检索结果-南通市图书馆

Surface reconstruction and structural transformation of twodimensional Ni-Fe MOFs for oxygen evolution in seawater media

引用

Nano Research 2024年第4期17卷 2429-2437页

作者： Liyuan Xiao Xue Bai Jingyi Han Tianmi Tang Siyu Chen Hui Qi Changmin Hou Fuquan Bai Zhenlu Wang Jingqi Guan Institute of Physical chemistry College of ChemistryJilin UniversityChangchun 130021China The Second Hospital of Jilin University Changchun 130021China State Key Laboratory of Inorganic Synthesis and Preparative chemistry College of ChemistryJilin UniversityChangchun 130012China Laboratory of theoretical and Computational chemistry Institute of Theoretical ChemistryCollege of ChemistryChangchun 130023China

As a four-electron transfer reaction,oxygen evolution reaction(OER)is limited by large overpotential and slow kinetics.Here,we in-situ synthesized two-dimensional(2D)Ni-Fe metal-organic framework nanosheets on nickel foam(NixFe-TPA/NF,TPA=terephthalic acid)for oxygen evolution in alkaline and alkaline seawater electrolytes.In 1 M KOH,Ni3Fe-TPA/NF shows a low overpotential(η10)of 189 mV at 10 mA·cm^(-2) and an ultra-low overpotential of only 260 mV at 500 mA·cm^(-2).In alkaline seawater,Ni3Fe-TPA/NF still provides impressive OER performance,with anη10 of 265 mV.In-situ Raman characterization results show that the phase transition occurs during the OER,and Ni3FeOOH with more oxygen vacancies is in-situ formed,reducing the OER energy barrier.Density functional theory(DFT)reveals that the synergy between Ni and Fe reduces the energy barrier and accelerates the rate-determining step.In addition,the ultra-thin 2D sheet structure and the close combination of Ni3FeOOH and highly conductive NF support ensure the high catalytic OER activity.Therefore,the surface reconstruction and structural modification strategy can be used to design and prepare high-performance OER electrocatalysts for energy-related applications.

关键词： density functional theory(DFT)calculation Ni3FeOOH oxygen evolution reaction seawater electrolysis surface reconstruction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Kinetic network models to elucidate aggregation dynamics of aggregation-induced emission systems

Aggregate

引用

Aggregate 2024年第1期5卷 1-8页

作者： Zige Liu Michae L.Kalin Bojun Liu Siqin Cao Xuhui Huang theoretical chemistry Institute Department of ChemistryUniversity of Wisconsin-MadisonMadisonWisconsinUSA Biophysics University of Wisconsin-MadisonMadisonWisconsinUSA

Aggregation-induced emission(AIE)is a phenomenon where a molecule that is weakly or non-luminescent in a diluted solution becomes highly emissive when aggregated.AIE luminogens(AIEgens)hold promise in diverse applications like bioimaging,chemical sensing,and optoelectronics.Investigation in AIE luminescence is also critical for understanding aggregation kinetics as the aggregation process is an essential component of AIE emission.Experimental investigation of AIEgen aggregation is challenging due to the fast timescale of the aggregation and the amorphous aggregate structures.Computer simulations such as molecular dynamics(MD)simulation provide a valuable approach to complement experiments with atomic-level knowledge to study the fast dynamics of aggregation processes.However,individual simulations still struggle to systematically elucidate heterogeneous kinetics of the formation of amorphous AIEgen aggregates.Kinetic network models(KNMs),constructed from an ensemble of MD simulations,hold great potential in addressing this challenge.In these models,dynamic processes are modeled as a series ofMarkovian transitions occurring among metastable conformational states at discrete time intervals.In this perspective article,we first review previous studies to characterize the AIEgen aggregation kinetics and their limitations.We then introduce KNMs as a promising approach to elucidate the complex kinetics of aggregations to address these limitations.More importantly,we discuss our perspective on linking the output of KNMs to experimental observations of time-resolved AIE luminescence.We expect that this approach can validate the computational predictions and provide great insights into the aggregation kinetics for AIEgen aggregates.These insights will facilitate the rational design of improved AIEgens in their applications in biology and materials sciences.

关键词： hydrophobic aggregation kinetic network models molecular dynamics simulations

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A highly reduced Mo_(74) polyoxometalate featuring high proton conductivity accessed by building block strategy

引用

Science China chemistry 2024年第3期67卷 862-868页

作者： Shi-Yi Liu Xue-Xin Li Wei-Chao Chen Kui-Zhan Shao Xin-Long Wang Chao Qin Zhong-Min Su Key Laboratory of Polyoxometalate and Reticular Material chemistry of Ministry of Education Department of ChemistryNortheast Normal UniversityChangchun 130024China State Key Laboratory of Supramolecular Structure and Materials Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130021China

Highly reduced polyoxometalates(POMs) are predicted to be used as rather high energy density materials;however,it still suffers from the limited cluster species and reduction ratio.Here we demonstrate that it is possible to employ the building block strategy to generate a highly reduced polyoxomolybdate(C_(2)H_(8)N)_(14)(NH_(4))_(4)H_(14)[Mo_(48)-ⅤMo_(26)ⅥO_(202)(OH)_(12)(SO_(4))_(6)]·46H_(2)O(Mo_(74)).The fundamental Mo-based{Mo_x}(x=4,5,and 6) building blocks,which are templated by tetra-coordinated anions{MoO_(4)}or{SO_(4)},not only lay foundation for the formation of Mo_(74) featuring an unprecedented reduction ratio of 65%,but also give rise to SBBs-mediated(secondary building blocks) supramolecular dense packing interactions among the isolated Mo_(74) clusters that are favorable for proton conduction.Remarkably,high proton conductivity(2.04×10^(-2)S cm^(-1)) had been realized at 50℃ and 90% relative humidity,revealing one of the well-known POMs-based crystalline proton conducting materials.This result highlights that this building block approach possesses great potential in producing highly reduced POM systems that can achieve controllable reduced ratio and desirable properties.

关键词： polyoxometalate building block molybdenum highly reduced state proton conduction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Covalent triazine frameworks modified by ultrafine Pt nanoparticles for efficient photocatalytic hydrogen production

引用

Nano Research 2024年第6期17卷 4908-4915页

作者： Xu Han Xueying Ge Wen-Wen He Wangwang Shen Tao Zhou Jian-Sen Wang Rong-Lin Zhong Abdullah MAl-Enizi Ayman Nafady Shengqian Ma School of chemistry and Life Science Advanced Institute of Materials ScienceChangchun University of TechnologyChangchun 130012China Laboratory of theoretical and Computational chemistry Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130021China Department of chemistry University of North Texas1508 W.Mulberry St.DentonTX 76201USA Department of chemistry College of ScienceKing Saud UniversityRiyadh 11451Saudi Arabia

Pt nanoparticles(PtNPs)as active species have always been considered as one of the best semiconductor materials for photocatalytic hydrogen production.In this study,a Schottky heterojunction has been successfully constructed by evenly loading ultrafine PtNPs onto a triazine-based covalent organic frameworks(COFs).This strategy maintained the high activity of these ultra-small PtNPs while maximizing the utilization of the Pt active sites.The fabricated PtNPs@covalent triazine-based framework-1(CTF-1)composite accomplished a significantly high rate of hydrogen evolution(20.0 mmol·g^(−1)·h^(−1),apparent quantum efficiency(AQE)=7.6%,atλ=450 nm)with 0.40 wt.%Pt loading,giving rise to a 44-fold-increase in the efficiency of the photocatalytic hydrogen production compared to the pristine CTF-1.theoretical calculations revealed that the strong electron transfer(Q(Pt)=−0.726 qe,in the analysis of Bader charge,Q(Pt)is the charge quantity transferred from Pt cluster to CTF-1,and qe is the unit of charge transfer quantity)between PtNPs and CTF-1 triggers a strong interaction,which makes PtNPs being firmly attached to the structure of CTF-1,thereby enabling high stability and excellent hydrogen production efficiency.Importantly,the hydrogen binding free energy(ΔGH*)of PtNPs@CTF-1 is much lower than that of the unmodified CTF-1,leading to a much lower intermediate state and hence a significant improvement in photocatalytic performance.The overall findings of this work provide a new platform to incorporate metallic NPs into COFs for the design and fabrication of highly efficient photocatalysts.

关键词： Pt nanoparticles covalent triazine-based framework-1(CTF-1) photocatalysts hydrogen evolution reaction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Evolution exploration and structure prediction of Keggin-type group IVB metal-oxo clusters

引用

Chinese Chemical Letters 2024年第5期35卷 487-492页

作者： Run-Han Li Tian-Yi Dang Wei Guan Jiang Liu Ya-Qian Lan Zhong-Min Su School of chemistry South China Normal UniversityGuangzhou 510006China Institute of Functional Material chemistry Faculty of ChemistryNortheast Normal UniversityChangchun 130024China Institute of theoretical chemistry Jilin UniversityChangchun 130023China

The fascinating chemical structure and broad application prospect of Keggin-type polyoxometalates(POMs)have attracted many chemists to explore and discover continuously.Unlike the traditional Keggin,larger metal atomic radius,higher metal coordinated numbers,lower metal valence states and other features allow the group IVB metal-based Keggin(IVB-Keggin)more space and unknown in terms of structure and performance.Herein,density functional theory(DFT)calculations were performed to explore the influences including cores,shells,caps,and terminal ligands,et al.on IVB-Keggin,and analyze the possibility of novel structure synthesis.From the perspective of multi-layer onion-like clusters,molecular energy level,host-guest interaction energy,surface charge and covalent bond polarity can be further adjusted to achieve the oriented design of functional IVB-Keggin.These insights are expected to provide theoretical support for experimental synthesis,opening a new perspective to understand the growth of Keggin.

关键词： Keggin Metal-oxo clusters Group IVB Onion pattern DFT

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Durable poly(binaphthyl-co-p-terphenyl piperidinium)-based anion exchange membranes with dual side chains

引用

Journal of Energy chemistry 2024年第2期89卷 324-335,I0008页

作者： Weiting Gao Xuelang Gao Qiugen Zhang Aimei Zhu Qinglin Liu Department of Chemical&Biochemical Engineering Fujian Provincial Key Laboratory of Theoretical and Computational ChemistryThe College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005FujianChina Department of chemistry Pohang University of Science and Technology(POSTECH)Pohang 790-784South Korea

Building well-developed ion-conductive highways is highly desirable for anion exchange membranes(AEMs).Grafting side chain is a highly effective approach for constructing a well-defined phaseseparated morphological structure and forming unblocked ion pathways in AEMs for fast ion transport.Fluorination of side chains can further enhance phase separation due to the superhydrophobic nature of fluorine groups.However,their electronic effect on the alkaline stability of side chains and membranes is rarely reported.Here,fluorine-containing and fluorine-free side chains are introduced into the polyaromatic backbone in proper configuration to investigate the impact of the fluorine terminal group on the stability of the side chains and membrane properties.The poly(binaphthyl-co-p-terphenyl piperidinium)AEM(QBNp TP)has the highest molecular weight and most dimensional stability due to its favorable backbone arrangement among ortho-and meta-terphenyl based AEMs.Importantly,by introducing both a fluorinated piperidinium side chain and a hexane chain into the p-terphenyl-based backbone,the prepared AEM(QBNp TP-QFC)presents an enhanced conductivity(150.6 m S cm^(-1))and a constrained swelling at 80℃.The electronic effect of fluorinated side chains is contemplated by experiments and simulations.The results demonstrate that the presence of strong electro-withdrawing fluorine groups weakens the electronic cloud of adjacent C atoms,increasing OH^(-)attack on the C atom and improving the stability of piperidinium cations.Hence QBNp TP-QFC possesses a robust alkaline stability at 80℃(95.3%conductivity retention after testing in 2 M Na OH for 2160 h).An excellent peak power density of 1.44 W cm^(-2)and a remarkable durability at 80℃(4.5%voltage loss after 100 h)can be observed.

关键词： Anion exchange membranes Backbone structure Fluorinated side chain Alkaline stability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Delving into the dissimilarities in electrochemical performance and underlying mechanisms for sodium and potassium ion storage in N-doped carbon-encapsulated metallic Cu2Se nanocubes

引用

Journal of Energy chemistry 2024年第8期95卷 336-347页

作者： Xinyu Wang Yanan Xu Xiaofeng Liu Lei Tan Huaiqiang Gu Xin Du Dan Li College of chemistry Zhengzhou University Green Catalysis Center College of Chemistry Zhengzhou University Institute of theoretical Physics Lanzhou University School of Nuclear Science and Technology Lanzhou University Key Laboratory of Advanced Energy Materials chemistry(Ministry of Education) College of Chemistry Nankai University State Key Laboratory of chemistry and Utilization of Carbon Based Energy Resources College of Chemistry Xinjiang University

The large volumetric variations experienced by metal selenides within conversion reaction result in inferior rate capability and cycling stability,ultimately hindering the achievement of superior electrochemical performance.Herein,metallic Cu2Se encapsulated with N-doped carbon（Cu2Se@NC） was prepared using Cu2O nanocubes as templates through a combination of dopamine polymerization and hightemperature selenization.The unique nanocubic structure and uniform N-doped carbon coating could shorten the ion transport distance,accelerate electron/charge diffusion,and suppress volume variation,ultimately ensuring Cu2Se@NC with excellent electrochemical performance in sodium ion batteries（SIBs） and potassium ion batteries（PIBs）.The composite exhibited excellent rate performance(187.7 mA h g-1at 50 A g-1in SIBs and 179.4 mA h g-1at 5 A g-1in PIBs) and cyclic stability(246,8 mA h g-1at 10 A g-1in SIBs over 2500 cycles).The reaction mechanism of intercalation combined with conversion in both SIBs and PIBs was disclosed by in situ X-ray diffraction（XRD） and ex situ transmission electron microscope（TEM）.In particular,the final products in PIBs of K2Se and K2Se3species were determined after discharging,which is different from that in SIBs with the final species of Na2Se.The density functional theory calculation showed that carbon induces strong coupling and charge interactions with Cu2Se,leading to the introduction of built-in electric field on heterojunction to improve electron mobility.Significantly,the theoretical calculations discovered that the underlying cause for the relatively superior rate capability in SIBs to that in PIBs is the agile Na+diffusion with low energy barrier and moderate adsorption energy.These findings offer theoretical support for in-depth understanding of the performance differences of Cu-based materials in different ion storage systems.

关键词： Cu2Se nanocubes DFT calculations Ion storage mechanism Potassium ion batteries Sodium ion batteries

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Could π-aromaticity cross an unsaturated system to a fully saturated one?

引用

Chinese Chemical Letters 2024年第6期35卷 298-302页

作者： Shicheng Dong Jun Zhu State Key Laboratory of Physical chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materials(iChem)Fujian Provincial Key Laboratory of Theoretical and Computational ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China School of Science and Engineering The Chinese University of Hong KongShenzhen 518172China

The classification of π-/σ-aromaticity depends on the electrons with the dominating contributions.Traditionally,π-andσ-aromaticity are used to describe the unsaturated and saturated systems,respectively.Thus,it is rarely reported that π-aromaticity is dominated in a saturated system.Here we demonstrate that π-aromaticity could be dominating in several fully saturated four-membered rings(4MRs),supported by various aromaticity indices including ΔBL,NICS,EDDB,MCI,and Ad NDP.The origin of suchπ-aromaticity in saturated rings could be attributed to an introduction of two additional electrons into the π-type LUMO of the parent neutral species.Our findings represent a novel approach to achieve π-aromaticity into a fully saturated system which has traditionally been dominated by σ-aromaticity.

关键词： π-Aromaticity Saturated rings Silicon

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Highly active organocatalyst from a trivalent phosphazenium salt for ring-opening copolymerization of epoxides and cyclic anhydrides enhanced by hydrogen bonding interactions

引用

Science China chemistry 2024年

作者： Chunhuan Jiang Junqi Wang Xiaoyu Liu Xiaoxia You Ronglin Zhong Chuanli Ren Zhibo Li Key Laboratory of Biobased Polymer Materials Shandong Provincial Education DepartmentCollege of Polymer Science and EngineeringQingdao University of Science and Technology Laboratory of theoretical and Computational chemistry Institute of Theoretical ChemistryCollege of ChemistryJilin University College of Chemical Engineering Qingdao University of Science and Technology

It is highly desirable to develop simple organocatalysts for the controlled ring-opening alternating copolymerization （ROAC） of epoxides and cyclic anhydrides,leading to high molecular weight polyesters.Hence,a phosphazenium salt,namely tri[tris（dimethylamino）phosphoranylidenamino]phosphonium chloride （P4+Cl-）,is developed as a catalyst for the ROAC of epoxides and cyclic anhydrides.Surprisingly,the combination of P4+Cl-with a protonic initiator,such as 1,4-benzenedimethanol （BDM）exhibited high efficiency in the copolymerization of propylene oxide （PO） and phthalic anhydride （PA）.This led to the production of polyester with an exceptional high molecular weight （M_n） of up to 126 kDa,which represented a rare example of poly（PO-alt-PA） with M_n surpassing 100 k Da.Note that the core P atom is trivalent status and the tris[tris（dimethylamino）]phosphoranyl group will share one proton in the P4+Cl-salt.Once combined with protonic species,the P4+Cl-will not only serve as a proton acceptor but also as a hydrogen bonding donor for the cyclic anhydrides.Therefore,it was assumed that the P4+plus proton served dual role in mimic of base/urea pair to effectively catalyze ROAC,which was supported by density functional theory （DFT） calculations.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

From charge storage mechanism to performance:A strategy toward boosted lithium/sodium storage through heterostructure optimization

引用

Journal of Energy chemistry 2024年第1期88卷 112-124,I0003页

作者： Xiaoke Zhang Guangfa Deng Mianying Huang Zhaohui Xu Jianlin Huang Xuan Xu Zhiguang Xu Maochan Li Lei Hu Xiaoming Lin Key Laboratory of theoretical chemistry of Environment Ministry of EducationSchool of ChemistrySouth China Normal UniversityGuangzhou 510006GuangdongChina Anhui Laboratory of Functional Coordinated Complexes for Materials chemistry and Application School of Chemical and Environmental EngineeringAnhui Polytechnic UniversityWuhu 241000AnhuiChina National Engineering Research Center for Carbohydrate Synthesis Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of EducationJiangxi Normal UniversityNanchang 330022JiangxiChina

Solving the problems of low electrical conductivity and poor cycling durability in transition metal oxidesbased anode materials for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)has already turned into an urgent requirement.In this paper,we successfully synthesized Co_(2)VO_(4)/Co compounds with Co-VMOF(metal-organic framework)as a sacrificial template and investigated their electrochemical mechanism in order to improve the electrochemical properties of LIBs and SIBs.The optimized heaping configuration and the existence of metallic Co catalyzed the formation of radical ions,thereby facilitating higher conductivity,shortening Li+and Na+transport paths,and providing more active sites.Co_(2)VO_(4)/Co constructed with 2-methylimidazole as a ligand showed a discharge capacity of 1605.1 mA h g^(-1)after 300 cycles at 0.1 A g^(-1)in LIB and 677.2 mA h g^(-1)in SIB.Density functional theory(DFT)calculation emphasizes the crucial role of Co_(2)VO_(4)/Co in enhancing electrode conductivity,decreasing the migratory energy barrier,and thereby strengthening electrochemical properties.This heterostructure building technique may pave the way for the development of high-performance LIBs and SIBs.Furthermore,the problem of the low first-loop coulombic efficiency faced by transition metal oxides is improved.

关键词： Metal-organic framework Heterostructure Lithium-ion batteries Sodium-ion batteries DFT calculation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：