IF 10.5 2区材料科学

Carbon Pub Date : 2024-11-02 DOI: 10.1016/j.carbon.2024.119796

Leslie R. Sigmon , Jonathan Catazaro , Mohammed Abdel-Rahman , Casey Smith , Carsten Prasse , D. Howard Fairbrother

{"title":"Interrogating the photoluminescent properties of carbon dots using quantitative 13C NMR combined with systematic photobleaching","authors":"Leslie R. Sigmon , Jonathan Catazaro , Mohammed Abdel-Rahman , Casey Smith , Carsten Prasse , D. Howard Fairbrother","doi":"10.1016/j.carbon.2024.119796","DOIUrl":"10.1016/j.carbon.2024.119796","url":null,"abstract":"<div><div>In this work, molecular-level events accompanying the photobleaching of carbon dots (CDs) synthesized from ethylenediamine and citric acid (CACDs) were identified using solution-phase NMR. By combining quantitative <sup>13</sup>C NMR data with fluorescence measurements we show that this new approach is capable of identifying not only molecular fluorophores in CACDs, but also their contribution to the overall CACD fluorescence and their relative photostability. Specifically, imidazo[1,2-a]pyridine-7-carboxylic acid (IPCA) is found to be the dominant (84 %) species responsible for fluorescence in CACDs along with a second undetermined source, most likely associated with the aromatic core which is significantly (approximately 20 times) more photostable than IPCA. The presence of these two fluorescent species with different photostabilities rationalizes not only the photobleaching kinetics but also the evolution of the fluorescence spectrum during photobleaching Diffusion-ordered spectroscopy (DOSY) also reveals that all of the IPCA molecules are trapped within or covalently bound to the CACD, but are not present as isolated molecules freely rotating in solution. Singlet oxygen is confirmed as a key ROS responsible for photobleaching, with prototypical photoproducts identified from mass spectrometry studies of citrazinic acid. Quantitative <sup>13</sup>C NMR of CACDs is possible because their extremely high colloidal stability enables high concentrations (667 mg/mL) to remain stable in solution. The approach described in this study could be extended to identify the structure of chromophores in other CDs and interrogate molecular level processes that accompany CD sensing.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":null,"pages":null},"PeriodicalIF":10.5,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multifunctional chitosan-derived MnO@C aerogels with high radar-infrared compatible stealth 具有高雷达-红外兼容隐身性能的多功能壳聚糖衍生 MnO@C 气凝胶

IF 10.5 2区材料科学

Carbon Pub Date : 2024-11-01 DOI: 10.1016/j.carbon.2024.119789

Shi Jin , Haixia Huang , Xianlong Zhang , Xueping Wu , Kui Wang

{"title":"Multifunctional chitosan-derived MnO@C aerogels with high radar-infrared compatible stealth","authors":"Shi Jin , Haixia Huang , Xianlong Zhang , Xueping Wu , Kui Wang","doi":"10.1016/j.carbon.2024.119789","DOIUrl":"10.1016/j.carbon.2024.119789","url":null,"abstract":"<div><div>The increasing demand for advanced detection technologies has highlighted the need for materials with efficient electromagnetic wave absorption (EMWA) and thermal stealth, crucial for radar-infrared compatibility. In this study, we synthesized honeycomb-like porous MnO@C aerogels via the sol-gel method, achieving remarkable multifunctional properties. The MnO@C-10 wt% (10 wt% Mn) exhibited a minimum reflection loss (RL<sub>min</sub>) of −54.08 dB at an optimum thickness of 3.2 mm and a maximum effective absorption bandwidth (EAB) of 5.96 GHz at 2.6 mm. Additionally, it demonstrated a significant reduction in radar scattering cross section (RCS) of 27.2 dB m<sup>2</sup> at 0<sup>o</sup> detection angle. The material's infrared stealth was confirmed by its ability to maintain a surface color consistent with its surroundings and a surface temperature of approximately 30 °C after heating at 90 °C for 1 h, highlighting its superior infrared stealth and thermal insulation capabilities. <span>Furthermore</span>, MnO@C-10 wt% showed exceptional mechanical robustness, supporting a load of 57,594 times its weight, and exhibited excellent flame resistance, retaining its integrity under an alcohol lamp flame. The synergistic interaction between MnO and biomass-derived carbon offers a novel approach to developing multifunctional materials with integrated radar and infrared stealth functionalities, paving the way for advanced stealth technologies.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":null,"pages":null},"PeriodicalIF":10.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced graphitization of CO2-derived carbon anodes via Joule heating reformation for high-performance lithium-ion batteries 通过焦耳加热重整增强二氧化碳衍生碳负极的石墨化，以制造高性能锂离子电池

IF 10.5 2区材料科学

Carbon Pub Date : 2024-10-30 DOI: 10.1016/j.carbon.2024.119781

Minghao Liu , Hao Shi , Lei Guo , Zhouyu Fang , Di Chen , Wenmiao Li , Bowen Deng , Wei Li , Kaifa Du , Huayi Yin , Dihua Wang

{"title":"Enhanced graphitization of CO2-derived carbon anodes via Joule heating reformation for high-performance lithium-ion batteries","authors":"Minghao Liu , Hao Shi , Lei Guo , Zhouyu Fang , Di Chen , Wenmiao Li , Bowen Deng , Wei Li , Kaifa Du , Huayi Yin , Dihua Wang","doi":"10.1016/j.carbon.2024.119781","DOIUrl":"10.1016/j.carbon.2024.119781","url":null,"abstract":"<div><div>Molten salt electrolysis of CO<sub>2</sub> represents a promising technology for highly efficient CO<sub>2</sub> capture and the production of economically valuable CO<sub>2</sub>-derived carbon materials. In this study, we established a 100-A-scale molten salt CO<sub>2</sub> electrolysis cell to synthesize hundreds of grams of CO<sub>2</sub>-derived carbon. Subsequent Joule heating at 2800 °C transformed these materials into high-quality graphite. Further composite modification with asphalt and petroleum coke effectively reduced surface area, resulting in high-performance graphite for lithium-ion battery. The CO<sub>2</sub>-derived graphite anodes demonstrated high reversible capacities ranging from 297.7 to 378.1 mAh g<sup>−1</sup>, exhibiting outstanding rate capability and stability over 300 charge-discharge cycles at a current density of 1 A g<sup>−1</sup>. Finally, we assembled a coin full-cell using AG-2/2/6 anode and LFP cathode, which demonstrated good cycling performance. XPS analysis revealed a significant reduction in oxygen content by the post-reformation, facilitating the formation of highly graphitized structures. This study not only pioneers the up-class synthesis of CO<sub>2</sub>-derived carbon but also underscores its potential for sustainable energy applications, particularly in lithium-ion battery technology.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":null,"pages":null},"PeriodicalIF":10.5,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation into shear-thinning behavior in wet spinning of carbon nanotube fibers modeled by power law viscosity model 用幂律粘度模型研究碳纳米管纤维湿法纺丝中的剪切稀化行为

IF 10.5 2区材料科学

Carbon Pub Date : 2024-10-28 DOI: 10.1016/j.carbon.2024.119766

Jaegyun Im , Min Chan Kim , Chanwoo Park , Yun Ho Jeong , Beomjin Jeong , Kyu Hyun , Jaegeun Lee

{"title":"Investigation into shear-thinning behavior in wet spinning of carbon nanotube fibers modeled by power law viscosity model","authors":"Jaegyun Im , Min Chan Kim , Chanwoo Park , Yun Ho Jeong , Beomjin Jeong , Kyu Hyun , Jaegeun Lee","doi":"10.1016/j.carbon.2024.119766","DOIUrl":"10.1016/j.carbon.2024.119766","url":null,"abstract":"<div><div>The wet spinning of carbon nanotube (CNT) fibers, a representative solution processing of CNTs, has been advanced through the integration of well-established polymer sciences into their field. However, the flow behavior of CNT dispersions in the narrow spinning line, where its characteristics undergo changes due to the high-shear rate regime, has not been utilized to determine their spinnability, despite being a commonly employed method in the wet spinning of polymer fibers. Herein, we employed the power law viscosity model to investigate the correlation between flow behavior and the spinnability of CNT dispersion through the power law index which approaches to 0 as the shear-thinning behavior strengthens. We suggest that the spinnability of CNT dispersion is proportional to the degree of shear-thinning behavior of the dispersion. We ascribe this correlation to the integrity of CNT fibers which predominantly rely on the strong van der Waals forces between CNTs. These findings offer new insights into the role of fiber integrity in spinnability and provide a framework for optimizing the wet spinning process of CNT fibers through detailed analysis of dispersion flow behavior.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":null,"pages":null},"PeriodicalIF":10.5,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Microcrystalline cellulose-derived hard carbon for robust and low-potential sodium storage 提取自微晶纤维素的硬碳，可实现稳健的低电位钠储存

IF 10.5 2区材料科学

Carbon Pub Date : 2024-10-28 DOI: 10.1016/j.carbon.2024.119771

Chen Sun , Fei Gao , Jun-Yang Wu , Yiqiao Yang , Qiang Sun

{"title":"Microcrystalline cellulose-derived hard carbon for robust and low-potential sodium storage","authors":"Chen Sun , Fei Gao , Jun-Yang Wu , Yiqiao Yang , Qiang Sun","doi":"10.1016/j.carbon.2024.119771","DOIUrl":"10.1016/j.carbon.2024.119771","url":null,"abstract":"<div><div>Developing hard carbon with unique and regulable microstructure is the key for the development of sodium ion batteries (SIBs), while the poor low-potential sodium storage property as well as ambiguous sodium storage mechanism arising from the intricate pseudo-graphitic and graphite-like structures present a great challenge to the commercialization of SIBs. Herein, microcrystalline cellulose was proposed as carbon precursor to synthesis hard carbons by controlling carbonization temperature. As expected, the resulting hard carbons simultaneously contained pseudo-graphitic and graphite-like structures, and in situ XRD analysis suggested that a larger interlayer spacing of pseudo-graphitic structure facilitated Na<sup>+</sup> insertion, whereas smaller spacing of graphite-like structure could enhance the electrical conductivity. As a result of the optimized carbonization temperature of 1400 °C, the obtained hard carbon with larger interlayer spacing, reduced defect sites, and more closed pores, displayed an initial discharge capacity of 376.7 mA h g<sup>−1</sup> with low-potential plateau capacity ratio of 57.58 % and a high initial Coulomb efficiency of 84.32 %, while an increased plateau capacity ratio of 63.91 % in the second discharge process using an ester-based electrolyte.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":null,"pages":null},"PeriodicalIF":10.5,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Observation of thickness-independent ultrafast relaxation times in MPCVD few-layer graphene 在 MPCVD 少层石墨烯中观测到与厚度无关的超快弛豫时间

IF 10.5 2区材料科学

Carbon Pub Date : 2024-10-18 DOI: 10.1016/j.carbon.2024.119700

Tânia M. Ribeiro , Tiago E.C. Magalhães , Bohdan Kulyk , Alexandre F. Carvalho , Sebastian Nilsson , Henrik Feuk , António J.S. Fernandes , Florinda Costa , Paulo T. Guerreiro , Helder Crespo

{"title":"Observation of thickness-independent ultrafast relaxation times in MPCVD few-layer graphene","authors":"Tânia M. Ribeiro , Tiago E.C. Magalhães , Bohdan Kulyk , Alexandre F. Carvalho , Sebastian Nilsson , Henrik Feuk , António J.S. Fernandes , Florinda Costa , Paulo T. Guerreiro , Helder Crespo","doi":"10.1016/j.carbon.2024.119700","DOIUrl":"10.1016/j.carbon.2024.119700","url":null,"abstract":"<div><div>Graphene presents unique optoelectronic properties, making it attractive for the development of a wide range of new and advanced technological applications such as high-speed photodetectors and all-optical modulators. The study and control of the generated carriers in graphene, namely their ultrafast relaxation dynamics, are of great importance for these applications. Here, we report the ultrafast relaxation times of photogenerated carriers in few-layer graphene grown by microwave plasma chemical vapour deposition. Graphene samples with 3, 5 and 6 layers were studied by degenerate femtosecond optical pump-probe spectroscopy. We observed a fast relaxation constant on the order of <span><math><mrow><mn>120</mn><mo>−</mo><mn>180</mn><mspace></mspace><mi>fs</mi></mrow></math></span> and a slow relaxation constant below 1 ps, associated with carrier-carrier scattering and carrier-phonon scattering processes, respectively. These results suggest that small variations in the number of graphene layers do not affect the dynamics.</div></div>","PeriodicalId":262,"journal":{"name":"Carbon","volume":null,"pages":null},"PeriodicalIF":10.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

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