果表明，硼原子（B）和氮原子（N）组成的构型比单独组成的构型更稳定。通过计算七种掺杂模型的能带结构，我们发现能带间隙随着碳原子浓度的增加而减小。随着碳原子含量的增加，光吸收峰向更长的波长范围移动。结合带状结构结果，红移是由于带隙随着碳原子含量的增加而减小。状态密度、电荷密度和 Mulliken 种群表明，带隙的塌缩归因于 h-BNC 系统七个掺杂模型中原子间的电荷转移。这项工作对 h-BNC 的带状结构工程很有价值。

引用次数: 0

Optical investigation of degradation of graphene oxide in alkaline environment: Evidence of two distinct photon-emitting phases in visible region. 碱性环境中氧化石墨烯降解的光学研究：可见光区域两种不同光子发射阶段的证据。

IF 3.1 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Carbon Trends

Pub Date : 2024-10-09 DOI: 10.1016/j.cartre.2024.100412

In this work we show a procedure of treating of the graphene oxide in alkaline environment as a function of the treatment time in order to obtain novel structures with strong luminescence properties, water-stable, useful as potential replacement for critical raw materials employed as example in optical and optoelectronic devices or for diagnostic and therapeutic technology. These structures have distinct blue and green-luminescence properties which derived most likely from different structural conformations, one associable with that of carbon quantum dots (or as an alternative to that of the Oxidative Debris), the other, lighter and more similar to organic compounds, reported in literature as fulvic-like molecules, but whose nature has to be further investigated. We show that the lighter fraction has a dual mechanism of photoemission: the excitation-independent PL for excitation wavelength within 350 nm and the excitation-dependent component for excitation wavelength ranging in the visible spectrum. The PL dual behaviour could depend on fluorescent nanoclusters composed by specific organic fluorophores with a carbonaceous core. FTIR analysis shows reasonably the same functional groups unless of some difference discussed in the text, meanwhile UV–Vis and PL analysis clearly highlight two distinct emissions (450 nm and 530 nm) in the visible region of the electromagnetic spectrum. Excitation-dependent photoluminescence, water stability and organic fluorescent nanostructures are issues particularly required for application in the biological field but also in materials science.

在这项工作中，我们展示了一种在碱性环境中处理氧化石墨烯的方法，该方法是处理时间的函数，目的是获得具有强发光特性的新型结构，这种结构在水中稳定，有可能替代光学和光电设备或诊断和治疗技术中使用的关键原材料。这些结构具有不同的蓝色和绿色发光特性，很可能来自不同的结构构象，其中一种与碳量子点的结构构象有关（或可替代氧化碎片的结构构象），另一种较轻，更类似于有机化合物，文献报道为富勒烯类分子，但其性质还有待进一步研究。我们的研究表明，较轻的部分具有双重光发射机制：在激发波长为 350 纳米以内时，具有与激发无关的光致发光特性；在可见光谱范围内，具有与激发有关的光致发光特性。光致发光的双重特性可能取决于由特定有机荧光团和碳质核心组成的荧光纳米团簇。傅立叶变换红外光谱分析显示出相同的官能团，但文中讨论的某些差异除外，而紫外可见光和聚光分析则清楚地显示出电磁波谱可见光区的两种不同发射（450 nm 和 530 nm）。与激发有关的光致发光、水稳定性和有机荧光纳米结构是生物领域和材料科学应用中特别需要解决的问题。

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引用次数: 0

Supramolecular interactions in graphene–chitosan composites with plasmonic nanoparticles 带有等离子纳米粒子的石墨烯-壳聚糖复合材料中的超分子相互作用

IF 3.1 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Carbon Trends

Pub Date : 2024-10-08 DOI: 10.1016/j.cartre.2024.100405

The supramolecular interactions between graphene and biopolymers, such as chitosan, determine both whether nanostructured-hybrid materials are formed and their technologically relevant physical/chemical properties. However, there is still a fundamental lack of knowledge about how nanocomposites based on chitosan and graphene are formed, as well as their intrinsic structure and interaction with plasmonic nanoparticles. In this work, we provide an in-depth understanding of the supramolecular interactions between chitosan and graphene in the formation of graphene–chitosan nanocomposites with gold or silver nanoparticles. To do so, we employ a combination of Raman spectroscopy, Fourier-transformed infrared (FTIR) spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) measurements with density functional theory (DFT) calculations to reveal the mechanism and driving forces behind these supramolecular interactions between graphene and chitosan. Specifically, we show they are based on a charge transfer process derived from the protonation of the amine groups of chitosan in acidic media. The understanding of the supramolecular interaction between graphene and chitosan that we provide herein should prove of great importance and interest to the material sciences and biomedical engineering fields.

石墨烯与壳聚糖等生物聚合物之间的超分子相互作用决定了是否会形成纳米结构杂化材料及其技术上相关的物理/化学特性。然而，人们对基于壳聚糖和石墨烯的纳米复合材料是如何形成的，以及它们的内在结构和与等离子纳米粒子的相互作用仍然缺乏基本的了解。在这项工作中，我们深入了解了壳聚糖和石墨烯在与金或银纳米粒子形成石墨烯-壳聚糖纳米复合材料过程中的超分子相互作用。为此，我们将拉曼光谱、傅立叶变换红外光谱、原子力显微镜、扫描电子显微镜、X 射线光电子能谱测量与密度泛函理论计算相结合，揭示了石墨烯与壳聚糖之间超分子相互作用的机理和驱动力。具体来说，我们发现它们是基于壳聚糖胺基在酸性介质中质子化所产生的电荷转移过程。我们在此提供的对石墨烯与壳聚糖之间超分子相互作用的理解，应能证明对材料科学和生物医学工程领域具有重大意义和兴趣。

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引用次数: 0

Observation of novel carbon nanocorals during the synthesis of graphene and investigations on their composition, morphological and structural properties 在合成石墨烯过程中观察新型碳纳米珊瑚并研究其组成、形态和结构特性

IF 3.1 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Carbon Trends

Pub Date : 2024-10-06 DOI: 10.1016/j.cartre.2024.100411

Novel carbon nanocorals (CNCs) are observed during the synthesis of graphene on copper substrates by thermal chemical vapor deposition, using precursor gas acetylene (C₂H₂) and carrier gas argon (Ar). CNCs have unique structure and investigations are carried out on structural and elemental compositions by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray excited Auger electron spectroscopy (XAES), energy dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), and high resolution transmission electron microscopy (HRTEM). The graphitic nature of the CNCs is evident from characteristic D, G, and 2D bands obtained from Raman spectrum. Elemental composition analysis by XPS shows presence of sp² and sp³ hybridized carbon whereas XAES quantifies percentage of sp² and sp³ hybridized carbon. FESEM micrographs show a uniform distribution of densely packed CNCs throughout the sample, and formation of groups of CNCs with distinct contours on the surface. The cross-sectional FESEM shows stacking of large number of graphene layers with dendrites. HRTEM analysis further supports observations of FESEM and elaborates structural morphology of the CNCs. Synthesis, characterization and analysis of the properties of carbon nanocorals are reported here, for the first time.

使用前驱气体乙炔（C2H2）和载气氩气（Ar），通过热化学气相沉积法在铜基底上合成石墨烯时，观察到了新型碳纳米珊瑚（CNCs）。CNC 具有独特的结构，研究人员通过 X 射线衍射 (XRD)、拉曼光谱、X 射线光电子能谱 (XPS)、X 射线激发欧杰电子能谱 (XAES)、能量色散 X 射线能谱 (EDS)、场发射扫描电子显微镜 (FESEM) 和高分辨率透射电子显微镜 (HRTEM) 对其结构和元素组成进行了研究。从拉曼光谱中获得的 D、G 和 2D 带特征可以看出 CNC 的石墨性质。XPS 元素组成分析表明存在 sp2 和 sp3 杂化碳，而 XAES 则量化了 sp2 和 sp3 杂化碳的百分比。FESEM 显微照片显示整个样品均匀分布着密集的 CNC，并在表面形成具有明显轮廓的 CNC 群。横截面的 FESEM 显示了大量石墨烯层与树枝状石墨烯层的堆叠。HRTEM 分析进一步支持了 FESEM 的观察结果，并详细说明了 CNC 的结构形态。本文首次报道了碳纳米陶瓷的合成、表征和性质分析。

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引用次数: 0

Recent research trends in the rational design strategies of carbon-based electrocatalysts for electrochemical ammonia synthesis 用于电化学氨合成的碳基电催化剂合理设计策略的最新研究趋势

IF 3.1 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Carbon Trends

Pub Date : 2024-10-05 DOI: 10.1016/j.cartre.2024.100409

Ammonia electrosynthesis is the most sustainable way to produce carbon-free hydrogen carriers, which would pave the way for the foreseen hydrogen economy and carbon neutralization as it has the potential to replace the conventional Haber-Bosch process. The electrocatalytic production of ammonia, which renewable energy resources could drive, reduces the carbon footprint contribution to fossil fuel consumption. Moreover, ammonia electrosynthesis also paves the way for recycling industrial/chemical wastewater and NO emissions. Hence, the advancement of electrocatalytic ammonia synthesis techniques is highly mandated for a greener future. This review consolidates the recent research trends associated with carbon-based electrocatalysts, which could elevate this viable technology with cost-effectiveness.

氨电合成是生产无碳氢载体的最可持续的方法，这将为预期的氢经济和碳中和铺平道路，因为它有可能取代传统的哈伯-博施工艺。氨的电催化生产可以利用可再生能源，减少化石燃料消耗的碳足迹。此外，氨的电合成还为回收工业/化学废水和 NO 排放物铺平了道路。因此，为了实现更加绿色的未来，必须大力发展电催化氨合成技术。本文综述了与碳基电催化剂相关的最新研究趋势，这些研究可提高这项技术的可行性和成本效益。

引用次数: 0