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“Win-Win”Structural Engineering of Chinese Herb Residues-Derived Porous Graphitic Carbons:Decoupling the Porosity-Graphitization Antagonism for Ultrahigh-Rate Supercapacitors 认领 引用 被引量：1
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作者 Chuixiong Kong Tingmin Di +3 位作者 Geming Wang Quanrong Deng Yuan Gao Shenggao Wang 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2026年第2期392-404,共13页
The antagonism between porosity and graphitization critically limits carbon supercapacitor performance.Here,we demonstrate a structural engineering strategy that converts Sargentodoxa Cuneata residue(SCR)into hierarch... The antagonism between porosity and graphitization critically limits carbon supercapacitor performance.Here,we demonstrate a structural engineering strategy that converts Sargentodoxa Cuneata residue(SCR)into hierarchically porous graphitic carbons(SCR-HPCs).By precisely regulating biomass precursor porous architecture,this methodology decouples the antagonism between porosity development and graphitization progression in KOH-mediated activation,achieving simultaneous high specific surface area(2465.1 m2 g-1)and graphitization(ID/IG of 0.73).In 6 M KOH electrolyte,the specific capacitance of the optimized SCR-HPC-900 electrode reaches 415.6 F g-1 at 0.5 A g-1,with a capacitance retention of 75.1%even at an ultra-high current density of 200 A g-1.The fabricated symmetric supercapacitor achieves an energy density of 8.5 Wh kg-1 at a power density of 37803 W kg-1,retaining over 100.8%of its capacitance after 100000 cycles.Remarkably,in 1 M TEABF4/PC organic electrolyte,the supercapacitor achieves maximum energy and power densities of 45.6 Wh kg-1 and 41750 W kg-1,respectively.This study presents an effective methodology for decoupling the antagonism between porosity and graphitization in conventional processes,offering a new idea for converting biomass waste into high-performance energy storage materials. 展开更多
关键词 biomass high rate performance KOH activation porous graphitic carbon supercapacitors
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Transformative Catalytic Carbon Conversion Enabling Superior Graphitization and Nanopore Engineering in Hard Carbon Anodes for Sodium-Ion Batteries 认领 引用 被引量：6
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作者 Guilai Zhang Hong Gao +14 位作者 Dingyi Zhang Jun Xiao Limeng Sun Jiayi Li Congcong Li Yiwen Sun Xinyao Yuan Peng Huang Yi Xu Xin Guo Yufei Zhao Yong Wang Yao Xiao Guoxiu Wang Hao Liu 《Carbon Energy》 SCIE EI CSCD 2025年第6期37-46,共10页
Hard carbons are promising anode materials for sodium-ion batteries(SIBs),but they face challenges in balancing rate capability,specific capacity,and initial Coulombic efficiency(ICE).Direct pyrolysis of the precursor... Hard carbons are promising anode materials for sodium-ion batteries(SIBs),but they face challenges in balancing rate capability,specific capacity,and initial Coulombic efficiency(ICE).Direct pyrolysis of the precursor often fails to create a suitable structure for sodium-ion storage.Molecular-level control of graphitization with open channels for Na+ions is crucial for high-performance hard carbon,whereas closed pores play a key role in improving the low-voltage(<0.1 V)plateau capacity of hard carbon anodes for SIBs.However,creation of these closed pores presents significant challenges.This work proposes a zinc gluconate-assisted catalytic carbonization strategy to regulate graphitization and create numerous nanopores simultaneously.As the temperature increases,trace amounts of zinc remain as single atoms in the hard carbon,featuring a uniform coordination structure.This mitigates the risk of electrochemically irreversible sites and enhances sodium-ion transport rates.The resulting hard carbon shows an excellent reversible capacity of 348.5 mAh g-1 at 30 mA g-1 and a high ICE of 92.84%.Furthermore,a sodium storage mechanism involving“adsorption-intercalation-pore filling”is elucidated,providing insights into the pore structure and dynamic pore-filling process. 展开更多
关键词 catalytic carbonization graphitization hard carbon nanopores sodium-ion batteries
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Insights into Enhanced Capacitive Behavior of Carbon Cathode for Lithium Ion Capacitors: The Coupling of Pore Size and Graphitization Engineering 认领 引用 被引量：14
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作者 Kangyu Zou Peng Cai +6 位作者 Baowei Wang Cheng Liu Jiayang Li Tianyun Qiu Guoqiang Zou Hongshuai Hou Xiaobo Ji 《Nano-Micro Letters》 SCIE EI CAS CSCD 2020年第9期239-257,共19页
The lack of methods to modulate intrinsic textures of carbon cathode has seriously hindered the revelation of in-depth relationship between inherent natures and capacitive behaviors,limiting the advancement of lithium... The lack of methods to modulate intrinsic textures of carbon cathode has seriously hindered the revelation of in-depth relationship between inherent natures and capacitive behaviors,limiting the advancement of lithium ion capacitors(LICs).Here,an orientateddesigned pore size distribution(range from 0.5 to 200 nm)and graphitization engineering strategy of carbon materials through regulating molar ratios of Zn/Co ions has been proposed,which provides an effective platform to deeply evaluate the capacitive behaviors of carbon cathode.Significantly,after the systematical analysis cooperating with experimental result and density functional theory calculation,it is uncovered that the size of solvated PF6-ion is about 1.5 nm.Moreover,the capacitive behaviors of carbon cathode could be enhanced attributed to the controlled pore size of 1.5-3 nm.Triggered with synergistic effect of graphitization and appropriate pore size distribution,optimized carbon cathode(Zn90Co10-APC)displays excellent capacitive performances with a reversible specific capacity of^50 mAh g-1at a current density of 5 A g-1.Furthermore,the assembly pre-lithiated graphite(PLG)//Zn90Co10-APC LIC could deliver a large energy density of 108 Wh kg-1 and a high power density of 150,000 W kg-1 as well as excellent long-term ability with 10,000 cycles.This elaborate work might shed light on the intensive understanding of the improved capacitive behavior in LiPF6 electrolyte and provide a feasible principle for elaborate fabrication of carbon cathodes for LIC systems. 展开更多
关键词 Carbon materials Pore size regulation Graphitization Capacitive behavior Lithium ion capacitor
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Enhanced oxidation and graphitization resistance of polycrystalline diamond sintered with Ti-coated diamond powders 认领 引用 被引量：11
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作者 Xiaohua Sha Wen Yue +3 位作者 Haichao Zhang Wenbo Qin Dingshun She Chengbiao Wang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2020年第8期64-73,共10页
To improve the oxidation and graphitization resistances of the polycrystalline diamond(PCD), Ti coating was deposited on the diamond powders via magnetic sputtering method, which achieved a uniform Ti C protection bar... To improve the oxidation and graphitization resistances of the polycrystalline diamond(PCD), Ti coating was deposited on the diamond powders via magnetic sputtering method, which achieved a uniform Ti C protection barrier in PCD during the sintering process. The phase compositions, microstructures and thermal stability of Ti-PCD were characterized by X-ray diffraction(XRD), Auger electron spectroscopy(AES),scanning electron microscopy(SEM) and thermal gravimetric-differential scanning calorimetry(TG-DSC).The results demonstrate that the oxidation and graphitization resistances of PCD are strengthened due to the existence of Ti C phase, which acts as an effective inhibitor. The as-received inhibitor delays the oxidation and graphitization of PCD, elevating their initial temperature by ~50°C and ~100°C, respectively. During the annealing treatment of Ti-PCD, the priory oxidation of Ti C, which produces Ti O2 as an oxygen barrier, postpones the diamond oxide. Moreover, the Ti C barrier also protects diamond grains from direct contact with cobalt, thus a lower cobalt-catalytic graphitization, and yields to an improved graphitization resistance of PCD. The enhanced oxidation and graphitization resistances of PCD are of significant importance for practical applications to elevated temperatures. 展开更多
关键词 Polycrystalline diamond Ti-coated diamond powder TiC barrier Oxidation resistance Graphitization resistance
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Insight into the microstructural evolution of anthracite during carbonization-graphitization process from the perspective of materialization 认领 引用 被引量：13
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作者 Huihui Zeng Baolin Xing +7 位作者 Yijun Cao Bing Xu Lei Hou Hui Guo Song Cheng Guangxu Huang Chuanxiang Zhang Qi Sun 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2022年第6期1397-1406,共10页
Materialization of coal is one of effective and clean pathways for its utilization. The microstructures of coal-based carbon materials have an important influence on their functional applications. Herein, the microstr... Materialization of coal is one of effective and clean pathways for its utilization. The microstructures of coal-based carbon materials have an important influence on their functional applications. Herein, the microstructural evolution of anthracite in the temperature range of 1000–2800 ℃ was systematically investigated to provide a guidance for the microstructural regulation of coal-based carbon materials.The results indicate that the microstructure of anthracite undergoes an important change during carbonization-graphitization process. As the temperature increases, aromatic layers in anthracite gradually transform into disordered graphite microcrystals and further grow into ordered graphite microcrystals, and then ordered graphite microcrystals are laterally linked to form pseudo-graphite phase and eventually transformed into highly ordered graphite-like sheets. In particular, 2000–2200 ℃ is a critical temperature region for the qualitative change of ordered graphite crystallites to pseudo-graphite phase,in which the relevant structural parameters including stacking height, crystallite lateral size and graphitization degree show a rapid increase. Moreover, both aromaticity and graphitization degree have a linear positive correlation with carbonization-graphitization temperature in a specific temperature range.Besides, after initial carbonization, some defect structures in anthracite such as aliphatic carbon and oxygen-containing functional groups are released in the form of gaseous low-molecular volatiles along with an increased pore structure, and the intermediates derived from minerals could facilitate the conversion of sp3 amorphous carbon to sp2 graphitic carbon. This work provides a valuable reference for the rational design of microstructure of coal-based carbon materials. 展开更多
关键词 Anthracite Microstructural evolution Carbonization-graphitization Graphite microcrystals Materialization
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Pore structure evolution during the coke graphitization process in a blast furnace 认领 引用 被引量：10
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作者 Hao-bin Zhu Wen-long Zhan +3 位作者 Zhi-jun He Ying-chang Yu Qing-hai Pang Jun-hong Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第9期1226-1233,共8页
Pore structure is an important factor influencing coke strength,while the property of coke is essential to maintaining gas and liquid permeability in a blast furnace.Therefore,an in-depth understanding of the pore str... Pore structure is an important factor influencing coke strength,while the property of coke is essential to maintaining gas and liquid permeability in a blast furnace.Therefore,an in-depth understanding of the pore structure evolution during the graphitization process can reveal the coke size degradation behavior during its descent in a blast furnace.Coke graphitization was simulated at different heating temperatures from 1100 to 1600℃ at intervals of 100℃.The quantitative evaluation of the coke pore structure with different graphitization degree was determined by vacuum drainage method and nitrogen adsorption method.Results show that the adsorption and desorption curves of graphitized coke have intersection points,and the two curves did not coincide,instead forming a“hysteresis loop.”Based on the hysteresis loop analysis,the porous structure of the graphitized coke mostly appeared in the shape of a“hair follicle.”Furthermore,with an increase in heating temperature,the apparent porosity,specific surface area,total pore volume,and amount of micropores showed good correlation and can divided into three stages:1100-1200,1200-1400,and 1400-1600℃.When the temperature was less than 1400℃,ash migration from the inner part mainly led to changes in the coke pore structure.When the temperature was greater than 1400℃,the pore structure evolution was mainly affected by the coke graphitization degree.The results of scanning electron microscopy,energy dispersive spectrometry,and ash content analyses also confirmed that the migration of the internal ash to the surface of the matrix during the graphitization process up to 1400℃ contributed to these changes. 展开更多
关键词 coke blast furnace graphitization pore structure ash migration
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Catalytic graphitization of PAN-based carbon fibers with electrodeposited Ni-Fe alloy 认领 引用 被引量：8
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作者 周海晖 彭奇龄 +3 位作者 黄振华 余强 陈金华 旷亚非 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第3期581-587,共7页
Ni-Fe alloy was electrodeposited on the surface of polyacrylonitrile （PAN）-based carbon fibers, and catalytic graphitization effect of the heat-treated carbon fibers was investigated by X-ray diffractometry and Rama... Ni-Fe alloy was electrodeposited on the surface of polyacrylonitrile （PAN）-based carbon fibers, and catalytic graphitization effect of the heat-treated carbon fibers was investigated by X-ray diffractometry and Raman spectra. It is found that Ni-Fe alloy exhibits significant catalytic effect on the graphitization of the carbon fibers at low temperatures. The degree of graphitization of the carbon fibers coated with Ni-Fe alloy （57.91% Fe, mass fraction） reaches 69.0% through heat treatment at 1 250 °C. However, the degree of graphitization of the carbon fibers without Ni-Fe alloy is only 30.1% after being heat-treated at 2 800 °C. The catalytic effect of Ni-Fe alloy on graphitization of carbon fibers is better than that of Ni or Fe at the same temperature, indicating that Ni and Fe elements have synergic catalytic function. Furthermore, Fe content in the Ni-Fe alloy also influences catalytic effect. The catalytic graphitization of Ni-Fe alloy follows the dissolution-precipitation mechanism. 展开更多
关键词 Ni-Fe alloy electrodeposition degree of graphitization carbon fibers
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Thermodynamic and kinetic study on interfacial reaction and diamond graphitization of Cu Fe-based diamond composite 认领 引用 被引量：7
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作者 李文生 张杰 +4 位作者 董洪锋 禇克 王顺才 刘毅 李亚明 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第1期524-530,共7页
Cu-Fe based diamond composites used for saw-blade segments are directly fabricated by vacuum and pressureassisted sintering. The carbide forming elements Cr and Ti are added to improve interfacial bonding between diam... Cu-Fe based diamond composites used for saw-blade segments are directly fabricated by vacuum and pressureassisted sintering. The carbide forming elements Cr and Ti are added to improve interfacial bonding between diamond and the Cu-Fe matrix. The interfacial reactions between diamond/graphite and Cr or Ti, and diamond graphitization are investigated by thermodynamics/kinetics analyses and experimental methods. The results show that interfacial reactions and graphitization of diamond can automatically proceed thermodynamically. The Cr3C2, Cr7C3, Cr23C6, and TiC are formed at the interfaces of composites by reactions between diamond and Cr or Ti; diamond graphitization does not occur because of the kinetic difficulty at 1093 K under the pressure of 13 MPa. 展开更多
关键词 thermodynamics kinetics diamond composites diamond graphitization
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Effect of graphitization degree of fuel cell gas diffusion layers on their heat management:Modeling and experiments 认领 引用 被引量：7
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作者 WU Xiao-bo YANG Piao-piao +3 位作者 GAO Ping-ping LIU Chun-xuan XIE Zhi-yong HUANG Qi-zhong 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第1期80-88,共9页
Serving as gas diffusion layers(GDLs),the thermal conductivity of carbon paper(CP)plays a significant role in the heat transfer management in fuel cells.In the present study,the effect of graphitization degree of CP o... Serving as gas diffusion layers(GDLs),the thermal conductivity of carbon paper(CP)plays a significant role in the heat transfer management in fuel cells.In the present study,the effect of graphitization degree of CP on its through plane thermal conductivity and in-plane thermal conductivity is investigated.The relationship between heat treatment temperatures(1800,2000,2200,2400 and 2500℃)and graphitization degree is also investigated by SEM,XRD and Raman measurements.A model for CP under different graphitization degree is suggested considering the thermal conductivity difference of carbon fiber and matrix carbon.The experimental and simulation results are compared.The results show that the graphitization degree has a significant impact on the through-plane thermal conductivity and in plane thermal conductivity. 展开更多
关键词 through-plane thermal conductivity graphitization degree heat transfer carbon papers
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Effect of praseodymium on catalytic graphitization of furan resin carbon 认领 引用 被引量：4
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作者 易守军 陈金华 +2 位作者 肖雄 刘露 樊桢 《Journal of Rare Earths》 SCIE EI CAS 2010年第1期69-71,共3页
We introduced a new catalyst,rare earth element praseodymium,for the catalytic graphitization of furan resin carbon.The extent of graphitization of the furan resin carbon was examined by X-ray diffraction and Raman sp... We introduced a new catalyst,rare earth element praseodymium,for the catalytic graphitization of furan resin carbon.The extent of graphitization of the furan resin carbon was examined by X-ray diffraction and Raman spectroscopy.The morphology of furan resin carbon was characterized by scanning electron microscopy.The effects of the praseodymium content and the heat-treatment temperature on the catalytic graphitization of furan resin carbon were also investigated.The results indicated that the praseodymium c... 展开更多
关键词 catalytic graphitization praseodymium furan resin X-ray diffraction Raman spectroscopy rare earths
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Catalytic graphitization of Mo-B-doped polyacrylonitrile(PAN)-based carbon fibers 认领 引用 被引量：4
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作者 徐世海 张凤英 +2 位作者 刘绍欢 贺冬梅 蔡青云 《Journal of Central South University》 SCIE EI CAS 2010年第4期703-707,共5页
A novel carbon fiber pretreatment was proposed.Polyacrylonitrile(PAN)-based carbon fibers were first anodized in H3PO4 electrolyte to achieve an active surface,and then coated with Mo-B catalysts by immersed the carbo... A novel carbon fiber pretreatment was proposed.Polyacrylonitrile(PAN)-based carbon fibers were first anodized in H3PO4 electrolyte to achieve an active surface,and then coated with Mo-B catalysts by immersed the carbon fibers in a uniformly dispersed Mo-B sol.The as-treated carbon fibers were then graphitized at 2 400 ℃ for 2 h.The structural changes were characterized by X-ray diffractometry(XRD),Raman spectroscopy,scanning electron microscopy(SEM) and high-resolution transmission electronic microscopy(HRTEM).The results show that much better graphitization can be achieved in the presence of Mo-B,with an interlayer spacing(d002) of 0.335 8 nm and a crystalline size(Lc) of 28 nm. 展开更多
关键词 polyacrylonitrile （PAN）-based carbon fibers anodization sol catalytic graphitization Mo B
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STUDY ON THE MECHANISM OF GRAPHITIZATION IN MOLTEN CAST IRON PROMOTED BY ELECTROPULSE DISCHARGE 认领 引用 被引量：5
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作者 G.W.Chang J.S.Wang +3 位作者 J.Z.Wang Q.G.Xue O.Q.Zhou D.Q.Cang 《Acta Metallurgica Sinica(English Letters)》 EI CAS 2004年第6期790-794,共5页
From the points of both molten cast iron structure and the appearing ratio of electrons in outer-layer of different atoms, analysis on enhancement mechanism of graphitization ability after processing of the iron by pu... From the points of both molten cast iron structure and the appearing ratio of electrons in outer-layer of different atoms, analysis on enhancement mechanism of graphitization ability after processing of the iron by pulse electric discharge has been made, and the theory has been proofed by corresponding experiments. The results show that when the molten cast iron is being processed by pulse electric discharge, both the size of crystal embryos that composed by Fe and C atoms as well as the number of clusters can be reduced, even be separated by such discharging; consequently results in the segre- gation of C atoms in the molten cast iron near the cathode of discharging. The nucleation of graphite in these areas of the iron has been promoted at the discharging temperature; even though such degree has not been reached, the most favorable nucleation conditions of graphite can be at least created. Under the preconditions of not breaking up the graphite crystal embryos, with proper adjustment of discharging frequency, the stronger of the electric field and the longer of the pulsation treatment time are, the more graphitization ability of the molten cast iron is. The theoretical analysis on the above rules consists well with experimental results. 展开更多
关键词 pulsed electric field molten iron-solution graphitization
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Catalytic graphitization of polyacrylonitrile(PAN)-based carbon fibers with Fe-Cr_2O_3 composite coating 认领 引用 被引量：3
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作者 黄振华 周海晖 +2 位作者 彭奇龄 陈金华 旷亚非 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS 2010年第8期1418-1423,共6页
The process of electrodepositing Fe-Cr2O3 composite coating on polyacrylonitrile （PAN）-based carbon fibers and its catalytic graphitization were studied. Carbon fibers with and without electrodeposited Fe-Cr2O3 comp... The process of electrodepositing Fe-Cr2O3 composite coating on polyacrylonitrile （PAN）-based carbon fibers and its catalytic graphitization were studied. Carbon fibers with and without electrodeposited Fe-Cr2O3 composite coating were heat treated at different temperatures and the structural changes were characterized by XRD, Raman spectroscopy and SEM. The results indicate that Fe-Cr2O3 composite coating exhibits a significant catalytic effect on graphitization of carbon fibers at low temperatures. When the Fe-Cr2O3-coated carbon fibers were heat treated at 1 300℃ the interlayer spacing （doo2） and ratio of relative peak area （AD/AG） reach 3.364/k and 0.34, respectively. Whereas, the extent of graphitization of pristine carbon fibers is comparatively low even after heat treatment at 2 800℃ and the values of doo2 and AD/AG are 3.414 A and 0.68, respectively. The extent of graphitization of carbon fibers increases not only with the increase of the catalyst gross but also the Cr2O3 content in Fe-Cr2O3 coating. The catalytic effect of Fe-Cr2O3 composite coating accords with the dissolution-precipitation mechanism. 展开更多
关键词 carbon fiber catalytic graphitization Fe-Cr2O3 coating
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Effect of Anodization on the Graphitization of PAN-based Carbon Fibers of PAN-based Carbon Fibers 认领 引用 被引量：2
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作者 HE Dongmei YAO Yinghua +1 位作者 XU Shihai CAI Qingyun 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第5期926-930,共5页
One-step pretreatment,anodization,is used to activate the polyacrylonitrile(PAN)-based carbon fibers instead of the routine two-step pretreatment,sensitization with SnCl2 and activation with PdCl2.The effect of the an... One-step pretreatment,anodization,is used to activate the polyacrylonitrile(PAN)-based carbon fibers instead of the routine two-step pretreatment,sensitization with SnCl2 and activation with PdCl2.The effect of the anodization pretreatment on the graphitization of PAN-based carbon fibers is investigated as a function of Ni-P catalyst.The PAN-based carbon fibers are anodized in H3PO4 electrolyte resulting in the formation of active sites,which thereby facilitates the following electroless Ni-P coating.Carbon fibers in the presence and absence of Ni-P coatings are heat treated and the structural changes are characterized by X-ray diffraction and Raman spectroscopy,both of which indicate that the graphitization of PAN-based carbon fibers are accelerated by both the anodization treatment and the catalysts Ni-P.Using the anodized carbon fibers,the routine two-step pretreatment,sensitization and activation,is not needed. 展开更多
关键词 anodization X-ray diffraction raman spectroscopy graphitization
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Microstructure and graphitization behavior of diamond/SiC composites fabricated by vacuum vapor reactive infiltration 认领 引用 被引量：1
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作者 Zhen-Liang Yang Li-Gen Wang +4 位作者 Li-Min Wang Xin-Bo He Xuan-Hui Qu Rong-Jun Liu Hai-Feng Hu 《Rare Metals》 SCIE EI CAS CSCD 2015年第6期400-406,共7页
To inhibit the graphitization of diamond under high temperature and low pressure, diamond/SiC composites were firstly fabricated by a rapid gaseous Si vacuum reactive infiltration process. The microstructure and graph... To inhibit the graphitization of diamond under high temperature and low pressure, diamond/SiC composites were firstly fabricated by a rapid gaseous Si vacuum reactive infiltration process. The microstructure and graphitization behavior of diamond in the composites under various infiltration temperatures and holding time were investigated. The thermal conductivity of the resul- tant materials was discussed. The results show that the diamond-to-graphite transition is effectively inhibited at temperature of as high as 1600 ℃ under vacuum, and the substantial graphitization starts at 1700 ℃. The microstructure of those ungraphitized samples is uniform and fully densified. The inhibition mechanisms of graphitization include the isolation of the catalysts from diamond by a series of protective layers, high pressure stress applied on diamond by the reaction-bonded SiC, and the moderate gas-solid reaction. For the graphitized samples, the boundary between diamond and SiC is coarse and loose. The graphitization mechanism is considered to be an initial detachment of the bilayers from the diamond surfaces, and subsequently flattening to form graphite. The ungraphitized samples present higher thermal conductivity of about 410 W.m-1.K-1 due to the fine interfacial structure. For the graphitized samples, the thermal conductivity decreases significantly to 285 W.m-1.K-1 as a result of high interfacial thermal resistance. 展开更多
关键词 Composite Vapor reactive infiltration Microstructure Graphitization Thermal conductivity
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Effects of degree of graphitization of C shells on microwave absorption of Fe-C core-shell nanoparticles with excellent comparability 认领 引用 被引量：1
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作者 Daitao Kuang Yonghua Tian +3 位作者 Weijie Duan Zhikun Tian Xiaogang Sun Shiliang Wang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第12期1-8,共8页
In this study,Fe-C core-shell nanoparticles with identical metal core sizes and C shell thicknesses but varying degrees of graphitization of C shells were fabricated using metal-organic chemical vapor depo-sition and ... In this study,Fe-C core-shell nanoparticles with identical metal core sizes and C shell thicknesses but varying degrees of graphitization of C shells were fabricated using metal-organic chemical vapor depo-sition and subsequent annealing.Due to the identical metal core,these nanoparticles exhibite a similar permeability,but significantly varying permittivity depending on how much C shells have been graphi-tized.It was discovered that proper graphitization of Fe-C nanoparticles annealed at 1350 ℃ can pro-duce excellent microwave absorption(MA),decent dielectric loss tangent in high frequency region,and moderately strong dielectric loss and attenuation properties.Furthermore,the threshold value of 1/ω is discovered to be a crucial parameter in the theoretical analysis of nonlinear behavior of polarization loss,and thus MA performance of the nanoparticles.This research offers a useful method for creating metal-C nanoparticles with various levels of C shell graphitization.It also provides a clear answer to the crucial question of how the level of C shell graphitization affects the MA performance of metal-C nanoparticles.These results may serve as a reference for the development and mechanism analysis of highly effective metal-C based absorbers. 展开更多
关键词 Fe-C C shell Graphitization degree Microwave absorption
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Catalytic graphitization of polyacrylonitrile-based carbon fibers coated with Prussian blue 认领 引用 被引量：1
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作者 彭奇龄 周海晖 +2 位作者 黄振华 陈金华 旷亚非 《Journal of Central South University》 SCIE EI CAS 2010年第4期683-687,共5页
Prussian blue(PB) was used as catalyst to improve the extent of graphitization of polyacrylonitrile(PAN)-based carbon fibers.PB was deposited on carbon fibers by anodic electrodeposition and the thickness of PB coatin... Prussian blue(PB) was used as catalyst to improve the extent of graphitization of polyacrylonitrile(PAN)-based carbon fibers.PB was deposited on carbon fibers by anodic electrodeposition and the thickness of PB coating(PB content) was controlled by adjusting the electrodeposition time.PAN-based carbon fibers with PB coating were heat-treated and the extent of graphitization was measured by X-ray diffractometry and Raman spectroscopy.The results indicate that the extent of graphitization of PAN-based carbon fibers is enhanced in the presence of the coating.When the PB-coated carbon fibers were heat-treated at 1 900 ℃,interlayer spacing(d002) and crystallite size(Lc) reach 0.336 8 and 21.2 nm respectively.Contrarily,the values of d002 and Lc are 0.341 4 and 7.4 nm respectively when the bare carbon fibers were heat-treated at 2 800 ℃.Compared with the bare carbon fibers,PB can make the heat treatment temperature(HTT) drop more than 500 ℃ in order to reach the same extent of graphitization.Furthermore,the research results show that PB content also has a certain influence on the extent of graphitization at the same HTT. 展开更多
关键词 carbon fibers Prussian blue extent of graphitization catalyst heat treatment coating
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Preparation of lead-free free-cutting graphite brasses by graphitization of cementite 认领 引用 被引量：1
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作者 卓海鸥 唐建成 +1 位作者 薛滢妤 叶楠 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第10期3252-3257,共6页
Graphite brasses were prepared by graphitizing annealing of cast brasses containing cementite particles,which were in-situ formed during the fasting process.The eutectic cast iron as carbon source was added into commo... Graphite brasses were prepared by graphitizing annealing of cast brasses containing cementite particles,which were in-situ formed during the fasting process.The eutectic cast iron as carbon source was added into common brasses by casting.SEM and EDS were used to analyze the microstructure of graphite brasses,and the relationship between the microstructure and machinability was investigated.The results show that graphite particles are formed by the decomposition of cementite particles in cast brasses.The graphite particles are uniformly dispersed in the brass matrix with the average size of 5.0 μm and the volume fraction of ~1.1%.The machinability in the graphite brass is dramatically increased relative to the common brass,because of the lubricating properties of graphite particles and its role in chip breaking.The workpiece surface of the graphite brasses chips is smooth and burr-free,and the chips of graphite brasses are short（C-shape） and discontinuous,which is much better than that of the long spiral chips of common brasses. 展开更多
关键词 lead-free graphite brass graphitization annealing microstructure machinability
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Experimental investigation into the oxidation reactivity,morphology and graphitization of soot particles from diesel/n-octanol mixtures 认领 引用 被引量：1
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作者 Qiongyang Zhou Ying Wang +1 位作者 Xiaochen Wang Yuanqi Bai 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2022年第2期218-230,共13页
Aiming to investigate the impacts of n-octanol addition on the oxidation reactivity,morphology and graphitization of diesel exhaust particles,soot samples were collected from a four-cylinder turbocharged diesel engine... Aiming to investigate the impacts of n-octanol addition on the oxidation reactivity,morphology and graphitization of diesel exhaust particles,soot samples were collected from a four-cylinder turbocharged diesel engine fueled with D100(neat diesel fuel),DO15(85%diesel and 15%n-octanol,V/V)and DO30(70%diesel and 30%n-octanol,V/V).All tests were conducted at two engine speeds of 1370 and 2150 r/min under a fixed torque of 125 N·m.The soot properties were characterized by thermogravimetric analyzer(TGA),transmission electron microscopy(TEM)and Raman spectroscopy(RS).The higher volatile organic fraction content,lower soot oxidation temperatures and lower activation energy from TGA results indicated that both the increasing n-octanol concentration and engine speed enhanced the soot oxidation reactivity.Additionally,quantitative analysis of TEM images showed that the soot derived from DO30 had the smallest primary particle diameters and fractal dimension,followed by those of soot produced by DO15 and D100.The RS results demonstrated that the n-octanol addition and higher engine speed led to a larger D1-FWHM(D1-full width at half maximum),AD1/AT(area ratio of D1 band and the total spectral)and AD3/AT(area ratio of D3 band and the total spectral)as well as a smaller La(crystallite width),revealing a lower degree of graphitization.Furthermore,the correlations between characterization parameters of soot properties and reactivity were nonlinear. 展开更多
关键词 Oxidation reactivity Morphology Graphitization Diesel exhaust particles n-Octanol
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Surface graphitization analysis of cerium-polished HFCVD diamond films with micro-raman spectra 认领 引用 被引量：1
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作者 王树彬 孙玉静 田莳 《Journal of Rare Earths》 SCIE EI CAS 2008年第3期362-366,共5页
The etching technique using Ce is a convenient and fast method for polishing and shaping diamond films. In this study, the influence of polishing parameters such as polishing temperature and time on the surface crysta... The etching technique using Ce is a convenient and fast method for polishing and shaping diamond films. In this study, the influence of polishing parameters such as polishing temperature and time on the surface crystallinity and phase composition of diamond films was thoroughly investigated via the analysis of Raman spectra such as FWHM and ID/IG. Moreover, the issue on the graphitization of diamond after polishing with Ce was further researched through the detailed study of the depth distribution of Raman data including FWHM and ID/IG, and a result completely different from the hot-iron metal polished ones was obtained. The results showed that polished diamond films had considerably higher diamond content than those before polishing, and not a bit of graphitization was found in the polished ones, owing to a higher solubility of carbon in rare earth metal Ce than that in transition metals, and the original crystallinity of the films polished with Ce did not deteriorate. 展开更多
关键词 diamond films polishing cerium surface graphitization rare earths
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