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Boosting photocatalytic hydrogen evolution enabled by SiO_(2)-supporting chiral covalent organic frameworks with parallel stacking sequence
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作者 Zheng Lin Wanting Xie +2 位作者 Mengjing Zhu Changchun Wang Jia Guo 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第9期87-97,共11页
Two-dimensional covalent organic frameworks(2D COFs)feature extendedπ-conjugation and ordered stacking sequence,showing great promise for high-performance photocatalysis.Periodic atomic frameworks of 2D COFs facilita... Two-dimensional covalent organic frameworks(2D COFs)feature extendedπ-conjugation and ordered stacking sequence,showing great promise for high-performance photocatalysis.Periodic atomic frameworks of 2D COFs facilitate the in-plane photogenerated charge transfer,but the precise ordered alignment is limited due to the non-covalentπ-stacking of COF layers,accordingly hindering out-of-plane transfer kinetics.Herein,we address a chiral induction method to construct a parallelly superimposed stacking chiral COF ultrathin shell on the support of SiO_(2) microsphere.Compared to the achiral COF analogues,the chiral COF shell with the parallel AA-stacking structure is more conducive to enhance the built-in electric field and accumulates photogenerated electrons for the rapid migration,thereby affording superior photocatalytic performance in hydrogen evolution from water splitting.Taking the simplest ketoenamine-linked chiral COF as a shell of SiO_(2) particle,the resulting composite exhibits an impressive hydrogen evolution rate of 107.1 mmol g^(-1)h^(-1)along with the apparent quantum efficiency of 14.31% at 475 nm.Furthermore,the composite photocatalysts could be fabricated into a film device,displaying a remarkable photocatalytic performance of 178.0 mmol m^(-2)h^(-1)for hydrogen evolution.Our work underpins the surface engineering of organic photocatalysts and illustrates the significance of COF stacking structures in regulating electronic properties. 展开更多
关键词 Covalent organic framework PHOTOCATALYSIS Hydrogen generation Chiral induction Core-shell structure
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Beads-on-string hierarchical structured electrocatalysts for efficient oxygen reduction reaction 被引量:4
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作者 Yang Yuan Qing Zhang +6 位作者 Yinling Li Luyao Lv Yan Hou Ge Li Jing Fu Lin Yang Zhengyu Bai 《Carbon Energy》 SCIE CSCD 2023年第2期225-235,共11页
Rational design of hierarchically structured electrocatalysts is particularly important for electrocatalytic oxygen reduction reaction(ORR).Here,ZIF-67 crystals are stringed on core-shell Ag@C nanocables using a coord... Rational design of hierarchically structured electrocatalysts is particularly important for electrocatalytic oxygen reduction reaction(ORR).Here,ZIF-67 crystals are stringed on core-shell Ag@C nanocables using a coordinationmodulated process.Upon pyrolysis,Ag@C strings of Co nanoparticles embedded with three-dimensional porous carbon with beads-on-string hierarchical structures are developed.Due to the advantages of the rich electrochemical active sites of Co-based“beads”and the efficient electron transfer pathways via Ag@C“strings,”the resultant NH_(3)-Ag@C@Co-N-C-700 catalyst shows an improved electrocatalytic activity toward ORR.NH_(3)-Ag@C@Co-N-C-700 shows a high onset potential of 0.99 V versus RHE,a high half-wave potential of 0.88 V versus RHE,and a large limiting current of 5.8 mA cm^(-2),which are better than those of commercial Pt/C electrocatalysts.Additionally,the NH_(3)-Ag@C@Co-N-C-700 catalyst shows high stability and preeminent methanol tolerance,which makes NH_(3)-Ag@C@Co-N-C-700 a promising catalyst for oxygen electrocatalysis in fuel cell applications. 展开更多
关键词 beads-on-string structure ELECTROCATALYST metal-organic framework oxygen reduction reaction
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Charge-transfer-regulated bimetal ferrocene-based organic frameworks for promoting electrocatalytic oxygen evolution 被引量:3
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作者 Jinsong Hu Qiaoling Xu +5 位作者 Xiaoyu Wang Xinhua Huang Chunhui Zhou Ying Ye Lei Zhang Huan Pang 《Carbon Energy》 SCIE CSCD 2023年第6期60-71,共12页
The ferrocene(Fc)-based metal-organic frameworks(MOFs)are regarded as compelling platforms for the construction of efficient and robust oxygen evolution reaction(OER)electrocatalysts due to their superior conductivity... The ferrocene(Fc)-based metal-organic frameworks(MOFs)are regarded as compelling platforms for the construction of efficient and robust oxygen evolution reaction(OER)electrocatalysts due to their superior conductivity and flexible electronic structure.Herein,density functional theory simulations were addressed to predict the electronic structure regulations of CoFc-MOF by nickel doping,which demonstrated that the well-proposed CoNiFc-MOFs delivered a small energy barrier,promoted conductivity,and well-regulated d-band center.Inspired by these,a series of sea-urchin-like CoNiFc-MOFs were successfully synthesized via a facile solvothermal method.Moreover,the synchrotron X-ray and X-ray photoelectron spectroscopy measurements manifested that the introduction of nickel could tailor the electronic structure of the catalyst and induce the directional transfer of electrons,thus optimizing the rate-determining step of^(*)O→^(*)OOH during the OER process and yielding decent overpotentials of 209 and 252 mV at 10 and 200 mA cm^(−2),respectively,with a small Tafel slope of 39 mV dec^(−1).This work presents a new paradigm for developing highly efficient and durable MOF-based electrocatalysts for OER. 展开更多
关键词 density functional theory simulations electronic structure regulation hierarchical structure metal-organic frameworks oxygen evolution reaction
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Construction of all-organic low dielectric polyimide hybrids via synergistic effect between covalent organic framework and cross-linking structure 被引量:2
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作者 Wanjing Zhao Zhaoyang Wei +6 位作者 Chonghao Lu Yizhang Tong Jingshu Huang Xianwu Cao Dean Shi Robert KYLi Wei Wu 《Nano Materials Science》 EI CAS CSCD 2023年第4期429-438,共10页
Polyimide(PI)is a promising electronic packaging material,but it remains challenging to obtain an all-organic PI hybrid film with decreased dielectric constant and loss without modifying the monomer.Herein,a series of... Polyimide(PI)is a promising electronic packaging material,but it remains challenging to obtain an all-organic PI hybrid film with decreased dielectric constant and loss without modifying the monomer.Herein,a series of allorganic PI hybrid films were successfully prepared by introducing the covalent organic framework(COF),which could induce the formation of the cross-linking structure in the PI matrix.Due to the synergistic effects of the COF fillers and the cross-linking structure,the PI/COF hybrid film containing 2 wt%COF exhibited the lowest dielectric constant of 2.72 and the lowest dielectric loss(tanδ)of 0.0077 at 1 MHz.It is attributed to the intrinsic low dielectric constant of COF and a large number of mesopores within the PI.Besides,the cross-linking network of PI prevents the molecular chains from stacking and improves the fraction of free volume(FFV).The molecular dynamics simulation results are well consistent with the dielectric properties data.Furthermore,the PI/COF hybrid film with 5 wt%COF showed a significant enhancement in breakdown strength,which increased to 412.8 kV/mm as compared with pure PI.In addition,the PI/COF hybrid film achieve to reduce the dielectric constant and thermal expansion coefficient(CTE).It also exhibited excellent thermal,hydrophobicity,and mechanical performance.The all-organic PI/COF hybrid films have great commercial potential as next-generation electronic packaging materials. 展开更多
关键词 POLYIMIDE Covalent organic framework All-organic Cross-linking structure Dielectric property Hybrid film
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Tuning the electronic structure of a metal-organic framework for an efficient oxygen evolution reaction by introducing minor atomically dispersed ruthenium 被引量:2
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作者 Yuwen Li Yuhang Wu +5 位作者 Tongtong Li Mengting Lu Yi Chen Yuanjing Cui Junkuo Gao Guodong Qian 《Carbon Energy》 SCIE CSCD 2023年第2期61-71,共11页
The establishment of efficient oxygen evolution electrocatalysts is of great value but also challenging.Herein,a durable metal–organic framework(MOF)with minor atomically dispersed ruthenium and an optimized electron... The establishment of efficient oxygen evolution electrocatalysts is of great value but also challenging.Herein,a durable metal–organic framework(MOF)with minor atomically dispersed ruthenium and an optimized electronic structure is constructed as an efficient electrocatalyst.Significantly,the obtained NiRu_(0.08)-MOF with doping Ru only needs an overpotential of 187 mV at 10 mA cm^(-2) with a Tafel slop of 40 mV dec^(-1) in 0.1M KOH for the oxygen evolution reaction,and can work continuously for more than 300 h.Ultrahigh Ru mass activity is achieved,reaching 56.7 Ag^(-1)_(Ru) at an overpotential of 200 mV,which is 36 times higher than that of commercial RuO_(2).X-ray adsorption spectroscopy and density function theory calculations reveal that atomically dispersed ruthenium on metal sites in MOFs is expected to optimize the electronic structure of nickel sites,thus improving the conductivity of the catalyst and optimizing the adsorption energy of intermediates,resulting in significant optimization of electrocatalytic performance.This study could provide a new avenue for the design of efficient and stable MOF electrocatalysts. 展开更多
关键词 ELECTROCATALYSIS electronic structure metal-organic framework oxygen evolution reaction
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Inner-pore reduction nucleation of palladium nanoparticles in highly conductive wurster-type covalent organic frameworks for efficient oxygen reduction electrocatalysis 被引量:1
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作者 Weiwen Wang Lu Zhang +4 位作者 Tianping Wang Zhen Zhang Xiangnan Wang Chong Cheng Xikui Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第2期543-552,I0014,共11页
Covalent organic frameworks(COFs)have emerged as a class of promising supports for electrocatalysis because of their advantages including good crystallinity,highly ordered pores,and structural diversity.However,their ... Covalent organic frameworks(COFs)have emerged as a class of promising supports for electrocatalysis because of their advantages including good crystallinity,highly ordered pores,and structural diversity.However,their poor conductivity represents the main obstruction to their practical application.Here,we reported a novel synthesis strategy for synergistically endowing a triphenylamine-based COFs with improved electrical conductivity and excellent catalytic activity for oxygen reduction,via the in-situ redox deposition and confined growth of palladium nanoparticles inside the porous structure of COFs using reductive triphenylamine frameworks as reducing agent;meanwhile,the triphenylamine unit was oxidized to radical cation structure and affords radical cation COFs with conductivity as high as3.2*10^(-1) S m^(-1).Such a uniform confine palladium nanoparticle on highly conductive COFs makes it an efficient electrocatalyst for four-electron oxygen reduction reaction(4e-ORR),showing excellent activities and fast kinetics with a remarkable half-wave potential(E_(1/2))of 0.865 V and an ultralow Tafel slope of 39.7 mV dec^(-1) in alkaline media even in the absence of extra commercial conductive fillers.The generality of this strategy was proved by preparing the different metal and metal alloy nanoparticles supported on COFs(Au@COF,Pt@COF,AuPd@COF,AgPd@COF,and PtPd@COF)using reductive triphenylamine frameworks as reducing agent.This work not only provides a facile strategy for the fabrication of highly conductive COF supported ORR electrocatalysts,but also sheds new light on the practical application of Zn-air battery. 展开更多
关键词 Covalent organic frameworks Wurster-type structure In-situ reduction nucleation Palladium nanoparticles Oxygen reduction electrocatalysis
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Auxiliary Ligand Oriented CdⅡ-flexible Dicarboxylic Acid Coordination Frameworks:Syntheses, Structures and Properties 被引量:1
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作者 CHEN Yong-Qiang ZHAI Jia-Xin +1 位作者 TIAN Yuan LIU Xiu-Ping 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2019年第8期1311-1319,共9页
Two different CdⅡ coordination frameworks [Cd(L1)(L2)]∞(1) and [Cd(L1)-(L3)(H2O)]∞(2) based on a flexible dicarboxylic acid ligand were obtained by introducing two different nitrogen heterocyclic auxiliary ligands(... Two different CdⅡ coordination frameworks [Cd(L1)(L2)]∞(1) and [Cd(L1)-(L3)(H2O)]∞(2) based on a flexible dicarboxylic acid ligand were obtained by introducing two different nitrogen heterocyclic auxiliary ligands(L1 = 3,3’-[1,3-benzenebis(carbonylimino)]bi(benzoate), L2 = 1,3-bi(4-pyridyl)propane, L3 = 4,4’-bipyridine). Complex 1 crystallizes in triclinic, space group P■ with a = 8.7415(5), b = 12.2247(7), c =16.2415(10) ?, β = 95.6790(10)°, V = 1525.11(16) ?3, Dc = 1.553 mg·m-3, C35H28CdN4O6, Mr = 713.02, F(000) = 724, μ(MoKα) = 0.770 mm–1, Z = 2, R/wR(I > 2σ(I))a = 0.0302/0.0773. However, complex 2 crystallizes in monoclinic, space group P21/n with a = 11.4986(7), b = 23.0911(14), c = 11.9943(8) ?, β = 115.9500(10)°, V = 2863.6(3) ?3, Dc = 1.598 mg·m-3, C32H24CdN4O7, Mr = 688.96, F(000) = 1392, μ(MoKα) = 0.820 mm–1, Z = 4, R/wR(I > 2σ(I))a = 0.0283/0.0631. The structures of two complexes were characterized. Complexes 1 and 2 have different one-dimensional(1D) chain structures. In addition, we have also made a preliminary study on the properties of the two complexes. 展开更多
关键词 COORDINATION framework AUXILIARY LIGAND structure PROPERTY
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Syntheses and Structures of Two Metal-organic Frameworks Constructed from Zn/Ni and 3-Formyl-4-(pyridin-4-yl)Benzoic Acid Ligand 被引量:1
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作者 ANEES ABBAS 张杰 +3 位作者 李子建 刘燕 刘百战 崔勇 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第2期292-298,共7页
Two metal-organic frameworks [(Zn0.5L)·(H2O)]n (1) and [(Ni0.5L)?(H2O)]n (2) constructed by the 3-formyl-4-(pyridin-4-yl) benzoic acid ligand (HL) were synthesized and characterized by single-cry... Two metal-organic frameworks [(Zn0.5L)·(H2O)]n (1) and [(Ni0.5L)?(H2O)]n (2) constructed by the 3-formyl-4-(pyridin-4-yl) benzoic acid ligand (HL) were synthesized and characterized by single-crystal X-ray diffraction. 1 crystallizes in orthorhombic space group Pnna with a = 16.6152(8), b = 12.6825(6), c = 15.3908(8) A, V = 3243.2(3) ?3, Z = 4, Mr = 511.12, Dc = 1.047 g/cm3, F(000) = 1048, μ = 1.144 mm-1, GOOF = 1.061, the final R = 0.0471 and wR = 0.1262 for 12168 observed reflections with I 〉 2σ(I). 2 is isostructural to 1, which also crystallizes in orthorhombic space group Pnna with a = 16.6152(8), b = 12.6825(6), c = 15.3908(8) ?, V = 3243.2(3) ?3, Z = 4, Mr = 511.12, Dc = 1.047 g/cm3, F(000) = 1048, μ = 1.144 mm-1, GOOF = 1.061, the final R = 0.0471 and wR = 0.1262 for 12168 observed reflections with I 〉 2σ(I). Additionally, thermogravimetric analysis, FT-IR spectroscopy and powder X-ray diffraction were discussed. 展开更多
关键词 metal-organic frameworks crystal structure ZN NI FORMYL
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Recent advances in core-shell organic framework-based photocatalysts for energy conversion and environmental remediation
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作者 Qibing Dong Ximing Li +9 位作者 Yanyan Duan Qingyun Tian Xinxin Liang Yiyin Zhu Lin Tian Junjun Wang Atif Sial Yongqian Cui Ke Zhao Chuanyi Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期168-199,I0004,共33页
Direct conversion of solar energy into chemical energy in an environmentally friendly manner is one of the most promising strategies to deal with the environmental pollution and energy crisis.Among a variety of materi... Direct conversion of solar energy into chemical energy in an environmentally friendly manner is one of the most promising strategies to deal with the environmental pollution and energy crisis.Among a variety of materials developed as photocatalysts,the core-shell metal/covalent-organic framework(MOF or COF)photocatalysts have garnered significant attention due to their highly porous structure and the adjustability in both structure and functionality.The existing reviews on core-shell organic framework photocatalytic materials have mainly focused on core-shell MOF materials.However,there is still a lack of indepth reviews specifically addressing the photocatalytic performance of core-shell COFs and MOFs@COFs.Simultaneously,there is an urgent need for a comprehensive review encompassing these three types of core-shell structures.Based on this,this review aims to provide a comprehensive understanding and useful guidelines for the exploration of suitable core-shell organic framework photocatalysts towards appropriate photocatalytic energy conversion and environmental governance.Firstly,the classification,synthesis,formation mechanisms,and reasonable regulation of core-shell organic framework were summarized.Then,the photocatalytic applications of these three kinds of core-shell structures in different areas,such as H_(2)evolution,CO_(2)reduction,and pollutants degradation are emphasized.Finally,the main challenges and development prospects of core-shell organic framework photocatalysts were introduced.This review aims to provide insights into the development of a novel generation of efficient and stable core-shell organic framework materials for energy conversion and environmental remediation. 展开更多
关键词 Organic framework Core-shell structure PHOTOCATALYSIS Energy conversion Environmental remediation
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Janus Quasi‑Solid Electrolyte Membranes with Asymmetric Porous Structure for High‑Performance Lithium‑Metal Batteries
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作者 Zerui Chen Wei Zhao +4 位作者 Qian Liu Yifei Xu Qinghe Wang Jinmin Lin Hao Bin Wu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第6期221-232,共12页
Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion tran... Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion transference number(t^(+)) of liquid electrolyte confined in porous matrix remains challenging.Herein,we report a novel Janus MOFLi/MSLi QSEs with asymmetric porous structure to inherit the benefits of both mesoporous and microporous hosts.This Janus QSE composed of mesoporous silica and microporous MOF exhibits a neat Li^(+) conductivity of 1.5.10^(–4)S cm^(−1) with t^(+) of 0.71.A partially de-solvated structure and preference distribution of Li^(+)near the Lewis base O atoms were depicted by MD simulations.Meanwhile,the nanoporous structure enabled efficient ion flux regulation,promoting the homogenous deposition of Li^(+).When incorporated in Li||Cu cells,the MOFLi/MSLi QSEs demonstrated a high Coulombic efficiency of 98.1%,surpassing that of liquid electrolytes(96.3%).Additionally,NCM 622||Li batteries equipped with MOFLi/MSLi QSEs exhibited promising rate performance and could operate stably for over 200 cycles at 1 C.These results highlight the potential of Janus MOFLi/MSLi QSEs as promising candidates for next-generation LMBs. 展开更多
关键词 Metal-organic frameworks Mesoporous silicas Quasi-solid electrolytes Janus structure Lithium-metal battery
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Synthesis and structures of cdq‑topological quaternary and(4,4,8)‑c topological quinary Zn‑MOFs with both oxalic acid and triazole ligands
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作者 LIANG Jing WANG Qian BAI Junfeng 《无机化学学报》 SCIE CAS CSCD 北大核心 2024年第11期2186-2192,共7页
Different solvothermal reactions of ZnC2O_(4)with oxalic acid(H_(2)ox)and 1,2,4-triazole(Htrz)successfully gave a new quaternary(NJTU-Bai83,NJTU-Bai=Nanjing Tech University Bai's group)and a new quinary(NJTU-Bai84... Different solvothermal reactions of ZnC2O_(4)with oxalic acid(H_(2)ox)and 1,2,4-triazole(Htrz)successfully gave a new quaternary(NJTU-Bai83,NJTU-Bai=Nanjing Tech University Bai's group)and a new quinary(NJTU-Bai84)anionic metal-organic frameworks(MOFs),where NJTU-Bai83=(Me_(2)NH_(2))2[Zn_(3)(trz)_(2)(ox)_(3)]·2H_(2)O and NJTU-Bai84=(Me_(2)NH_(2))[Zn_(3)(trz)_(3)(ox)_(2)]·H_(2)O,respectively.With the[Zn_(2)(ox)4(trz)_(2)]secondary building unit(SBU)in NJTU-Bai83 replaced by the[Zn_(3)(ox)_(2)(trz)_(6)]and planar[Zn(ox)_(2)(trz)_(2)]ones in NJTU-Bai84,2D supramolecular building layers(SBLs)are changed from the A-layer and B-layer to another A-layer,while pillars are transformed from the tetrahedral[Zn(ox)_(2)(trz)_(2)]SBU to the irregular tetrahedral[Zn(ox)_(2)(trz)_(2)]and planar[Zn(ox)_(2)(trz)_(2)]SBUs.Thus,cdq-topological quaternary NJTU-Bai83 is tuned to(4,4,8)-c new topological quinary NJTU-Bai84.Two MOFs were well characterized by powder X-ray diffraction,thermogravimetric analysis,elemental analysis,etc.CCDC:2351819,NJTU-Bai83;2351820,NJTU-Bai84. 展开更多
关键词 controlled synthesis multivariant metal-organic frameworks pillar-layer typed structures
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Enhancing competency of clinical research nurses:A comprehensive training and evaluation framework
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作者 Yang-Xi Liu Yi Xu 《World Journal of Clinical Cases》 SCIE 2024年第7期1378-1381,共4页
The Sun et al's training program for clinical research nurses(CRNs)in the World Journal of Clinical Cases is a comprehensive and scientific approach.It includes structured frameworks for CRN training,aiming to imp... The Sun et al's training program for clinical research nurses(CRNs)in the World Journal of Clinical Cases is a comprehensive and scientific approach.It includes structured frameworks for CRN training,aiming to improve CRN competency.This program emphasizes practical abilities,updates training content,and improves evaluation methods.The cultivation of CRN talents focuses on enhancing the training system,establishing a multifaceted evaluation framework,and continuously refining the training programs.Regular feedback and evalua-tion are essential to improve CRNs'competency in practical settings. 展开更多
关键词 Clinical research nurse framework NURSE Operations PRACTICE structure
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A layered multifunctional framework based on polyacrylonitrile and MOF derivatives for stable lithium metal anode
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作者 Fanfan Liu Peng Zuo +5 位作者 Jing Li Pengcheng Shi Yu Shao Linwei Chen Yihong Tan Tao Ma 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期282-288,I0007,共8页
Composite Li metal anodes based on three-dimensional(3D) porous frameworks have been considered as an effective material for achieving stable Li metal batteries with high energy density.However,uneven Li deposition be... Composite Li metal anodes based on three-dimensional(3D) porous frameworks have been considered as an effective material for achieving stable Li metal batteries with high energy density.However,uneven Li deposition behavior still occurs at the top of 3D frameworks owing to the local accumulation of Li ions.To promote uniform Li deposition without top dendrite growth,herein,a layered multifunctional framework based on oxidation-treated polyacrylonitrile(OPAN) and metal-organic framework(MOF) derivatives was proposed for rationally regulating the distribution of Li ions flux,nucleation sites,and electrical conductivity.Profiting from these merits,the OPAN/carbon nano fiber-MOF(CMOF) composite framework demonstrated a reversible Li plating/stripping behavior for 500 cycles with a stable Coulombic efficiency of around 99.0% at the current density of 2 mA/cm~2.Besides,such a Li composite anode exhibited a superior cycle lifespan of over 1300 h under a low polarized voltage of 18 mV in symmetrical cells.When the Li composite anode was paired with LiFePO_(4)(LFP) cathode,the obtained full cell exhibited a stable cycling over 500 cycles.Moreover,the COMSOL Multiphysics simulation was conducted to reveal the effects on homogeneous Li ions distribution derived from the above-mentioned OPAN/CMOF framework and electrical insulation/conduction design.These electrochemical and simulated results shed light on the difficulties of designing stable and safe Li metal anode via optimizing the 3D frameworks. 展开更多
关键词 Lithium metal anode Layered multifunctional framework Ions flux redistribution Electrical insulation/conduction structure Uniform Li deposition
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Two Zn(Ⅱ)/Cd(Ⅱ)Metal-organic Frameworks Constructed from 1,3,5-Benzenetricarboxylic Acid and 1,4-Bis(1-imidazolyl)benzene:Syntheses,Structures and Photoluminescent Properties
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作者 曹壮 王记江 +4 位作者 唐龙 王潇 侯向阳 鞠萍 任宜霞 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第11期1771-1780,共10页
Two new d;metal-based metal-organic frameworks,{[Zn;(btc);(bib);(H;O);]·2H;O};(1)and{[Cd;(btc);(bib);(H;O);]·6H;O};(2)(btc=1,3,5-benzenetricarboxylate anion,bib=1,4-bis(1-imidazolyl)benzene... Two new d;metal-based metal-organic frameworks,{[Zn;(btc);(bib);(H;O);]·2H;O};(1)and{[Cd;(btc);(bib);(H;O);]·6H;O};(2)(btc=1,3,5-benzenetricarboxylate anion,bib=1,4-bis(1-imidazolyl)benzene)have been prepared under hydrothermal conditions by the reactions of d;metal oxides of ZnO and CdO with the aromatic polycarboxylic H;btc and the N-heterocyclic bib.The two products were characterized by single-crystal X-ray diffraction analysis,elemental analysis,thermogravimetric analysis(TGA),and IR spectroscopy.Complexes 1 and 2 crystallize in monoclinic C2/c and triclinic P 1 space groups,respectively.1 shows a 3D framework,and the potential large voids of the 3D network lead to a 3-fold interpenetrating architecture.2 displays a 2D framework,and the adjacent 2D layers expand into a 3D supramulecular network via rich hydrogen bonds.Moreover,the luminescent properties of the two complexes are investigated in solid state. 展开更多
关键词 Zn(Ⅱ)/Cd(Ⅱ) metal-organic frameworks crystal structure photoluminescent properties
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Structural reconstruction of Sn-based metal-organic frameworks for efficient electrochemical CO_(2) reduction to formate
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作者 Yachen Deng Shifu Wang +1 位作者 Yanqiang Huang Xuning Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第3期353-359,共7页
MOF-based materials have been widely explored in electrochemical CO_(2)reduction reactions for the production of valuable chemicals.Understanding the reconstruction of those catalysts under working conditions is cruci... MOF-based materials have been widely explored in electrochemical CO_(2)reduction reactions for the production of valuable chemicals.Understanding the reconstruction of those catalysts under working conditions is crucial for the identification of active sites and clarification of reaction mechanism.Herein,a series of six N coordinated Sn-based metal-organic frameworks(Sn-N6-MOFs)are newly developed for electrochemical CO_(2)reduction(CO_(2)RR).2%Sn-N6-MOF achieves the optimal catalytic performance with a formate Faradaic efficiency of~85%and a current density of 23 mA·cm^(-2) at-1.23 V vs.RHE.In-situ Raman results combined with ex-situ ^(119)Sn Mössbauer measurements reveal the structural reconstruction of Sn-N6-MOFs during CO_(2)RR,generating tin nanoclusters as the real active sites for CO_(2)electroreduction to HCOOH. 展开更多
关键词 structural reconstruction Metal-organic frameworks Mössbauer spectroscopy Electrochemical CO_(2)reduction
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Steric Effect Modulating the Structures of Trinuclear Zinc Carboxylate Frameworks
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作者 孙允凯 谢睿 +2 位作者 王小峰 文格波 林英武 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第9期1413-1419,共7页
By the reaction of different aromatic dicarboxylic acid with zinc nitrate, three metal-carboxylate frameworks, [Zn3(BDC)3(EtOH)2](1), [Zn3(BDC)3(py)2]·2DMF(2), and [Zn3(NH2-BDC)3(H2O)2]·5DMF... By the reaction of different aromatic dicarboxylic acid with zinc nitrate, three metal-carboxylate frameworks, [Zn3(BDC)3(EtOH)2](1), [Zn3(BDC)3(py)2]·2DMF(2), and [Zn3(NH2-BDC)3(H2O)2]·5DMF(3) which are constructed on the same linear trinuclear Zn3(RCOO)6 secondary building units, have been synthesized and characterized by X-ray diffraction analyses. Structural analyses showed that there are terephthalic acids as ligand linkers to form the hxl topological layer structures for 1 and 2. The introduction of the rigid aromatic ring pyridine in 2 as the terminal co-ligand of Zn3-SBU to instead of the flexible ethanol in 1, will form the layer-pillared supramolecular systems with 2-D crisscross channels, through its π-π stacking interactions. Owing to the steric hindrance of amino groups, 3 was assembled into a three-dimensional porous structure with pcu topology derived from the 2-amino-terephthalic acid as linkers to connect the Zn3-SBUs through a head-to-tail type. 展开更多
关键词 zinc(Ⅱ) metal-carboxylate framework steric effect crystal structure
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Recent Progress on Engineering Highly Efficient Porous Semiconductor Photocatalysts Derived from Metal–Organic Frameworks 被引量:14
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作者 Wenwen Zhan Liming Sun Xiguang Han 《Nano-Micro Letters》 SCIE EI CAS CSCD 2019年第1期5-32,共28页
Porous structures o er highly accessible surfaces and rich pores, which facilitate the exposure of numerous active sites for photocatalytic reactions, leading to excellent performances. Recently, metal–organic framew... Porous structures o er highly accessible surfaces and rich pores, which facilitate the exposure of numerous active sites for photocatalytic reactions, leading to excellent performances. Recently, metal–organic frameworks(MOFs) have been considered ideal precursors for well-designed semiconductors with porous structures and/or heterostructures, which have shown enhanced photocatalytic activities. In this review, we summarize the recent development of porous structures, such as metal oxides and metal sulfides, and their heterostructures, derived from MOF-based materials as catalysts for various light-driven energy-/environment-related reactions, including water splitting, CO_2 reduction, organic redox reaction, and pollution degradation. A summary and outlook section is also included. 展开更多
关键词 Metal–organic frameworks DERIVATIVES POROUS structure PHOTOCATALYSIS
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Regulating microstructure and composition by carbonizing in-situ grown metal-organic frameworks on cotton fabrics for boosting electromagnetic wave absorption
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作者 Jie Jin Hongsen Long +10 位作者 Hu Liu Yan Guo Tiantian Bai Ben Bin Xu Mohammed A.Amin Hua Qiu Mohamed H.Helal Chuntai Liu Changyu Shen Zeinhom M.El-Bahy Zhanhu Guo 《Nano Research》 SCIE EI CSCD 2024年第8期7290-7300,共11页
High-temperature carbonized metal-organic frameworks(MOFs)derivatives have demonstrated their superiority for promising electromagnetic wave(EMW)absorbers,but they still suffer from limited EMW absorption capacity and... High-temperature carbonized metal-organic frameworks(MOFs)derivatives have demonstrated their superiority for promising electromagnetic wave(EMW)absorbers,but they still suffer from limited EMW absorption capacity and narrow bandwidth.Considering the advantage of microstructure and chemical composition regulation for the design of EMW absorber,hierarchical heterostructured MoS_(2)/CoS_(2)-Co_(3)O_(4)@cabonized cotton fabric(CF)(MCC@CCF)is prepared by growing ZIF-67 MOFs onto CF surface,chemical etching,and carbonization.Aside from the dual loss mechanism of magnetic-dielectric multicomponent carbonized MOFs,chemical etching and carbonization process can effectively introduce abundant micro-gap structure that can result in better impedance matching and stronger absorption capacity via internal reflection,doped heteroatoms(Mo,N,S)to supply additional dipolar polarization loss,and numerous heterointerfaces among MoS_(2),CoS_(2),Co_(3)O_(4),and CCF that produce promoted conduction loss and interfacial polarization loss.Thus,a minimal reflection loss of−52.87 dB and a broadest effective absorption bandwidth of 6.88 GHz were achieved via tunning the sample thickness and filler loading,showing excellent EMW absorption performances.This research is of great value for guiding the research on MOFs derivatives based EMW absorbing materials. 展开更多
关键词 metal-organic frameworks hierarchical structure chemical etching SULFURIZATION electromagnetic wave absorption
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A tetraaldehyde-derived porous organic cage and covalent organic frameworks:Syntheses,structures,and iodine vapor capture
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作者 Xinyi Cao Yucheng Jin +5 位作者 Hailong Wang Xu Ding Xiaolin Liu Baoqiu Yu Xiaoning Zhan Jianzhuang Jiang 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第9期426-431,共6页
Dynamic covalent imine reactions between 2,3-dimethoxy-[1,1:4,1-terphenyl]-3,3,5,5-tetracarbaldehyde(DMTT)and cyclohexanediamine,p-phenylenediamine,and benzidine,respectively,generate a porous organic cage(DMPOC)and t... Dynamic covalent imine reactions between 2,3-dimethoxy-[1,1:4,1-terphenyl]-3,3,5,5-tetracarbaldehyde(DMTT)and cyclohexanediamine,p-phenylenediamine,and benzidine,respectively,generate a porous organic cage(DMPOC)and two covalent organic frameworks(COFs),USTB-29,and USTB-30.DMPOC shows a[3+6]topological cage-like structure according to single crystal X-ray diffraction result.In contrast,both microcrystalline USTB-29 and USTB-30 exhibit two-dimensional monoporous structures in an eclipsed AA stacking style based on powder X-ray diffraction and theoretical simulations.In addition,DMPOC is capable of efficiently absorbing the iodine vapor with an outstanding uptake of 5.10 g/g,much higher than that of USTB-29(3.07 g/g)and USTB-30(3.16 g/g).Cage to COFs transformations have been realized from DMPOC to USTB-29 and USTB-30 via the imine bond exchange with slightly increased iodine vapor uptake.Mechanism investigations uncover that both nitrogen and oxygen atoms of POC and COFs contribute to iodine vapor capture due to the formation of charge transfer matter,and loose interaction introducing adaptive expanding voids of DMPOC is suggested to capture more iodine vapor than that of COFs with strongπ-πinteractions. 展开更多
关键词 Porous organic cage Crystal structure Covalent organic framework Transformation Iodine vapor adsorption
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A Zinc(Ⅱ) Coordination Framework Based on Terpyridine and 5-Nitroisophthalic Acid Mixed Ligands: Synthesis, Crystal Structure and Fluorescence Property 被引量:7
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作者 陈勇强 田源 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第11期1587-1592,共6页
A new coordination framework, {[Zn(L1)(5-nipc)]·H2O}n(1, L1 = 4ˊ-(4-pyridyl)-4,2ˊ:6ˊ,4ˊˊ-terpyridine, 5-nipc = 5-nitroisophthalic acid), has been prepared under hydrothermal conditions, and determin... A new coordination framework, {[Zn(L1)(5-nipc)]·H2O}n(1, L1 = 4ˊ-(4-pyridyl)-4,2ˊ:6ˊ,4ˊˊ-terpyridine, 5-nipc = 5-nitroisophthalic acid), has been prepared under hydrothermal conditions, and determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR and powder X-ray diffraction. Complex 1 crystallizes in monoclinic, space group C2/c with a = 29.983(9), b = 13.709(3), c = 14.391(3)A, β = 114.93(4)°, V = 5364(2) A3, Dc = 1.493 g/cm^3, C28H19N5O7 Zn, Mr = 602.85, F(000) = 2464, μ(Mo Kα) = 0.972 mm^-1, Z = 8, R = 0.0935 and w R = 0.1509 for 4724 observed reflections(I 〉 2σ(I)). The structure of 1 exhibits a three-dimensional(3D) network with a layer-pillar structure. The fluorescence property of 1 is also investigated. 展开更多
关键词 coordination framework mixed-ligand approach crystal structure property
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