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Fast scanning growth of high-quality graphene films on Cu foils fueled by dimeric carbon precursor

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Nano Research 2023年第10期16卷 12246-12252页

作者： Heng Chen xiucai sun Xiaofeng Song Buhang Chen Ziteng Ma Wanjian Yin Luzhao sun Zhongfan Liu Center for Nanochemistry Beijing Science and Engineering Center for NanocarbonsBeijing National Laboratory for Molecular SciencesCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Beijing Graphene Institute Beijing 100095China College of Materials Science and Technology Beijing University of Chemical TechnologyBeijing 100029China College of Energy Soochow Institute for Energy and Materials InnovationS(SIEMIS)Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSUDA-BGI Collaborative Innovation CenterSoochow UniversitySuzhou 215006China

Carbon source precursor is a critical factor governing chemical vapor deposition growth of graphene ***(CH4),has been the most commonly used precursor in the last decade,but it presents challenges in terms of decomposition efficiency and growth *** we thoroughly evaluated acetylene(C2H_(2)),a precursor that is probably for providing carbon dimer(C2)species,for fast growth of large-scale graphene *** find that the graphene growth behaviors fueled by C2H_(2) exhibit unconventional localized growth behavior with significant advantages in terms of high growth rate,which mainly ascribe to the as-decomposed C2 ***,a C2-fueled scanning growth strategy is proposed,and the fast scanning growth rate of 40 cm/min was experimentally *** growth strategy is compatible with the approach of unidirectional growth of single-crystal graphene films,and the as-grown graphene films are of *** work demonstrates a reliable and promising strategy for the rapid synthesis of high-quality graphene film and may pave the avenue to cost-effective mass production of graphene materials in the roll-to-roll system.

关键词： graphene film chemical vapor deposition fast growth carbon dimer roll-to-roll production

Kinetics of hydrogen constrained graphene growth on Cu substrate

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Nano Research 2024年第11期17卷 9284-9292页

作者： xiucai sun Shuang Lou Weizhi Wang Xuqin Liu Xiaoli sun Yuqing Song Weimin Yang Zhongfan Liu Beijing Graphene Institute (BGI) Beijing 100095 China College of Mechanical and Electrical Engineering Beijing University of Chemical Technology Beijing 100029 China School of Instrument and Electronics North University of China Taiyuan 030051 China Center for Nanochemistry Beijing Science and Engineering Center for Nanocarbons Beijing National Laboratory for Molecular Science College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

Chemical vapor deposition (CVD) has shown great promise for the large-scale production of high-quality graphene films for industrial applications. Atomic-scale theoretical studies can help experiments to deeply understand the graphene growth mechanism, and serve as theoretical guides for further experimental designs. Here, by using density functional theory calculations, ab-initio molecular dynamics simulations, and microkinetic analysis, we systematically investigated the kinetics of hydrogen constrained graphene growth on Cu substrate. The results reveal that the actual hydrogen-rich environment of CVD results in CH as the dominating carbon species and graphene H-terminated edges. CH participated island sp2 nucleation avoids chain cyclization process, thereby improving the nucleation and preventing the formation of non-hexameric ring defects. The graphene growth is not simply C-atomic activity, rather, involves three main processes: CH species attachment at the growth edge, leading to a localized sp3 hybridized carbon at the connecting site;excess H transfer from the sp3 carbon to the newly attached CH;and finally dehydrogenation to achieve the sp2 reconstruction of the newly grown edge. The threshold reaction barriers for the growth of graphene zigzag (ZZ) and armchair (AC) edges were calculated as 2.46 and 2.16 eV, respectively, thus the AC edge grows faster than the ZZ one. Our theory successfully explained why the circumference of a graphene island grown on Cu substrates is generally dominated by ZZ edges, which is a commonly observed phenomenon in experiments. In addition, the growth rate of graphene on Cu substrates is calculated and matches well with existing experimental observations.

关键词： graphene growth chemical vapor deposition theoretical calculation Cu substrate hydrogen constraint effect

Theoretical investigations on hydroxyl carbon precursor fueled growth of graphene on transition metal substrates

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Nano Research 2024年第11期17卷 10235-10241页

作者： Chaojie Yu Haiyang Liu Xiaoli sun Jianjian Shi Zhiyu Jing xiucai sun Yuqing Song Wanjian Yin Guangping Zhang Luzhao sun Zhongfan Liu Beijing Graphene Institute Beijing 100095 China School of Physics and Electronics Shandong Normal University Jinan 250014 China Center for Nanochemistry Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering Peking University Beijing 100871 China School of Electronic Engineering Chengdu Technological University Chengdu 611730 China Academy for Advanced Interdisciplinary Research School of Instrument and Electronics North University of China Taiyuan 030051 China College of Energy Soochow Institute for Energy and Materials Innovations Soochow University Suzhou 215006 China

Transition metal catalyzed chemical vapor deposition (CVD) is considered as the most promising approach to synthesize highquality graphene films, and low-temperature growth of defect-free graphene films is long-term challenged because of the high energy barrier for precursor dissociation and graphitization. Reducing the growth temperature can also bring advantages on wrinkle-free graphene films owing to the minimized thermal expansion coefficient mismatch. This work focuses on density functional theory (DFT) calculations of the carbon source precursor with hydroxyl group, especially CH_(3)OH, on low-temperature CVD growth of graphene on Cu and CuNi substrate. We calculated all the possible cleavage paths for CH_(3)OH on transition metal substrates. The results show that, firstly, the cleavage barriers of CH_(3)OH on transition metal substrates are slightly lower than those of CH_(4), and once CO appears, it is difficult to break the C-O bond. Secondly, the CO promotes a better formation and retention of perfect rings in the early stage of graphene nucleation and reduces the edge growth barriers. Thirdly, these deoxidation barriers of CO are reduced after CO participates in graphene edge growth. This paper provides a strategy for the lowtemperature growth of wrinkles-free graphene on transition metal substrates using CH_(3)OH.

关键词： density functional theory(DFT) CH3OH Cu(111) CuNi alloys graphene chemical vapor deposition

Invisible vapor catalysis in graphene growth by chemical vapor deposition

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Nano Research 2024年第5期17卷 4259-4269页

作者： xiucai sun Xiaoting Liu Zhongti sun Xintong Zhang Yuzhu Wu Yeshu Zhu Yuqing Song Kaicheng Jia Jincan Zhang Luzhao sun Wan-Jian Yin Zhongfan Liu Center for Nanochemistry Beijing Science and Engineering Center for NanocarbonsBeijing National Laboratory for Molecular ScienceCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Beijing Graphene Institute(BGI) Beijing 100095China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China Department of Engineering University of CambridgeCambridge CB30FAUK College of Energy Soochow Institute for Energy and Materials InnovationS(SIEMIS)Jiangsu Provincial Key Laboratory for Advanced Carbon Materials and Wearable Energy TechnologiesSoochow UniversitySuzhou 215006China

Vapor catalysis was recently found to play a crucial role in superclean graphene growth via chemical vapor decomposition(CVD).However,knowledge of vapor-phase catalysis is scarce,and several fundamental issues,including vapor compositions and their impact on graphene growth,are ***,by combining density functional theory(DFT)calculations,an ideal gas model,and a designed experiment,we found that the vapor was mainly composed of Cui clusters with tens of *** vapor pressure was estimated to be~10^(-12)-10^(-1)1 bar under normal low-pressure CVD system(LPCVD)conditions for graphene growth,and the exposed surface area of Cui clusters in the vapor was 22-269 times that of the Cu substrate surface,highlighting the importance of vapor *** calculations show Cu clusters,represented by Cu17,have strong capabilities for adsorption,dehydrogenation,and decomposition of *** exhibit an adsorption lifetime and reaction flux six orders of magnitude higher than those on the Cu surface,thus providing a sufficient supply of active C atoms for rapid graphene growth and improving the surface cleanliness of the synthesized *** experimental validation showed that increasing the amount of Cu vapor improved the as-synthesized graphene growth rate and surface *** study provides a comprehensive understanding of vapor catalysis and the fundamental basis of vapor control for superclean graphene rapid growth.

关键词： vapor catalysis graphene growth chemical vapor deposition first-principles calculation

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硫对大豆叶面积和叶绿素含量的影响

东北农业大学学报 2009年第1期40卷 1-3页

作者：刘丽君孙聪姝孙秀才祖伟东北农业大学农学院哈尔滨150030

采用盆栽方法,设置4个硫素施用水平,研究硫素营养对大豆叶面积和叶片叶绿素含量的影响。结果表明,施硫能增加大豆叶面积,尤其盛花期作用效果,并显著提高开花至鼓粒期叶片叶绿素a、叶绿素b以及总叶绿素的含量,对产量形成有利。

关键词：大豆硫叶面积叶绿素

经桡动脉径路行冠状动脉介入术后不同方法压迫止血的安全性

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广州医科大学学报 2015年第2期43卷 34-37页

作者：施霞缪绯吴宏超孙秀才深圳市第三人民医院心血管内科广东深圳518112 南方医科大学珠江医院心血管内科广东广州510280

目的:探讨经桡动脉径路行冠状动脉介入术后不同方法压迫止血的安全性。方法:300例经桡动脉行冠状动脉造影患者术后随机分为3组,分别使用气囊压迫器、螺旋压迫器、绷带包扎进行桡动脉压迫止血,每组各100例。比较3组术后穿刺血管并发症发... 详细信息

目的:探讨经桡动脉径路行冠状动脉介入术后不同方法压迫止血的安全性。方法:300例经桡动脉行冠状动脉造影患者术后随机分为3组,分别使用气囊压迫器、螺旋压迫器、绷带包扎进行桡动脉压迫止血,每组各100例。比较3组术后穿刺血管并发症发生率及舒适度。结果:所有患者顺利完成冠状动脉造影,3组患者穿刺部位渗血、血肿、瘀斑,皮肤水泡、破损,桡动脉狭窄或闭塞等穿刺血管并发症发生率比较,差异无统计学意义(P>0.05);但气囊压迫器组患者肢端肿胀、麻木、发绀发生率和患者舒适度评分显著优于螺旋压迫器组和绷带包扎组(P<0.01)。结论:气囊压迫器、螺旋压迫器、绷带包扎止血成功率均较高,血管穿刺并发症发生率较低,临床应用安全、有效;其中气囊压迫器的安全性明显优于螺旋压迫器和绷带包扎。

关键词：桡动脉冠脉介入术桡动脉压迫器绷带包扎安全性

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不同硫素水平对大豆硫素含量的影响

东北农业大学学报 2006年第6期37卷 721-724页

作者：孙秀才孙聪姝刘丽君祖伟东北农业大学农学院黑龙江哈尔滨150030

文章研究了不同硫素水平对大豆硫素含量的影响。结果表明,不同品种对施硫反应不同,高蛋白品种东农42施用硫肥,籽粒硫含量并不增加,而高油品种东农46和丰产型品种合丰25施用硫肥,籽粒硫含量提高。三个品种不同器官在生育期内硫素含量变... 详细信息

文章研究了不同硫素水平对大豆硫素含量的影响。结果表明,不同品种对施硫反应不同,高蛋白品种东农42施用硫肥,籽粒硫含量并不增加,而高油品种东农46和丰产型品种合丰25施用硫肥,籽粒硫含量提高。三个品种不同器官在生育期内硫素含量变化趋势不同,籽粒硫素含量在R4-R8时期呈现为“V”型变化。

关键词：大豆硫素含量

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内蒙古甜菜制糖产业发展分析

中国糖料 2023年第2期45卷 82-90页

作者：卢秉福吴遂刘晓雪孙秀才马春慧黑龙江大学哈尔滨150080 内蒙古糖业协会呼和浩特010010 北京工商大学北京100048

中国食糖生产原料主要是甘蔗和甜菜,以甘蔗糖为主。我国食糖年产量约1050万吨,年消费量约1500万吨,不足部分依靠进口。甜菜糖生产主要分布在北方的内蒙古、新疆、黑龙江及邻近省区,年产量130万吨左右。目前内蒙古是中国最大的甜菜糖产区... 详细信息

中国食糖生产原料主要是甘蔗和甜菜,以甘蔗糖为主。我国食糖年产量约1050万吨,年消费量约1500万吨,不足部分依靠进口。甜菜糖生产主要分布在北方的内蒙古、新疆、黑龙江及邻近省区,年产量130万吨左右。目前内蒙古是中国最大的甜菜糖产区,全区共有10个盟(市)51个旗(县)种植甜菜,甜菜种植已经实现规模化、机械化,平均单产达45吨/公顷以上,高产地区单产达到75~90吨/公顷,甜菜含糖率平均15.4%,受气候等因素影响年份间差异显著,2020年甜菜收购量达到历史最高700万吨。全区现有糖厂14家,现开工12家,2020—2021年生产期产糖89.1万吨,制糖工艺损失2.3%~3.0%,呈现损失越来越低趋势。近年来受粮食作物价格上涨的影响,甜菜收购价格不断攀升,直接推升企业制糖成本上涨,导致甜菜制糖企业竞争力下降。

关键词：甜菜食糖制糖产业内蒙古

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Lajishan Ayishan Formation Rhyolites: Implications for the Closure Time of the Proto-Tethys Ocean

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Acta Geologica Sinica(English Edition) 2020年第S01期94卷 55-56页

作者： sun Yi NIU Manlan LI xiucai Hefei University of Technology HefeiAnhui230009China

The Qilian orogenic belt,as an important component of the central orogenic system,can be divided into three tectonic units from north to south:the North Qilian tectonic belt,the Central Qilian tectonic belt and the South Qilian tectonic *** Lajishan ophiolitic mélange zone is an important part of the South Qilian tectonic *** study of the formation age and tectonic attributes of the different rock units in the Lajishan is of great significance for reconstructing the tectonic evolution of the south Qilian tectonics belt and the Proto-Tethys *** Ayishan formation is an important unit of the Lajishan mélange belt,but its stratigraphic age and formation environment are still not constrained,which limits the reconstruction of the early Palaeozoic tectonic evolution of the South Qilian tectonic belt and the closure time of the Proto-Tethys *** recent years,a set of rock assemblages consisting of andesite,rhyolite,sandstone and pebbly sandstone have been identified in the Ayishan formation exposed in the Lajishan through detailed geological mapping in the *** are in fault contact with the underlying ophiolite mé***,a volcano-sedimentary succession consisting of andesite,rhyolite,volcanic breccia,and volcaniclastic sandstone nonconformably overlies the Cambrian arc-accretionarycomplex system in the Ayishan *** rocks were originally assigned to the Ayishan formation and attributed an Early Ordovician age(BGMRQP,1964,1991).Our rhyolite samples from the Ayishan formation yielded a weighted mean 206Pb/238U age of 447 Ma using zircon U-Pb dating,which can be interpreted as the eruption age of the volcanic *** volcanic rock assemblages are distributed in sandstone,pebbled sandstone and conglomerate in the form of ***,the zircon UPb age of the volcanic rocks can constrain the age of Ayishan formation that it should belong to the late Ordovician rather than early ***,we propose that the Ay

关键词： Lajishan rhyolite Proto-Tethys Ocean South Qilian