检索结果-南通市图书馆

Chinese Chemical Letters 2024年第2期35卷 374-379页

作者： Yonghui Sun Linnan Jiang Yong Chen Yu Liu College of Chemistry State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin 300071China

The construction of hydrogels with good mechanical properties and phosphorescent properties is full of challenges.Herein,we report a supramolecular phosphorescent hydrogel with long lifetime,high tensile strength and self-healing property,which can be easily constructed through in-situ thermalinitiated polymerization of isocyanatoethyl acrylate-modifiedβ-cyclodextrin(β-CD-DA)and acrylatemodified adamantane(Ad-DA),acrylic acid(AA),followed by the non-covalent association with carbon dots(CNDs).The lifetime of phosphorescent hydrogel can reach 1261 ms at room temperature,and the quantum yield is 11%.Importantly,through the efficient triplet to singlet Förster resonance energy transfer(TS-FRET),the phosphorescent hydrogel shows the good phosphorescence energy transfer property for organic dyes Rhodamine B and Eosin Y with the delayed fluorescence lifetime up to 730 ms and 585 ms as well as the energy transfer efficiency(Φ_(ET))up to 99.9%and 99.3%,respectively.Moreover,owing to the host-guest interactions betweenβ-CD-DA and Ad-DA,the three-dimensional cross-linked network phosphorescent hydrogel can be easily stretched to 18 times of its original length,and can achieve self-healing of the cut surfaces within 30 min.These results will expand the scope of phosphorescent materials and provide new ideas and opportunities for materials science.

关键词： Room temperature phosphorescence Hydrogel Phosphorescence energy transfer Cyclodextrin Supramolecular interaction

Performance enhancement and active sites identification of Cu-Cd bimetallic oxide derived catalysts for electrochemical CO_(2) reduction

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第4期91卷 50-58页

作者： Cai Wang Xin Hu Bairong Chen Houan Ren Xiaoyu Wang Yilin Zhang Xinyu Chen Yuping Liu Qingxin Guan Wei Li state key laboratory of Elemento-organic Chemistry Key Laboratory of Adv.Energy Mater.Chemistry(Ministry of Education)College of ChemistryNankai UniversityTianjin 300071China

The development of earth-abundant electrocatalysts with high performance for electrochemical CO_(2)reduction(ECR)is of great significance.Cu-based catalysts have been widely investigated for ECR due to their unique ability to generate various carbonaceous products,but directing selectivity toward one certain product and identifying the real active sites during ECR are still full of challenge.Here,after the incorporation of CdO into CuO,the Cu_(0.5)Cd_(0.5)-O catalyst achieves a 10.3-fold enhancement for CO selectivity in comparison with CuO,and a CO faradic efficiency nearly 90%with a current density around20 mA cm^(-2)could maintain at least 60 h.Interestingly,a wide CO/H_(2)ratio(0.07-10)is reached on Cu_(x)Cd_(1-x)-O catalysts by varying the Cu/Cd ratio,demonstrating the potential of syngas production using such catalysts.The results of ex situ XRD,XPS,and in situ Raman reveal that the real active sites of Cu_(0.5)Cd_(0.5)-O catalysts for CO production during ECR reaction are the reconstructed mixed phases of CuCd alloy and CdCO_(3).In situ FTIR and theoretical calculations further implicate the presence of Cd related species promotes the CO desorption and inhibits the H_(2)evolution,thus leading to an enhanced CO generation.

关键词： CO_(2)reduction Cu-Cd bimetallic Real active sites CO production

Impact of Polymer Matrix on Polymer Mechanochromism from Excited state Intramolecular Proton Transfer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第6期42卷 611-616页

作者： Yu Wu Xin Cheng Huan Hu Shui Hu Zhimin Ma Zhiyong Ma Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing State Key Laboratory of Organic-Inorganic CompositesCollege of Chemical EngineeringBeijing University of Chemical TechnologyBeijing100029 China Center of Advanced Elastomer Materials College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing100029 China College of Engineering Peking UniversityBeijing100871 China

Mechanochromic polymers based on non-covalent changes have attracted much attention recently.Herein,we report the impact of inter/intramolecular hydrogen bonds on polymer mechanochromism from the excited state intramolecular proton transfer (ESIPT) process.PhMz-NH2-OH and PhMz=2A are designed and obtained by simple and high-yield synthesis,and are connected into polyurethane and poly(methyl acrylate-co-2-ethylhexyl acrylate),respectively.In the initial state,the PhMz-NH2-OH@PU sample shows blue fluorescence from the excited enol form (E*) excitons,owing to intermolecular hydrogen bonds that interrupt the ESIPT reactions but the PhMz=2A@PMA-2-EA sample expresses cyan fluorescence belonging to the excited keto form (K*) emission,implying that the intramolecular hydrogen bonds matter.Furthermore,under stretching,external force can tune the emission of the PhMz=2A@PMA-2-EA sample from K* to E* state.Though external force can putatively still promote a bond rotation,ESIPT reactions remain equivalently interrupted in both the relaxed and stressed states in a hydrogen-bond donating environment.DFT calculation confirms the force-induced increase in dihedral angle for the transition of ESIPT-on/off.Thus,PhMz-NH2-OH@PU and PhMz=2A@PMA-2-EA showed disparate initial ESIPT states and further different responses/sensitivity to force.This study reports a novel and efficient strategy for enriching mechanochromic investigation and extending the applications of ESIPT reactions.

关键词： Polymer mechanochromism Excited state intramolecular proton transfer Hydrogen bonding Supramolecular chemistry Elastomers

Efficient construction of calcium fluoride nanoaggregates for enhanced water vapor adsorption

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第6期89卷 191-197页

作者： Dan-Lei Yang Jing Cao Rong-Kun Liu Jie-Xin Wang School of Life Sciences and Chemical Engineering Jiangsu Second Normal UniversityNanjing210013China state key laboratory of organic-inorganic composites Beijing University of Chemical TechnologyBeijing 100029China Research Center of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing100029China Petrochemical Research Institute PetroChinaBeijing102206China

Calcium fluoride(CaF_(2))is an ideal adsorbent for the dehydration of gaseous hydrogen fluoride(HF)containing water vapor.In this work,a novel CaF_(2)absorbent,spherical CaF_(2)nanoaggregates(NAs)with a closely packed structure,was proposed and efficiently fabricated by spray drying technology.As the building blocks of CaF_(2)NAs,the CaF_(2)nanoparticles(NPs)were prepared by the addition of excess calcium ions(Ca^(2+))or fluorine ions(F−)in the synthesis.The results indicated that the CaF_(2)NPs synthesized by excess Ca^(2+)and the corresponding NAs exhibited much better water vapor adsorption properties than their counterparts by excess F−,owing to higher zeta potentials.More importantly,whether excess Ca^(2+)or F^(−),CaF_(2)NAs had further enhanced water vapor adsorption capacity compared to primary CaF_(2)NPs,possibly owing to their unique nano-micro secondary structures and higher surface areas.This work has great potential in the development of high-performance absorbents for separating moisture from corrosive gas HF.

关键词： CaF_(2)nanoaggregates Water vapor adsorption Spray drying

Rapid and controllable in-situ self-assembly of main-group metal nanofilms for highly efficient CO_(2)electroreduction to liquid fuel in flow cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第6期17卷 5718-5725页

作者： Miao Wang Huaizhu Wang Yaoda Wang Junchuan Liang Mengfei Zhu Jiarui Li Zuoxiu Tie Zhong Jin state key laboratory of Coordination Chemistry MOE Key Laboratory of Mesoscopic ChemistryMOE Key Laboratory of High Performance Polymer Materials and TechnologyJiangsu Key Laboratory of Advanced Organic MaterialsTianchang New Materials and Energy Technology Researc

The electrocatalytic reduction of CO_(2)is a promising pathway to generate renewable fuels and chemicals.However,its advancement is impeded by the absence of electrocatalysts with both high selectivity and stability.Here,we present a scalable in-situ thermal evaporation technique for synthesizing series of Bi,In,and Sn nanofilms on carbon felt(CF)substrates with a high-aspect-ratio structure.The resulting main-group metal nanofilms exhibit a homogeneously distributed and highly exposed catalyst surface with ample active sites,thereby promoting mass transport and ad-/desorption of reaction intermediates.Benefiting from the unique fractal morphology,the Bi nanofilms deposited on CF exhibit optimal catalytic activities for CO_(2)electroreduction among the designed metal nanofilms electrodes,with the highest Faradaic efficiency of 96.9%for formate production at−1.3 V vs.reversible hydrogen electrode(RHE)in H-cell.Under an industrially relevant current density of 221.4 mA·cm−2 in flow cells,the Bi nanofilms retain a high Faradaic efficiency of 81.7%at−1.1 V(vs.RHE)and a good long-term stability for formate production.Furthermore,a techno-economic analysis(TEA)model shows the potential commercial viability of electrocatalytic CO_(2)conversion into formate using the Bi nanofilms catalyst.Our results offer a green and convenient approach for in-situ fabrication of stable and inexpensive thin-film catalysts with a fractal structure applicable to various industrial settings.

关键词： CO_(2)electroreduction non-noble metal nanofilms flow cells efficiency and selectivity techno-economic analysis

Janus Quasi‑Solid Electrolyte Membranes with Asymmetric Porous Structure for High‑Performance Lithium‑Metal Batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第6期16卷 221-232页

作者： Zerui Chen Wei Zhao Qian Liu Yifei Xu Qinghe Wang Jinmin Lin Hao Bin Wu Institute for composites Science Innovation(InCSI)and state key laboratory of Silicon and Advanced Semiconductor Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China

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.

关键词： Metal-organic frameworks Mesoporous silicas Quasi-solid electrolytes Janus structure Lithium-metal battery

The structure-directing role of heterologous seeds in the synthesis of zeolite

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第5期9卷 792-801页

作者： Haoyang Zhang Binyu Wang Wenfu Yan state key laboratory of inorganic Synthesis&Preparative Chemistry College of ChemistryJilin UniversityChangchun130012China

Zeolites have been widely used as catalysts,ion-exchangers,and adsorbents in chemical industries,detergent industry,steel industry,glass industry,ceramic industry,medical and healthﬁeld,and environmentalﬁeld,and recently applied in energy storage.Seed-assisted synthesis is a very effective approach in promoting the crystallization of zeolites.In some cases,the target zeolite cannot be formed in the absence of seed zeolite.In homologous seed-assisted synthesis,the structure of the seed zeolite is the same to that of the target zeolite,while the structure of the seed zeolite is different to that of the target zeolite in the heterologous seed-assisted synthesis.In this review,we brieﬂy summarized the heterologous seed-assisted syntheses of zeolites and analyzed the structure-directing effect of heterologous seeds and surveyed the“common composite building units(CBUs)hypothesis”and the“common secondary building units(SBUs)hypothesis”.However,both hypotheses cannot explain all observations on the heterologous seed-assisted syntheses.Finally,we proposed that the formation of the target zeolite does need nuclei with the structure of target zeolite and the formation of the nuclei of the target zeolite can be promoted by either the undissolved seed crystals with the same CBUs or SBUs to the target zeolite or by the facilitated appropriate distribution of the speciﬁc building units due to the presence of the heterologous seed that does not have any common CBUs and SBUs with the target zeolite.

关键词： Zeolite Heterologous seed Synthesis Structure-directing effect

Linear paired electrolysis of furfural to furoic acid at both anode and cathode in a multiple redox mediated system

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第1期9卷 104-113页

作者： Xinxin Li Linchuan Cong Haibo Lin Fangbing Liu Xiangxue Fu Hai-Chao Xu Nan Lin state key laboratory of inorganic Synthesis and Preparative Chemistry Jilin UniversityChangchun 130012JilinChina state key laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005FujianChina

Implementing a new energy-saving electrochemical synthesis system with high commercial value is a strategy of the sustainable development for upgrading the bulk chemicals preparation technology in the future.Here,we report a multiple redox-mediated linear paired electrolysis system,combining the hydrogen peroxide mediated cathode process with the I2 mediated anode process,and realize the conversion of furfural to furoic acid in both side of the dividedﬂow cell simultaneously.By reasonably controlling the cathode potential,the undesired water splitting reaction and furfural reduction side reactions are avoided.Under the galvanostatic electrolysis,the two-mediated electrode processes have good compatibility,which reduce the energy consumption by about 22%while improving the electronic efﬁciency by about 125%.This system provides a green electrochemical synthesis route with commercial prospects.

关键词： Multiple redox mediated system Linear paired electrolysis Furfural Furoic acid

Cobalt(Ⅲ)hydride HAT mediated enantioselective intramolecular hydroamination access to chiral pyrrolidines

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第6期67卷 2002-2008页

作者： Qi Meng Tao Qin Huanran Miao Ge Zhang Qian Zhang Jilin Province key laboratory of organic Functional Molecular Design&Synthesis Department of ChemistryNortheast Normal UniversityChangchun130024China state key laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai200032China

Enantioenriched pyrrolidines and derivatives are ubiquitous substructures in compounds of importance to medicinal and biological chemistry.Herein,we report an efficient cobalt-catalyzed intramolecular asymmetric hydroamination reaction that produces chiral pyrrolidines with good to excellent yield and enantiocontrol.Compared with previously reported radicalinvolved methodologies for enantioenriched pyrrolidines,these conditions feature two elegant versatilities,enabling(1)the use of cobalt-catalyzed hydrogen atom transfer(HAT)to generate organocobalt intermediates that bring radical reaction to organometallic chemistry,and(2)enantioselective intramolecular C-N bond forging through an S_(N)2-like displacement involving dynamic kinetic resolution(DKR).This approach provides a new alternative and efficient methodology for enantioselective radical-involved C-N bond construction that can be used in the synthesis of both chiral pyrrolidines and homologous nitrogen heterocycles.

关键词： asymmetric catalysis radical hydroamination cobalt catalysis hydrogen atom transfer

Dielectric polymer grafted electrodes enhanced aqueous supercapacitors

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 1525-1534页

作者： Shian Dong Kunming Shi Jie Chen Yingke Zhu Hongfei Li Weihang Gao Zhenli Xu Qinglei Liu Xingyi Huang Shanghai key laboratory of Electrical Insulation and Thermal Aging Department of Polymer Science and EngineeringState Key Laboratory of Metal Matrix CompositesShanghai Jiao Tong UniversityShanghai 200240China School of Mathematical Sciences Institute of Natural Sciences and MOE−LSCShanghai Jiao Tong UniversityShanghai 200240China state key laboratory of Metal Matrix composites Shanghai Jiao Tong UniversityShanghai 200240China

Supercapacitors(SCs)have become increasingly important in electrical energy storage and delivery owing to their high power densities and long lifetimes.Aqueous SCs are promising for large-scale engineering applications because of their low cost and safety.However,the low operating voltage and low energy density of aqueous SCs severely limit their practical applications.In this study,a nanoscale dielectric layer is grafted onto a graphene electrode to achieve both a high operating voltage and enhanced capacitance.Compared with an SC without dielectric grafting,a dielectric-enhanced SC(DESC)shows a higher capacitance by 2200%.The mechanism of the capacitance enhancement can be attributed to three factors:the dielectric polarization,the ions desolvation by the dielectric,and the enhanced quantum capacitance from charge transfer and ion adsorption in the polymer molecules.In addition,a 2.5 V pouch DESC with a 1 M KCl electrolyte is confirmed to cycle up to 50,000 times with a capacitance retention of 87.5%.The DESC presents the optimal electrochemical properties after it is grafted with a 5 nm dielectric layer.This study provides new insights into the design of high-voltage and high-energy-density aqueous SCs.

关键词： supercapacitors dielectric polymer high voltage capacitance enhancement