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集成有CNTs和Ni-Ni(OH)_(2)异质结构的电解析氢自支撑薄膜催化剂

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Chinese Journal of Catalysis 2024年第7期62卷 287-295页

作者：赵万成马加朋田栋康宝涛夏方诠成婧吴亚军王梦遥武刚济南大学化学化工学院山东济南250022 纽约州立大学布法罗分校化学与生物工程系纽约美国

氢气是一种重要的能量储存载体.通过电解水析氢的方式,可以将其他可再生能源转化为电能,并以化学能的形式储存于氢气中.为了提高电解析氢过程的能量转化效率、降低能耗,需要高活性的析氢催化剂.这些催化剂不仅应具有巨大的比表面积,还... 详细信息

氢气是一种重要的能量储存载体.通过电解水析氢的方式,可以将其他可再生能源转化为电能,并以化学能的形式储存于氢气中.为了提高电解析氢过程的能量转化效率、降低能耗,需要高活性的析氢催化剂.这些催化剂不仅应具有巨大的比表面积,还应具备适中的氢吸附能和较强的解离水的能力.铂基催化剂在电解析氢方面展现出了显著的优势,而同族的镍基催化剂因其高性价比而备受关注.然而,在电解析氢过程中,镍基催化剂存在氢吸附强度高和解离水能力弱两个重要缺陷,这导致析氢过程动力学不理想.因此,本文的研究思路是探索如何在镍基催化剂中引入功能性组分,以平衡氢吸附能和催化水解离的能力,从而实现析氢性能的提升.研究表明,碳纳米管(CNTs)可以改善催化剂的电解析氢性能,而Ni(OH)_(2)则可以提升催化剂解离水的能力.因此,本文采用复合电沉积法制得CNTs-Ni薄膜,并通过原位氧化在其表面形成Ni-Ni(OH)_(2)异质结构,构建了包含CNTs和Ni-Ni(OH)_(2)两种功能组分的CNTs-Ni-Ni(OH)_(2)薄膜.该薄膜展现出与Pt/C相当的析氢活性和更出色的稳定性.微观形貌分析显示,CNTs的引入使CNTs-Ni薄膜具有复杂的三维结构,镍以高度褶皱的微球形态均匀负载在CNTs表面,形成巨大的比表面积.电化学测试和模拟计算结果证实,CNTs-Ni薄膜的析氢活性较纯镍有显著提高,这归因于其巨大的电化学活性面积以及CNTs对析氢过程动力学的积极影响.当优化沉积时间和CNTs表面镍的负载量时,CNTs-Ni薄膜的电化学活性面积和析氢活性均得到显著提升.进一步氧化处理后,通过X射线光电子能谱和X射线衍射等测试手段证实了Ni-Ni(OH)_(2)异质结构的形成,并观察到电化学活性面积的增大和析氢活性的改善.此外,深入研究发现,随着氧化时间的延长,单位电化学活性面积上的析氢活性出现下降.结合析氢过程的背景电流分析推测,在析氢过程中CNTs-Ni-Ni(OH)_(2)表面发生氢氧化镍的还原,重新生成的镍活性位点对提升析氢过程动力学起到关键作用.但过长的氧化时间可能会破坏镍活性位点的再生.基于此理论构建的计算模型验证了CNTs和异质结构对析氢活性的协同增强作用,使氢的吸附自由能达到理想值,理论上氢在复合薄膜表面的析出过电位接近于0 V.因此,在碱性溶液中,集成有CNTs和Ni-Ni(OH)_(2)异质结构的CNTs-Ni-Ni(OH)_(2)析氢催化剂表现出优异的性能,其氢气起始析出电位为0 V,当阴极电流密度分别为10和50 mA/cm^(2)时,析氢过电位也仅为65和109 mV.综上所述,本文通过复合电沉积和原位氧化的方式获得了CNTs-Ni-Ni(OH)_(2)自支撑析氢催化剂,不仅体现出明显的几何效应,而且也对析氢过程的动力学产生了积极影响.这种整合多种功能性组分的方式,为未来设计和制备高活性、高性价比的电解析氢材料提供了新的思路.

关键词： Ni-Ni(OH)_(2)异质结构电解催化剂析氢反应碳纳米管吸附自由能

Re nanoclusters anchored on nanosheet supports: Formation of Re-O-matrix bonding and evaluation as all-pH-range hydrogen evolution reaction (HER) electrocatalysts

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Journal of Energy Chemistry 2022年第6期31卷 185-193,I0006页

作者： Shiyu Xu Hao Li Jeongbok Lee N.Clament Sagaya Selvam baotao kang Jin Yong Lee Pil J.Yoo School of Chemical Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea Department of Chemistry Sungkyunkwan UniversitySuwon 16419Republic of Korea

Although the water splitting-based generation of hydrogen as an energy carrier can help to mitigate the global problems of energy shortage and climate change,the practical implementation of this strategy is hindered by the absence of inexpensive high-performance electrocatalysts for the hydrogen evolution reaction (HER).Re-based HER electrocatalysts exhibit predictable high performance within the entire pH range but suffer from arduous formation (i.e.,vulnerability to oxidation) and uncontrollable aggregation,which strongly discourages the maximisation of active site exposure required for activity *** overcome these limitations,we herein hydrothermally synthesise Re nanoclusters uniformly distributed on nanosheet supports,such as reduced graphene oxide nanosheets (Re NCs@rGO),revealing that this hybrid features abundant exposed active sites and high oxidation *** obtained electrocatalysts were elaborately characterized by microscopic and spectroscopic ***,density functional theory calculations confirm the optimised synthesis of Re NCs@rGO and indicate the crucial role of Re–O–C junction formation in securing *** effective suppression of Re nanocluster detachment/dissolution under HER conditions endows Re NCs@rGO with high electron conductivity and electrochemical stability,resulting in a durability superior to that of commercial Pt/C and an activity similar to that of this *** a result,Re NCs@rGO exhibited remarkably small HER overpotentials of 110,130,and 93 m V to deliver a current density of 10 mA cm^(-2) in 0.5 M H_(2)SO_(4),1 M PBS,and 1 M KOH,***,Re NCs@rGO is a promising alternative to conventional Pt-group-metal catalysts and should find applications in next-generation high-performance water splitting systems.

关键词： Hydrogen evolution reaction(HER) Hydrothermal synthesis Re nanoclusters Nanosheet supports Electrocatalysts

Periodicity of Band Gaps of Chiral α-Graphyne Nanotubes

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Periodicity of Band Gaps of Chiral α-Graphyne Nanotubes

Bead-level characterization of early-stage amyloid β42 aggregates: nuclei and ionic concentration effects

第十三届全国量子化学会议

作者： baotao kang Fang-Fang Wang Hongqi Ai School of Chemistry and Chemical Engineering University of Jinan

Electronic structures of zigzag(n,0), armchair(n, n), and chiral(n, m)α-graph yne nanotubes(αGNTs) with n = 2.7 were investigated with densit y functional tight binding calculations. Oscil lator y behavior of the band gap with a period of ever y(n.m) = 3 was found for each tube. According to the periodicity, αGNTs could be classified into three families, and their band gaps were in increasing order of(n.m) = 3 a < 3 a+1 < 3 a+2. Among the three families, αGNTs with(n.m) = 3 a became effectivel y semimetallic if the tube size was larger than approximatel y 2 nm, while the other families remained semiconductors.

关键词： Band Gap Carbon Materials Semiconductor Semimetal

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Bead-level characterization of early-stage amyloid β42 aggr...

Effect of pH on the Structures and Properties of Aβ1-42 Oligomers and Fibrils

第十三届全国量子化学会议

作者： Dingkun Hu Wei Zhao Xiaofeng Xing Hongqi Ai Fangfang Wang baotao kang School of Chemistry and Chemical Engineering University of Jinan

Alzheimer's disease（AD） is characterized by the accumulation of insoluble fibrillar aggregates of β-amyloid peptides in the brain of AD ***,a growing body of evidence shows that soluble Aβoligomers and even protofibrils may be more neurotoxic than *** on the aggregation of Aβ oligomers and affecting factors is the cornerstone of insight into oligomers→protofibrils→mature fibrils *** we employed Martini models to simulate the aggregation processes in the early stage for 75-membered Aβ systems with and without various NaCl *** find that lower ion concentrations favor a bar-shaped morphology whereas the higher concentrations avail a flat-shaped one,suggesting a potential outline of subsequent protofibrils and mature fibrils,predicting a multi-nuclei *** from these preset nucleus systems,the aggregate composed of 75 monomers indeed becomes a spherical morphology,reproducing the extensive experimental observations and suggesting a master-nucleus *** the early aggregation,the first stage is critical as the oligomer species has emerged the shape of subsequent integral aggregate in the ***,100 mM is predicted as a critical concentration for Aβ aggregation because there is a unique twofold gap between the first positive-charged shell and the first negative-charged one（corresponding to the third shell of ions）,which producing the weakest electrostatic potential and the strongest shielding effect around the Aβ*** preset nuclei do not accelerate the aggregation rate for the early aggregation process but orient the aggregation *** most important contribution here lie in that we offer a clear scenario of ion distribution around the aggregates,from which an accurate ion-solute cutoff distance（0.656 nm） is derived and can be applied to many other aggregated *** the distribution scenario of ions can be associated directly with the Aβ aggregation evolution

关键词： Aβ aggregation ion concentration nucleus ion shells

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Effect of pH on the Structures and Properties of Aβ1-42 Oli...

Prescribed time control based on the periodic delayed sliding mode surface without singularities

第十三届全国量子化学会议

作者： Wei Zhao Dingkun Hu Xiaofeng Xing baotao kang Hongqi Ai Fangfang Wang School of Chemistry and Chemical Engineering university of jinan

Amyloid peptide(Aβ) is the key to develop AD. Experiment has confirmed that different pH influences directly the aggregation1 and morphology2 of β-Amyloid To investigate the acidi ty effect, structure changes of Aβ1-4 2 oligomer and fibril at different pH are studied in order to find both an optimal pH for aggregation and relationship between fibril morphology and pH, by using all-atom molecular dynamics simulations. Protonation states of charged residues in NT region are changed as variation of pH, whether protonated or not, accompanied by changes of electrostatic interaction between residues. We find the optimum pH for trimer and pentamer is pH 5.0 and pH 6.0 respectively, with highest β-sheet content. Both trimer and pentamer show different extent of left-twist at pH 4 to 7 and show least twist at pH 5. Besides, the twist of pentamer is more regular than trimer. The effect of acidity on oligomer structure gets smaller as the increase in aggregate chain number. Both intrachain salt-bridge and interchain salt-bridge of trimer and pentamer are affected by gradual deprotonation of E22 along with the increase of pH. As for the morphology of fibril at different pH, there is no evi dent difference among the morphology at pH 1.5/3.0/7.5

关键词： Aβ42 Oligomer Fibril pH effect

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Science China(Information Sciences) 2024年第7期67卷 256-270页

作者： Bin ZHOU Yi DING kang-kang ZHANG Guang-Ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology

In this paper, nonsingular prescribed-time control is studied based on periodic delayed sliding mode surfaces. Different from the existing sliding mode control, where either singularity problems may appear or the convergence time depends on the initial state, the proposed sliding mode control approaches can achieve prescribed-time convergence without singularity. The proposed nonsingular sliding mode control approaches can be applied to both second-order and high-order nonlinear systems with prescribed-time convergence. As applications of the proposed sliding mode control approaches, the control of hypersonic vehicle systems is revisited. Numerical simulations on the nonlinear model of the hypersonic vehicle system show the effectiveness of the proposed methods.

关键词： prescribed-time control smooth periodic delayed feedback sliding mode control high-order nonlinear systems hypersonic vehicle systems

Progress in the application of polymer fibers in solid electrolytes for lithium metal batteries

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Journal of Energy Chemistry 2024年第5期92卷 26-42页

作者： Junbao kang Nanping Deng Bowen Cheng Weimin kang State Key Laboratory of Separation Membranes and Membrane Processes/National Center for International Joint Research on Separation Membranes School of Textile Science and EngineeringTiangong UniversityTianjin 300387China

Solid state lithium metal batteries(SSLMBs)are considered to be one of the most promising battery systems for achieving high energy density and excellent safety for energy storage in the ***,current existed solid-state electrolytes(SSEs)are still difficult to meet the practical application requirements of *** this review,based on the analysis of main problems and challenges faced by the development of SSEs,the ingenious application and latest progresses including specific suggestions of various polymer fibers and their membrane products in solving these issues are emphatically ***,the inherent defects of inorganic and organic electrolytes are pointed ***,the application strategies of polymer fibers/fiber membranes in strengthening strength,reducing thickness,enhancing thermal stability,increasing the film formability,improving ion conductivity and optimizing interface stability are discussed in detail from two aspects of improving physical structure properties and electrochemical ***,the researches and development trends of the intelligent applications of high-performance polymer fibers in SSEs is *** review intends to provide timely and important guidance for the design and development of polymer fiber composite SSEs for SSLMBs.

关键词： Composite solide lectrolytes Polymer fibers Solid-state lithium metal batteries Solid-stateel ectrolytes Nanofiber membranes

Regulation of insect behavior by non-coding RNAs

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Science China(Life Sciences) 2024年第6期67卷 1106-1118页

作者： Jing He Le kang State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijing 100101China Beijing Institutes of Life Sciences Chinese Academy of SciencesBeijing 100101China College of Life Science Hebei UniversityBaoding 071002China

The adaptation of insects to environments relies on a sophisticated set of behaviors controlled by molecular and physiological *** the past several decades,accumulating studies have unveiled the roles of non-coding RNAs(nc RNAs)in regulating insect *** RNAs assume particularly pivotal roles in the behavioral plasticity of insects by rapidly responding to environmental *** RNAs also contribute to the maintenance of homeostasis of insects by fine-tuning the expression of target ***,a comprehensive review of nc RNAs'roles in regulating insect behaviors has yet to be ***,we present the recent progress in our understanding of how nc RNAs regulate various insect behaviors,including flight and movement,social behavior,reproduction,learning and memory,and *** refine the intricate mechanisms by which nc RNAs modulate the function of neural,motor,reproductive,and other physiological systems,as well as gene expression in insects like fruit flies,social insects,locusts,and ***,we discuss potential avenues for future studies in nc RNA-mediated insect behaviors.

关键词： ncRNAs insect behavior plasticity fine-tuning environmental adaptation

Considerations of advanced aqueous batteries recycling:A perspective

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Journal of Energy Chemistry 2024年第6期93卷 46-54,I0002页

作者： Yun Zhao Yuqiong kang Hao Du Feiyu kang Baohua Li Institute of Materials Research Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055GuangdongChina

*** Battery technology,serving as a basis for a rechargeable society,has developed rapidly over a century[1].The progress can be roughly divided into three stages,with the initial two mainly focusing on aqueous battery *** to 1859,research primarily focused on the conceptualization of batteries and the development of primary(non-rechargeable)cells[2].In the subsequent150 years,rechargeable battery technology emerged。

关键词： battery Battery primarily