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Strong and tough chitin hydrogel constructed by dehydration and rehydration strategy

Nano Research 2024年第9期17卷 8192-8199页

作者： Rui-Rui Liu Li-Bo Mao Shu-Hong Yu Division of Nanomaterials and chemistry Hefei National Research Center for Physical Sciences at the MicroscaleDepartment of ChemistryInstitute of Biomimetic Materials and ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsUniversity of Science and Technology of ChinaHefei 230026China Institute of Innovative Materials Department of Materials Science and EngineeringDepartment of ChemistrySouthern University of Science and TechnologyShenzhen 518055China

As a renewable,biocompatible,biodegradable soft material,chitin hydrogels have better advantages in stability,antibacterial activity,antifouling,cost,immunogenicity,and so on than most polymer ***,compared with other widely used polymer hydrogels with high strength and toughness,the practical applications of chitin-based hydrogels have been limited by their weak mechanical properties,such as cartilage repair and meniscus ***,we present the design and fabrication of chitin hydrogels with excellent mechanical strength and toughness by a dehydration and rehydration *** sequential dehydration and rehydration processes,the crystalline domains in the chitin hydrogels can be properly *** optimized crystallinity,the elastic modulus of the chitin hydrogels exceeds all previously reported values,and the fracture toughness is even comparable to some synthetic polymer hydrogels,while maintaining a high-water-content of about 80 wt.%.At the same water content,the mechanical properties of the chitin hydrogels are positively correlated with the hydrogel crystallinity,which proves that the change of mechanical properties of hydrogels is not simply dependent on weight *** hydrogels can be further strengthened by incorporating other biopolymers that are intrinsically weak,which makes the hydrogels promising for applications in fields such as cartilage repair and meniscus ***,the hydrogels enable loading and release of water-soluble and poorly water-soluble *** highly extendable strengthening and toughening strategy of chitin and chitin-based biopolymer hydrogels paves the way for their widely applications.

关键词： chitin hydrogel crystallinity rehydration chemical transformation strong and tough

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Facile synthesis of transition metal complexes with five coplanar metal-carbon σ-bonds

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National science Review 2024年第4期11卷 11-12页

作者： Guocheng Jia department of chemistry Hong Kong University of Science and Technology

Carbon is one of the most important elements in chemistry, forming a vast number of organic compounds. It can also form a variety of organometallic compounds with a metal–carbon bond. Metal alkyl, carbene and carbyne complexes are classical examples of organometallic compounds. A particularly interesting class of organometallic compounds are all-carbon metallacycles formed by combination of a metal and a hydrocarbon chain serving as a chelating agent with only carbon atoms as the donor atoms. Many interesting monocyclic metallacycles made of a chelating bidentate hydrocarbon chain are known, for example, metallacyclobutadienes, metallacyclopentadienes and metallabenzenes[1].

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An electron-transfer[Fe_(2)Co_(2)]square complex exhibiting unprecedented wide room-temperature hysteresis

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science China chemistry 2024年第4期67卷 1198-1207页

作者： Xin-Hua Zhao Yi-Fei Deng Jia-Tao Chen Jiong Yang Yuan-Zhu Zhang department of chemistry Southern University of Science and Technology(SUSTech)Shenzhen 518055China

Switchable molecules with magnetic bistability that can function at standard conditions are highly desirable from the perspective of practical *** the last decade,significant progress has been made in modulating thermally induced electrontransfer-coupled spin transition(ETCST)events between diamagnetic{Fe_(LS)^(Ⅱ)(μ-CN)Co_(LS)^(Ⅲ)}and paramagnetic{Fe_(LS)^(Ⅲ)(μ-CN)-Co_(HS)^(Ⅱ)}electron configurations(named LS and HS,respectively,for short)within the Fe/Co mixed-valence cyanometallate ***,we prepared a novel[Fe_(2)Co_(2)]square complex[(pzTp)Fe(CN)_(3)Co(bnbpen)]_(2)[NO_(3)]_(2)·4CH_(3)OH·2.5H_(2)O(1·Solv)and its desolvated phase[(pzTp)Fe(CN)_(3)Co(bnbpen)]_(2)[NO_(3)]_(2)(1),obtained via single-crystal-to-single-crystal(SCSC)*** 1·Solv remaining in the diamagnetic state below room temperature exhibits an irreversible ETCST behavior accompanied by desolvation upon ***,complex 1 displays an unprecedented rate-dependent ETCST behaviour involving with two diamagnetic LS states(a dynamically favoured LS1 state and a thermodynamically favoured LS2state),between which a net one-way transition from LS1 to LS2 is accessible likely via a structural phase transition(SPT)above255 ***,two well separated transition channels(HS?LS1 at around 255 K and HS←→LS2 in the temperature range of 317-350 K)are achieved according to either fast(>20 K/min)or slow rate(<1 K/min),*** a moderate rate of 3 K/min,complex 1 shows a wide hysteresis of 66 K centered at 328 K,the largest yet reported for discrete Fe/Co cyanometallate *** 1 represents the first ETCST example coupled with dynamic SPT,providing a new strategy for manipulating bistability within this fascinating cyanometallate family.

关键词： switchable molecules cyanometallate complexes electron transfer hysteresis structural phase transition

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Converting an O-vacancy-rich oxide into a multifunctional separator modifier for long-lifespan lithium metal batteries

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Journal of Energy chemistry 2024年第10期97卷 371-378页

作者： Juntao Si Xiaoying Li Yixuan Li Kuo Cao Yiran Zhu Chunhua Chen CAS Key Laboratory of Precision and Intelligent chemistry Department of Materials Science and Engineering University of Science and Technology of China

The lithium metal anode is hailed as the desired "holy grail" for the forthcoming generation of highenergy-density batteries,given its astounding theoretical capacity and low ***,the formation and growth of dendrites seriously compromise battery life and ***,an yttriastabilized bismuth oxide（YSB） layer is fabricated on the polypropylene（PP） separator,where YSB reacts with Li anode in-situ in the cell to form a multi-component composite interlayer consisting of Li3Bi,Li2O,and *** interlayer can function not only as a redistributor to regulate Li+distribution but also as an anion adsorber to increase the Li+transference number from 0.37 to 0.79 for suppressing dendrite nucleation and ***,compared with the cell with a baseline separator,those with modified separators exhibit prolonged lifespan in both Li/Li symmetrical cells and Li/Cu ***,the full cells coupled with ultrahigh-loading LiFePO4display an excellent cycling performance of 1700 cycles with a high capacity retention of ～80% at 1 C,exhibiting great potential for practical *** work provides a feasible and effective new strategy for separator modification towards building a much-anticipated dendrite-free Li anode and realizing long-lifespan lithium metal batteries.

关键词： Conversion-alloying reaction Dendrite-free Lithium metal battery Multifunctional interlayer Separator

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Competitive intermetallics formation in Pd-Zn-Cd system via seeded growth from ultra-thin Pd nanosheets for electrocatalytic ethanol oxidation reaction

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Nano Research 2024年第9期17卷 8552-8559页

作者： Donghao Zhang Lianxi Si Qianqian Ren Xintong Yan Shi Hu department of chemistry School of ScienceTianjin Key Laboratory of Molecular Optoelectronic ScienceTianjin UniversityTianjin 300072China

Pd-based catalysts exhibit higher catalytic activity and durability in many electrochemical ***,the electrochemical performance can be further enhanced by fine-tune of the alloy *** binary alloys have been fully studied,the multicomponent alloys are far beyond understanding,which leaves cocktail effect a compromised explanation for the high-entropy *** Pd nanosheet-seeded growth was used to synthesize a Pd-Zn-Cd ternary alloy by accurately controlling the Pd-Zn-Cd molar ratio through adjusting the amount of introduced Cd *** analysis of the crystal phase structure of PdCdZnx and PdZn_(x)Cd_(1-x),the competitive relationship of Zn and Cd in the alloying process with Pd was unveiled:Pd1Cd1 intermetallics(IMC)is thermodynamically favored over Pd_(1)Zn_(1)IMC in the ternary ***,the increased structure stability of PdCd over PdZn does not bring about increased durability in the catalytic ethanol oxidation *** morphology selection of Pd seeds is also crucial for the study,as Pd cubes,Pd tetrahedrons,and Pd octahedrons do not form PdZn in the same *** successful alloying through the seeded growth depends on the maximum diffusion depth of foreign atoms into the seed.

关键词： PdZn alloy seed growth method ethanol oxidation reaction composition control ternary alloying

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Optoelectronic and thermoelectric properties of spinel chalcogenides HgLa2X4（X=S and Se）:A first-principles study

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Journal of Rare Earths 2024年第10期42卷 1927-1936页

作者： Aparna Dixit Inas A.Ahmed Jisha Annie Abraham Zeinhom M.El-Bahy Mumtaz Manzoor Sajad Ahmad Dar Ramesh Sharma department of Basic science and Humanities Pranveer Singh Institute of Technology department of chemistry Faculty of ScienceKing Khalid University department of Physics National Defence Academy department of chemistry Faculty of ScienceAl-Azhar University Institute of Physics Slovak Academy of Sciences department of Physics Motilal Vigyan Mahavidyalya College department of Applied science Feroze Gandhi Institute of Engineering and Technology

We investigated spinel chalcogenides HgLa2（S/Se）4by using density function theory,and scrutinized the structural,optical,electrical,mechanical and thermoelectric transport characteristics of HgLa2（S/Se）4spinel *** enthalpy of formation,energy of cohesion,and energy volume optimum plots were used to obtain the stability as well as the perfect ground state of these *** ductility of these materials was the best illustrated with the help of Poisson's and Pugh's *** band gap results were obtained using Trans and Blaha modified Becke-Johanson potential（TB-mBJ）.Both the materials present semi-conducting nature with direct band gap equal to 1.449 and 0.892 eV respectively for HgLa2S4and *** were also made for optical characteristics with the values of dielectric function,absorption coefficient,optical conductivity,reflectivity,and refractive *** to the findings,both of these materials are suitable for infrared optoelectronic *** materials were found to have promising optoelectronic and thermoelectric applications after their optical properties and transport aspects were *** tiny levels of temperature conductivities,substantial am ounts of power conductivities,the figure of merit（more than unity）,as well as Seebecs coefficients all point to the potential use of both the materials in thermoelectric power generators.

关键词： Density functional theory Direct band gap Optoelectronic Power factor Semiconductors Thermoelectric

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Exfoliation,functionalization and antibacterial activity of transition metal dichalcogenides

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Tungsten 2024年第1期6卷 1-16页

作者： Avijit Mondal Mrinmoy De department of Organic chemistry Indian Institute of ScienceBengaluru 560012India

Due to the growing resistance of available drugs to bacterial infection and the slow development of antibiotics,there is a continuous need to design and develop new antibacterial *** interest to develop transition metal dichalcogenides(TMDs)based antibacterial agents has significantly increased in recent *** research interest is driven by their interesting properties such as metallic and semiconducting nature of different phases,electronic confinement,large surface to volume ratio,the possibility of surface functionalization,and their potential application as a material in biomedical *** synthetic strategies have been developed to synthesize monolayered TMDs and their functionalization with different bioactive *** have given a lot of effort to establish the structure-activity correlation between different TMDs and their antibacterial ***,we have reviewed various exfoliation strategies for TMDs,different methods for their functionalization,and the antibacterial activity of different TMDs.

关键词： Transition metal dichalcogenides(TMD) Functionalization Antibacterial activity Antibacterial mechanism

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Remarkable N_(2)-selectivity enhancement of NH_(3)-SCR over HPMo modified MnCo-BTC@SiO_(2) catalyst

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Journal of Environmental sciences 2024年第4期138卷 482-495页

作者： Songjin Ko Xiaolong Tang Fengyu Gao Honghong Yi Hengheng Liu Ning Luo department of Environmental science and Engineering University of Science and Technology BeijingBeijing 100083China department of chemistry Pyongyang University of ArchitecturePyongyangDPR of Korea

In this work,the phosphomolybdate(HPMo)modification strategy was applied to improve the N_(2) selectivity of Mn Co-BTC@SiO_(2)catalyst for the selective catalytic reduction of NO_(x),and further,the mechanism of HPMo modification on enhanced catalytic performance was *** Mn Co-BTC@SiO_(2-x) catalysts with different HPMo concentrations,Mn CoBTC@SiO_(2)-0.75 catalyst exhibited not only the highest NH_(3)-SCR performance(95% at 200-300℃)but also the best N_(2)selectivity(exceed 80% at 100-300℃)due to the appropriate redox capacity,greater surface acidity.X-ray photoelectron spectrometer(XPS)and temperature programmed reduction of H_(2)(H_(2)-TPR)results showed that the modification with HPMo reduced the oxidation-reduction performance of the catalyst due to electron transfer from Mo^(5+)to Mn^(4+)/Mn^(3+)and prevent the excessive oxidation of ammonia adsorption ***_(3)temperature-programmed desorption of(NH_(3)-TPD)results showed that the modification with HPMo could significantly improve the surface acidity and NH_(3)adsorption,which enhance the catalytic activity and N_(2)***-situ diffused reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS)revealed that modification with HPMo increased significantly the amount of adsorbed NH_(3)species on the Bronsted acid site and C_(B)/C_(L),it suppressed the production of N_(2)O by inhibiting the production of NH species,the deep dehydrogenation of ammonia adsorption *** study provided a simple design strategy for the catalyst to improve the low-temperature catalytic performance and N_(2)selectivity.

关键词： Metal organic framework(MOF) MnCo-BTC@SiO_(2) NH_(3)-SCR HPMo N_(2)selectivity

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

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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 *** 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 *** 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 *** 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 ***,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 *** 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

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Fe3O4/Fe/FeS Tri-Heterojunction Node Spawning N-Carbon Nanotube Scaffold Structure for High-Performance Sodium-Ion Battery

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Energy & Environmental Materials 2024年第4期7卷 143-152页

作者： Yuan Liu Qing Lin Xiaocui Chen Xufeng Meng Baoxiu Hou Haiyan Liu Shuaihua Zhang Ningzhao Shang Zheng Wang Chaoyue Zhang Jianjun Song Xiaoxian Zhao department of chemistry College of Science Hebei Agricultural University College of chemistry and Chemical Engineering Qingdao University College of Physics Qingdao University

The Fe-based anode of sodium-ion batteries attracts much attention due to the abundant source,low-cost,and high specific ***,the low electron and ion transfer rate,poor structural stability,and shuttle effect of NaS2intermediate restrain its further ***,the Fe3O4/Fe/FeS tri-heterojunction node spawned N-carbon nanotube scaffold structure（FHNCS） was designed using the modified MIL-88B（Fe） as a template followed by catalytic growth and sulfidation process.

关键词： anode core-shell heterojunction hollow structure sodium ion batteries

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