期刊文献+
共找到40,001篇文章
< 1 2 250 >
每页显示 20 50 100
Synthesis,structures,and properties of metal-organic frameworks based on bipyridyl ligands and isophthalic acid 被引量:1
1
作者 HOU Jimin LI Mengyang +4 位作者 GONG Chunhua ZHANG Shaozhuang ZHAN Caihong XU Hao XIE Jingli 《无机化学学报》 北大核心 2025年第3期549-560,共12页
(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under... (2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under solvothermal conditions,to react with transition metals achieving four novel metal-organic frameworks(MOFs):[Zn(IP)(L_(1))]_(n)(1),{[Cd(IP)(L_(1))]·H_(2)O}_(n)(2),{[Co(IP)(L_(1))]·H_(2)O}_(n)(3),and[Zn(IP)(L_(2))(H_(2)O)]_(n)(4).MOFs 1-4 have been characterized by single-crystal X-ray diffraction,powder X-ray diffraction,thermogravimetry,and elemental analysis.Single-crystal X-ray diffraction shows that MOF 1 crystallizes in the monoclinic crystal system with space group P2_(1)/n,and MOFs 2-4 belong to the triclinic system with the P1 space group.1-3 are 2D sheet structures,2 and 3 have similar structural characters,whereas 4 is a 1D chain structure.Furthermore,1-3 exhibited certain photocatalytic capability in the degradation of rhodamine B(Rh B)and pararosaniline hydrochloride(PH).4could be used as a heterogeneous catalyst for the Knoevenagel reaction starting with benzaldehyde derivative and malononitrile.4 could promote the reaction to achieve corresponding products in moderate yields within 3 h.Moreover,the catalyst exhibited recyclability for up to three cycles without significantly dropping its activity.A mechanism for MOF 4 catalyzed Knoevenagel condensation reaction of aromatic aldehyde and malononitrile has been initially proposed.CCDC:2356488,1;2356497,2;2356499,3;2356498,4. 展开更多
关键词 bipyridyl ligands metal⁃organic frameworks photocatalytic degradation Knoevenagel condensation
在线阅读 下载PDF
An Empirical Study on the Reflective Feedback Model Based on Pedagogical Agents to Improve Students’ Problem-Solving Ability 被引量:1
2
作者 Hui-Lin Zhang Jun-Jie Yan +4 位作者 Jing Liu Zhuo-Cen Zou Qun-Fang Zeng Yu-Lu Jin Jian-Nan Wu 《教育技术与创新》 2025年第1期66-75,共10页
This study constructs a reflective feedback model based on a pedagogical agent(PA)and explores its impact on students’problem-solving ability and cognitive load.A quasi-experimental design was used in the study,with ... This study constructs a reflective feedback model based on a pedagogical agent(PA)and explores its impact on students’problem-solving ability and cognitive load.A quasi-experimental design was used in the study,with 84 students from a middle school selected as the research subjects(44 in the experimental group and 40 in the control group).The experimental group used the reflective feedback model,while the control group used the factual feedback model.The results show that,compared with factual feedback,the reflective feedback model based on the pedagogical agent significantly improves students’problem-solving ability,especially at the action and thinking levels.In addition,this model effectively reduces students’cognitive load,especially in terms of internal and external load. 展开更多
关键词 pedagogical agent problem-solving ability reflective feedback
在线阅读 下载PDF
Radiation reduction modification of sp^(2) carbon-conjugated covalent organic frameworks for enhanced photocatalytic chromium(Ⅵ) removal 被引量:1
3
作者 Shouchao Zhong Yue Wang +6 位作者 Mingshu Xie Yiqian Wu Jiuqiang Li Jing Peng Liyong Yuan Maolin Zhai Weiqun Shi 《Chinese Chemical Letters》 2025年第5期277-282,共6页
A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for ... A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for Cr(Ⅵ) removal.The morphology and structure of rBDATN-HCl were analyzed and identified by SEM,FTIR,XRD and solid-state13C NMR.It is found that the active functional groups,such as hydroxyl and amide,were introduced into BDATN after radiation reduction and acidification.The prepared rBDATN-HCl demonstrates a photocatalytic reduction removal rate of Cr(Ⅵ) above 99%after 60min of illumination with a solid-liquid ratio of 0.5 mg/mL,showing outstanding performance,which is attributed to the increase of dispersibility and adsorption sites of r BDATN-HCl.In comparison to the cBDATN-HCl synthesized with chemical reduction,rBDATN-HCl exhibits a better photoreduction performance for Cr(Ⅵ),demonstrating the advantages of radiation preparation of rBDATN-HCl.It is expected that more functionalized sp^(2) carbon-conjugated COFs could be obtained by this radiation-induced reduction strategy. 展开更多
关键词 Covalent organic framework Gamma radiation Photocatalytic reduction CHROMIUM Water purification
原文传递
In situ preparation of zincophilic covalent-organic frameworks with low surface work function and high rigidity to stabilize zinc metal anodes 被引量:1
4
作者 Yunyu Zhao Kaiyong Feng Yingjian Yu 《Journal of Energy Chemistry》 2025年第3期524-533,共10页
Zinc-ion batteries(ZIBs)are inexpensive and safe,but side reactions on the Zn anode and Zn dendrite growth hinder their practical applications.In this study,1,3,5-triformylphloroglycerol(Tp)and various diamine monomer... Zinc-ion batteries(ZIBs)are inexpensive and safe,but side reactions on the Zn anode and Zn dendrite growth hinder their practical applications.In this study,1,3,5-triformylphloroglycerol(Tp)and various diamine monomers(p-phenylenediamine(Pa),benzidine(BD),and 4,4"-diamino-p-terphenyl(DATP))were used to synthesize a series of two-dimensional covalent-organic frameworks(COFs).The resulting COFs were named TpPa,TpBD,and TpDATP,respectively,and they showed uniform zincophilic sites,different pore sizes,and high Young's moduli on the Zn anode.Among them,TpPa and TpBD showed lower surface work functions and higher ion transfer numbers,which were conducive to uniform galvanizing/stripping zinc and inhibited dendrite growth.Theoretical calculations showed that TpPa and TpBD had wider negative potential region and greater adsorption capacity for Zn2+than TpDATP,providing more electron donor sites to coordinate with Zn^(2+).Symmetric cells protected by TpPa and TpBD stably cycled for more than 2300 h,whereas TpDATP@Zn and the bare zinc symmetric cells failed after around 150 and200 h.The full cells containing TpPa and TpBD modification layers also showed excellent cycling capacity at 1 A/g.This study provides comprehensive insights into the construction of highly reversible Zn anodes via COF modification layers for advanced rechargeable ZIBs. 展开更多
关键词 Zn ion batteries Covalent organic framework DENDRITE Low surface work function High rigidity
在线阅读 下载PDF
Construction of 3D porous Cu_(1.81)S/nitrogen-doped carbon frameworks for ultrafast and long-cycle life sodium-ion storage
5
作者 Chen Chen Hongyu Xue +6 位作者 Qilin Hu Mengfan Wang Pan Shang Ziyan Liu Tao Peng Deyang Zhang Yongsong Luo 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期191-200,共10页
Transition metal sulfides have great potential as anode mterials for sodium-ion batteries(SIBs)due to their high theoretical specific capacities.However,the inferior intrinsic conductivity and large volume variation d... Transition metal sulfides have great potential as anode mterials for sodium-ion batteries(SIBs)due to their high theoretical specific capacities.However,the inferior intrinsic conductivity and large volume variation during sodiation-desodiation processes seriously affect its high-rate and long-cyde performance,unbeneficial for the application as fast-charging and long-cycling SIBs anode.Herein,the three-dimensional porous Cu_(1.81)S/nitrogen-doped carbon frameworks(Cu_(1.81)S/NC)are synthesized by the simple and facile sol-gel and annealing processes,which can accommodate the volumetric expansion of Cu_(1.81)S nanoparticles and accelerate the transmission of ions and electrons during Na^(+)insertion/extraction processes,exhibiting the excellent rate capability(250.6 mA·g^(-1)at 20.0 A·g^(-1))and outstanding cycling stability(70% capacity retention for 6000 cycles at 10.0 A·g^(-1))for SIBs.Moreover,the Na-ion full cells coupled with Na_(3)V_(2)(PO_(4))_(3)/C cathode also demonstrate the satisfactory reversible specific capacity of 330.5 mAh·g^(-1)at 5.0 A·g^(-1)and long-cycle performance with the 86.9% capacity retention at 2.0 A·g^(-1)after 750 cycles.This work proposes a promising way for the conversionbased metal sulfides for the applications as fast-charging sodium-ion battery anode. 展开更多
关键词 copper sulfide nanoparticles porous carbon framework fast charging long-cycle performance sodium-ion full batteries
在线阅读 下载PDF
Pyridine-nitrogen conjugated covalent organic frameworks for high-efficiency gas-solid photocatalytic reduction of CO_(2)to CO 被引量:1
6
作者 Haicheng Jiang Chi Cao +10 位作者 Wei Liu Hao Zhang Qianyu Li Siyuan Zhu Xiaoning Li Jinshuo Li Jinfa Chang Wei Hu Zihao Xing Xiaoqin Zou Guangshan Zhu 《Journal of Energy Chemistry》 2025年第5期127-135,共9页
The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Cova... The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Covalent organic frameworks(COFs)offer a promising approach for CO_(2)transformation but lack high efficiency and selectivity in the absence of metals.Here,we have incorporated a pyridine nitrogen component into the imine-COF conjugated structure(Tp Pym).This innovative system has set a record of producing a CO yield of 1565μmol g^(-1)within 6 h.The soft X-ray absorption fine structure measurement proves that Tp Pym has both better conjugation and electron cloud enrichment.The electronic structure distribution delays the charge-carrier recombination,as evidenced by femtosecond transient absorption spectroscopy.The energy band diagram and theoretical calculation show that the conduction-band potential of Tp Pym is lower and the reduction reaction of CO_(2)to CO is more likely to occur. 展开更多
关键词 Light-driven CO_(2)reduction Gas-solid reaction Conjugated pyridine nitrogen Covalent organic framework CO_(2)catalysis to CO
在线阅读 下载PDF
Syntheses,crystal structures,and diametrically opposed mechanically-stimulated luminescence response of two Mg(Ⅱ)metal-organic frameworks
7
作者 CHEN Yukun FENG Kexin +2 位作者 ZHANG Bolun SONG Wentao ZHANG Jianjun 《无机化学学报》 北大核心 2025年第6期1227-1234,共8页
The reaction of Mg^(2+)and 5-{1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl}terephthalic acid(H_(2)L)leads to two metal-organic frameworks,[Mg(L)(DMF)_(2)(H_(2)O)_(2)]_(2)·5DMF·2H_(2)O(1)with a 1D structure and... The reaction of Mg^(2+)and 5-{1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl}terephthalic acid(H_(2)L)leads to two metal-organic frameworks,[Mg(L)(DMF)_(2)(H_(2)O)_(2)]_(2)·5DMF·2H_(2)O(1)with a 1D structure and[Mg_(2)(L)_(2)(DMSO)_(3)(H_(2)O)](2)with a 2D(4,4)-net structure.Interestingly,the two compounds exhibit distinct luminescent responses to external mechanical stimuli.1 exhibited exceptional resistance mechanical chromic luminescence(RMCL),which can be attributed to the predominant hydrogen bonds and the presence of high-boiling-point solvent molecules within its structure.2 had a reversible MCL property,which can be attributed to the dominantπ-πweak interactions,coupled with the reversible destruction/restoration of its crystallinity under grinding/fumigation.CCDC:2410963,1;2410964,2. 展开更多
关键词 metal-organic framework crystal structure mechanical chromic luminescence resistance mechanical chromic luminescence weak interaction
在线阅读 下载PDF
Advances in selective hydrogenation ofα,β‑unsaturated aldehydes/ketones catalyzed by metal‑organic frameworks and their derivatives:A review
8
作者 YANG Jiaxuan DENG Chenfa +7 位作者 LIU Jingyang XU Chenzexi CHEN Hongxin ZHU Yahui LI Ying WANG Shuhua ZHOU Rongping CHEN Chao 《无机化学学报》 北大核心 2025年第10期1973-2010,共38页
The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively red... The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively reduce C=C or C=O bonds while preserving other functional groups within the molecule.This approach serves as a critical strategy for the directional synthesis of high-value molecules.However,achieving such selectivity remains challenging due to the thermodynamic equilibrium and kinetic competition between C=O and C=C bonds inα,β-unsaturated systems.Consequently,constructing precisely targeted catalytic systems is essential to overcome these limitations,offering both fundamental scientific significance and industrial application potential.Metal-organic frameworks(MOFs)and their derivatives have emerged as innovative platforms for designing such systems,owing to their programmable topology,tunable pore microenvironments,spatially controllable active sites,and modifiable electronic structures.This review systematically summarizes the research progress of MOF-based catalysts for selec-tive hydrogenation ofα,β-unsaturated aldehydes/ketones in the last decade,with emphasis on the design strategy,conformational relationship,and catalytic mechanism,aiming to provide new ideas for the design of targeted catalyt-ic systems for the selective hydrogenation ofα,β-unsaturated aldehydes/ketones. 展开更多
关键词 α β-unsaturated aldehydes/ketones metal-organic frameworks DERIVATIVES selective hydrogenation catalytic mechanism hydrogenation path
在线阅读 下载PDF
Recent advances in zeolitic imidazolate frameworks as drug delivery systems for cancer therapy
9
作者 Yuhan Wang Yixin Tang +4 位作者 Lei Guo Xi Yang Shanli Wu Ying Yue Caina Xu 《Asian Journal of Pharmaceutical Sciences》 2025年第1期94-118,共25页
Biological nanotechnologies based on functional nanoplatforms have synergistically catalyzed the emergence of cancer therapies.As a subtype of metal-organic frameworks(MOFs),zeolitic imidazolate frameworks(ZIFs)have e... Biological nanotechnologies based on functional nanoplatforms have synergistically catalyzed the emergence of cancer therapies.As a subtype of metal-organic frameworks(MOFs),zeolitic imidazolate frameworks(ZIFs)have exploded in popularity in the field of biomaterials as excellent protective materials with the advantages of conformational flexibility,thermal and chemical stability,and functional controllability.With these superior properties,the applications of ZIF-based materials in combination with various therapies for cancer treatment have grown rapidly in recent years,showing remarkable achievements and great potential.This review elucidates the recent advancements in the use of ZIFs as drug delivery agents for cancer therapy.The structures,synthesis methods,properties,and various modifiers of ZIFs used in oncotherapy are presented.Recent advances in the application of ZIF-based nanoparticles as single or combination tumor treatments are reviewed.Furthermore,the future prospects,potential limitations,and challenges of the application of ZIF-based nanomaterials in cancer treatment are discussed.We except to fully explore the potential of ZIF-based materials to present a clear outline for their application as an effective cancer treatment to help them achieve early clinical application. 展开更多
关键词 Metal-organic frameworks(MOFs) Zeolitic imidazolate frameworks(ZIF-8) ZIF-based nanoparticles Drug delivery Cancer treatment
暂未订购
Hematopoietic responses to metal-organic frameworks in adult mice following pulmonary exposure
10
作者 Min Li Linlin Yao +10 位作者 Yuanyuan Wang Jie Gao Junjie Ma Yaquan Liu Yun Ding Xuehan Zheng Liqun Chen Runzeng Liu Li Zeng Guangbo Qu Guibin Jiang 《Journal of Environmental Sciences》 2025年第10期30-41,共12页
Themetal-organic frameworks(MOFs)MIL-100 andNH2-MIL-125 have hierarchical structure pores with high adsorption capacities and have therefore been suggested for drug delivery,gas storage,catalysis and chemical sensing.... Themetal-organic frameworks(MOFs)MIL-100 andNH2-MIL-125 have hierarchical structure pores with high adsorption capacities and have therefore been suggested for drug delivery,gas storage,catalysis and chemical sensing.The widespread applications of these MOFs raise concerns about the possible release into the environment and subsequent human exposure.Yet,the available knowledge of the toxicity of these MOFs is rather scarce despite the encouraging applications.Here,we investigated the hematopoietic effects in different organs induced by MIL-100 and NH_(2)-MIL-125 in mice after intratracheal instillation.The hematopoietic cells in the bonemarrow(BM),lungs,and spleen were analyzed through flow cytometry method.Compared to NH2-MIL-125,MIL-100 triggered changes in more types of hematopoietic cells in the BM and spleen,but comparable changes in the lungs.In the BM and lungs,both the twoMOFs suppressedmyelopoiesis on day 1,but promotedmyelopoiesis on day 7.In the spleen,by contrast,continuous suppressedmyelopoiesis were found on day 1 and day 7.Moreover,changes in megakaryocyte progenitors(MkPs)were only detected in the lungs.These results unveil the potential disruption of hematopoietic homeostasis during inhalation of the two MOFs,which provided in vivo biological effect data for further evaluation of the biosafety of MOFs for future medical applications. 展开更多
关键词 Metal-organic frameworks Lungs Flow cytometry HEMATOPOIESIS
原文传递
Comprehensive review of synthesis strategies and performance enhancement of metal-organic frameworks and their derivatives for photocatalytic applications
11
作者 Huihua Luo Lianqing Yu +5 位作者 Chong Liu Nannan Chen Kehui Xue Wendi Liu Haifeng Zhu Yaping Zhang 《Journal of Energy Chemistry》 2025年第4期408-439,共32页
Energy conversion and environmental pollution present significant challenges that necessitate the development of materials with optimal characteristics for effective applications in solar energy-driven photocatalysis.... Energy conversion and environmental pollution present significant challenges that necessitate the development of materials with optimal characteristics for effective applications in solar energy-driven photocatalysis.Metal-organic frameworks(MOFs)serve as excellent platforms for the development of various MOF-derived materials,which have garnered extensive attention due to their unique structural features,high crystallinity,large surface areas,diverse morphologies,adjustable dimensions,tunable textural characteristics,and inherent catalytic activity.However,the sluggish charge kinetics and poor stability of MOFs and MOF-derived photocatalysts restrict their photocatalytic activity,thereby limiting their applications in the field of photocatalysis.Consequently,substantial research efforts have been directed toward maximizing the advantages of these intriguing materials while addressing their shortcomings.This review provides a comprehensive summary and analysis of various synthesis strategies of MOFs and their derivatives.Effective modification strategies to enhance the performance of these novel materials are also summarized.This review systematically explores the current advancements in the application of MOFs and their derivatives for photocatalytic water splitting,photocatalytic CO_(2)reduction,and environmental water pollution treatment.Finally,it discusses the challenges and future prospects of MOFs and MOF-derived materials in photocatalytic applications.Researchers should systematically optimize synthetic strategies and functionalize MOFs and their derivatives to enhance their application in energy conversion and environmental pollution control,thereby underscoring their extensive potential.Future research will increasingly concentrate on the intelligent design and functionalization of MOFs to attain superior catalytic performance and tackle the urgent energy and environmental challenges confronting the world. 展开更多
关键词 Metal-organic frameworks DERIVATIVES Energy convention Environmental pollution
在线阅读 下载PDF
Exploring Regulatory Frameworks for Exosome Therapy:Insights and Perspectives
12
作者 Qiushi Li Yuxia Li +6 位作者 Jiaqing Shao Jianhua Sun Lan Hu Xia Yun Chen Liuqing Likun Gong Shuxia Wu 《Health Care Science》 2025年第4期299-309,共11页
Extracellular vesicles(EVs)have emerged as a promising technology for diagnostic and therapeutic applications in clinical settings over the past decade.However,their advancement is hindered by complex technological an... Extracellular vesicles(EVs)have emerged as a promising technology for diagnostic and therapeutic applications in clinical settings over the past decade.However,their advancement is hindered by complex technological and regulatory challenges.This review outlines key considerations in the manufacturing process,quality management,and nonclinical evaluation relevant to EV-based drug development.Furthermore,we summarize and compare technical regulatory requirements across major countries to help clarify the regulatory principles governing EV products.Our analysis reveals an ongoing international debate regarding the regulatory review of EVs.Nevertheless,adopting a risk-based classification framework that categorizes EV products as advanced therapeutic drugs is a rational approach.Critical challenges include the development of standardized production protocols,a clearer understanding of therapeutic mechanisms,and resolving complex regulatory issues. 展开更多
关键词 extracellular vesicle preclinical development regulatory framework
暂未订购
Construction of two-dimensional heterojunctions based on metal-free semiconductor materials and Covalent Organic Frameworks for exceptional solar energy catalysis
13
作者 Haijun Hu Daming Feng +5 位作者 Kailai Zhang Hui Li Hongge Pan Hongwei Huang Xiaodong Sun Tianyi Ma 《Green Energy & Environment》 2025年第10期1981-1989,共9页
Covalent organic frameworks(COFs)are newly developed crystalline substances that are garnering growing interest because of their ultrahigh porosity,crystalline nature,and easy-modified architecture,showing promise in ... Covalent organic frameworks(COFs)are newly developed crystalline substances that are garnering growing interest because of their ultrahigh porosity,crystalline nature,and easy-modified architecture,showing promise in the field of photocatalysis.However,it is difficult for pure COFs materials to achieve excellent photocatalytic hydrogen production due to their severe carrier recombination problems.To mitigate this crucial issue,establishing heterojunction is deemed an effective approach.Nonetheless,many of the metal-containing materials that have been used to construct heterojunctions with COFs own a number of drawbacks,including small specific surface area and rare active sites(for inorganic semiconductor materials),wider bandgaps and higher preparation costs(for MOFs).Therefore,it is necessary to choose metal-free materials that are easy to prepare.Red phosphorus(RP),as a semiconductor material without metal components,with suitable bandgap,moderate redox potential,relatively minimal toxicity,is affordable and readily available.Herein,a range of RP/TpPa-1-COF(RP/TP1C)composites have been successfully prepared through solvothermal method.The two-dimensional structure of the two materials causes strong interactions between the materials,and the construction of heterojunctions effectively inhibits the recombination of photogenic charge carriers.As a consequence,the 9%RP/TP1C composite,with the optimal photocatalytic ability,achieves a photocatalytic H2 evolution rate of 6.93 mmol g^(-1) h^(-1),demonstrating a 10.19-fold increase compared to that of bare RP and a 4.08-fold improvement over that of pure TP1C.This article offers a novel and innovative method for the advancement of efficient COF-based photocatalysts. 展开更多
关键词 Covalent organic frameworks HETEROJUNCTION PHOTOCATALYSIS Hydrogen production
在线阅读 下载PDF
Building metal-thiolate sites and forming heterojunction in Hf-and Zr-based thiol-dense frameworks towards stable integrated photocatalyst for hydrogen evolution
14
作者 Xin-Lou Yang Jieying Hu +4 位作者 Hao Zhong Qia-Chun Lin Zhiqing Lin Lai-Hon Chung Jun He 《Chinese Chemical Letters》 2025年第7期593-597,共5页
Photocatalytic water splitting for hydrogen evolution reaction(HER)has emerged as one of the most promising approaches for solar energy utilization.Porous easily functionalized metal-organic framework(MOF)represents a... Photocatalytic water splitting for hydrogen evolution reaction(HER)has emerged as one of the most promising approaches for solar energy utilization.Porous easily functionalized metal-organic framework(MOF)represents a rising crystalline material for photocatalytic application.Yet,most MOFs still face challenges like chemical instability in solution media,no photosensitization,and ambiguous active sites.Herein,thiol-dense Hf-or Zr-based porous frameworks(Hf-,Zr-TBAPy-8SH)were prepared as platforms for facile construction of HER active sites by anchoring transition metal(TM)ions as well as forming heterojunction with nanoscale semiconductor(CdS).The highest HER rate of 8.15mmol g^(-1) h^(-1) by Co(Ⅱ)-loaded Hf-based composite highlight(1)[S^(-)-Co]motifs as competent HER site,(2)match heterojunction outweighing traditional photosensitizer-mediated HER,(3)regulating electron density of metal-oxo cluster as a way to harness HER activity.This study firstly demonstrates synergy of Hf-oxo clusters,thiol functionalities and heterojunction as an easy yet controllable strategy to form integrated photocatalyst. 展开更多
关键词 Metal-organic frameworks THIOLS Metal-thiolate Photocatalytic hydrogen production HETEROJUNCTION
原文传递
Enhancing the crystallinity of covalent organic frameworks to achieve improved photocatalytic hydrogen peroxide production under ambient conditions
15
作者 Chongsheng Zhou Le Tao +3 位作者 Jia Gao Jingcun Dong Qingqing Zhu Chunyang Liao 《Journal of Environmental Sciences》 2025年第7期172-181,共10页
Photocatalytic production of hydrogen peroxide(H_(2)O_(2))presents a promising strategy for environmental remediation and energy production.However,achieving clean and efficient H_(2)O_(2) production under ambient con... Photocatalytic production of hydrogen peroxide(H_(2)O_(2))presents a promising strategy for environmental remediation and energy production.However,achieving clean and efficient H_(2)O_(2) production under ambient conditions without organic sacrificial agents remains challenging.Enhancing the low crystallinity of covalent organic frameworks(COFs)can promote the separation and transmission of photo-generated carriers,thereby boosting their photocatalytic performance.Herein,we introduce a novel synthetic approach by substituting traditional acetic acid catalysts with organic base catalysts to enhance the crystallinity of β-ketoenamine-linked COF,TpBD-COF.Compared to TpBD-COF-A synthesized using acetic acid catalysts,TpBD-COF-B,synthesized with organic base catalysts,exhibited advancements including increased absorption intensity in the visible spectrum,reduced photoluminescence intensity,enhanced photo-generated carrier separation performance,and a 2.1-fold increase in photocatalytic H_(2)O_(2) production.Under visible light irradiation,TpBDCOF-B achieved a photocatalytic H_(2)O_(2) production rate of 533μmol/h/g using only air and water,without the need for organic sacrificial agents.Furthermore,TpBD-COF-B also exhibited good performance in long-term catalytic production experiments,tests with actual water bodies,and cyclic usage experiments.This study offers a strategy for enhancing the crystallinity of COFs to improve their photocatalytic activity,with promising applications in clean energy production and environmental remediation. 展开更多
关键词 Covalent organic framework PHOTOCATALYSIS CRYSTALLINITY Hydrogen peroxide production
原文传递
2D and 3D phthalocyanine covalent organic frameworks for electrocatalytic carbon dioxide reduction
16
作者 Qi Zhang Bin Han +3 位作者 Yucheng Jin Mingrun Li Enhui Zhang Jianzhuang Jiang 《Chinese Chemical Letters》 2025年第9期659-663,共5页
Dimensionality has great influence on the photo/electro-catalysts properties of covalent organic frameworks(COFs) because of the different electronic and porous structures.However,very rare attention has been paid on ... Dimensionality has great influence on the photo/electro-catalysts properties of covalent organic frameworks(COFs) because of the different electronic and porous structures.However,very rare attention has been paid on the dimensionality and function correlations of COF materials.In the present work,one new two-dimensional phthalocyanine COF,namely 2D-NiPc-COF,and one new three-dimensional phthalocyanine COF,namely 3D-NiPc-COF,were fabricated according to the imide reaction between tetraanhydrides of 2,3,9,10,16,17,23,24-octacarboxyphthalocyaninato nickel(Ⅱ) with [2,2-bipyridine]-5,5-diamine and tetrakis(4-aminophenyl) methane,respectively.The crystalline structures of both COFs are verified by the powder X-ray diffraction analysis,computational simulation,and high resolution transmission electron microscopy measurement.Notably,3D-NiPc-COF with dispersed conjugated modules has high utilization efficiency of NiPc electroactive sites of 26.8%,almost two times higher than the in-plane stacking2D-NiPc-COF measured by electrochemical measurement,in turn resulting in its superior electrocatalytic performance with high CO_(2)-to-CO Faradaic efficiency over 90% in a wide potential window,a large partial CO current density of-13.97 mA/cm^(2) at-0.9 V(vs.reversible hydrogen electrode) to 2D-NiPc-COF.Moreover,3D-NiPc-COF has higher turnover number and turnover frequency of 5741.6 and 0.18 s^(-1) at-0.8 V during 8 h lasting measurement.The present work provides an example for the investigation on the correlation between dimensionality and electrochemical properties of 2D and 3D phthalocyanine COFs. 展开更多
关键词 PHTHALOCYANINE Dimensionality Covalent organic framework ELECTROCATALYSIS Carbon dioxide reduction
原文传递
Regulating local electron transfer environment of covalent triazine frameworks through F,N co-modification towards optimized oxygen reduction reaction
17
作者 Quanyou Guo Yue Yang +6 位作者 Tingting Hu Hongqi Chu Lijun Liao Xuepeng Wang Zhenzi Li Liping Guo Wei Zhou 《Chinese Chemical Letters》 2025年第1期344-348,共5页
The high conductivity of electrocatalyst can eliminate the Schottky energy barrier at the interface of heterogeneous phases during an electrocatalytic reaction and accelerate the rapid electron transfer to the catalyt... The high conductivity of electrocatalyst can eliminate the Schottky energy barrier at the interface of heterogeneous phases during an electrocatalytic reaction and accelerate the rapid electron transfer to the catalytic active center.Therefore,the electronic conductivity is a vital parameter for oxygen reduction reaction(ORR).Covalent triazine frameworks(CTFs)have shown great potential application as electrocatalysts in ORR with a merit of the diverse building blocks.However,the intrinsic low conductivity and high impedance of CTFs could be significant setbacks in electrocatalytic application.Herein,CTFs were constructed by introducing F and N co-modification for efficient 2e^(-)ORR.Compared with the pristine CTF,the co-presence of F,N could increase the conductivity obviously by 1000-fold.As a result,F-N-CTF exhibits enhanced catalytic performance of H_(2)O_(2)generation and selectivity towards reaction pathways.This work reveals the importance of conductivity optimization for CTFs and provides guidance for designing high conductivity non-metallic organic semiconductor catalysts for 2e^(-)ORR. 展开更多
关键词 Covalent triazine frameworks CONDUCTIVITY Co-modification ELECTROCATALYSIS Oxygen reduction reaction
原文传递
Superb adsorption capacity of ferrocene-based covalent organic frameworks towards Congo red with high-pH resistance
18
作者 Shenglin Wang Qianqian Yan +3 位作者 Jiaxin Yang Hui Hu Songtao Xiao Yanan Gao 《Green Energy & Environment》 2025年第6期1235-1246,共12页
Porous materials are excellent adsorbents for the removal of organic dyes from sewage and play a significant role in environmental restoration.Herein,two ferrocene(Fc)-based covalent organic frameworks(Fc-COFs),namely... Porous materials are excellent adsorbents for the removal of organic dyes from sewage and play a significant role in environmental restoration.Herein,two ferrocene(Fc)-based covalent organic frameworks(Fc-COFs),namely FcTF-COF and FcBD-COF,are successfully synthesized for the first time through a solvothermal method,and the obtained Fc-COFs powders are used to adsorb Congo red(CR)from water.The results show that both FcTF-COF and FcBD-COF have superb adsorption performance towards CR with ultrahigh adsorption capability of 1672.2 mg g−1 and 1983.7 mg g−1 at pH=4.0,respectively,outperforming the majority of the reported solid porous adsorbents.The maximum adsorption of both Fc-COFs agrees with the Sips adsorption isothermal model,indicating that their adsorption was dominated by heterogeneous adsorption.The Coulombic interactions,hydrogen bonding,π-πinteractions and ion-dipolar interactions should all contribute to their ultrahigh CR adsorption capability and high-pH resistance performance regardless of the pH in the range of 4-9.In addition,after five cycles,both COFs still remain their exceptional high CR adsorption capabilities.This study offers a prospective organic porous adsorbent with promising applications for organic dye removal in sewage processing. 展开更多
关键词 Covalent organic frameworks FERROCENE ADSORPTION Congo red Sewage processing
在线阅读 下载PDF
Facets-controllable synthesis of metal-organic frameworks via one supersaturation strategy to insight intrinsic facets effect
19
作者 Lifang Liu Yejun Xiao +2 位作者 Xiangyang Guo Shengye Jin Fuxiang Zhang 《Chinese Journal of Catalysis》 2025年第6期153-158,共6页
The facets effect on the catalytic properties of inorganic compounds and metal-organic frameworks(MOFs)has been widely demonstrated,but the intrinsic facets effect free of interference of capping agents has not been d... The facets effect on the catalytic properties of inorganic compounds and metal-organic frameworks(MOFs)has been widely demonstrated,but the intrinsic facets effect free of interference of capping agents has not been discussed.Here we give a proof-of-concept illustration on the intrinsic facets effect by employing the popularly investigated NH2-MIL-125(Ti)MOFs with{001},{111}and{100}facets controllably exposed as model photocatalysts,which were synthesized via a simple supersaturation strategy free of any capping agents.Compared to conventional synthetic routes with capping agents employed,the NH2-MIL-125(Ti)MOFs obtained in this work exhibit remarkably different physical and chemical properties such as surface wettability,charge separation as well as trend of facets effect on photocatalytic water splitting performance.The main reason has been unraveled to originate from unavoidable residue/influence of capping agents during the conventional facets-controlled synthetic routes leading to changed local surface structural environment as well as distinct charge separation property.Our results demonstrate the importance and feasibility of facets-controllable synthesis free of capping agents in getting insight into the intrinsic facets effect of MOFs-related materials. 展开更多
关键词 Metal-organic framework Facets-controllable synthesis SUPERSATURATION Intrinsic facets effect Photocatalyst
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部