A mixed-valence polyoxometalate-based 3D inorganic framework cathode material for high-efficiency rechargeable AZIBs

The global trend towards new energy storage systems has stimulated the development of electrochemical energy storage technologies.Among these technologies,rechargeable aqueous zinc-ion batteries(AZIBs)have attracted considerable interest as a potential alternative to lithium-ion batteries(LIBs)due to their affordable cost,environmental compatibility and high safety standards.In this study,a high-quality electrode for AZIBs has been successfully developed using a dehydrated mixed-valence polyoxometalate-based three-dimensional(3D)inorganic framework material known as[H_6Mn_(3)V^Ⅳ_(15)V-^Ⅴ_(4O)_(46)(H_2O)_(12)](3D-MnVO).This innovative 3D-MnVO material is built from the alternate connections of{V_(19)O_(46)}"sphere-shaped"clusters andμ_(2)-{Mn(H_(2)O)_(4)}bridges,where each{V_(19)O_(46)}cluster is surrounded by three pairs of vertically distributed{Mn(H_(2)O)_(4)}units,thus resulting in the 3D interpenetrating grid-like network from the infinite[-{V_(19)O_(46)}-μ_(2)-Mn(H_(2)O)_(4)-{V_(19)O_(46)}]_∞chains in three mutually perpendicular directions.The 3D framework structure of 3D-MnVO possesses abundant oxygen vacancies,spacious and multi-level interconnected channels for ion transport,which facilitates the efficient intercalation/deintercalation of hydrated Zn^(2+)into the pores of the primary structure via the intercalation capacitance mechanism.As a result,the 3D-MnVO electrode exhibits excellent diffusion rates and minimal interfacial resistance.At a current density of 0.1 A·g^(-1),the 3D-MnVO cathode delivers a commendable discharge capacity of170.5 mAh·g^(-1)with 81.6%capacity retention after100 charge/discharge cycles.Furthermore,even at a high current density of 1.0 A·g^(-1),the 3D-MnVO electrode delivers a remarkable reversible capacity of198.9 mAh·g^(-1).Our research results provide valuable insights into the development of advanced polyoxometalate-based 3D inorganic framework electrode materials for high-performance rechargeable AZIBs.

Solvothermal Synthesis,Crystal Structure and Properties of a 3D Organically Amine Templated Lanthanide Sulfate

A new sulfate inorganic framework, {（C2H8N）9[Nds（SO4）12]·2H2O}n （1） templated by organic amine, has been solvothermally synthesized and characterized by TGA, PXRD and single-crystal X-ray diffraction. Compound 1 crystalizes in monoclinic, space group C2/c with a = 20.570（5）, b = 35.815（8）, c = 10.106（2） A, C108H72NgNd5050S12, Mr = 2315.73, V= 6765（3） A3, Z = 4, Dc = 2.274 g·cm-3, μ = 4.253 mm-1, F（000 = 4520, 2.52〈θ〈25°, λ（MoKa） = 0.71073 A, T= 273（2） K, the final R =0.0401, wR = 0.1022 and S = 1.042. X-ray diffraction analysis reveals that complex 1 possesses a 3D inorganic sulfate framework with large 20-membered ring （20 MR） and 10-membered ring （10 MR） channels constructed by two kinds of SBUs. Moreover, the UV-vis and luminescent properties of comolex I were also investigated

Self-assembly of a new 3D platelike ternary-oxo-cluster:An efficient catalyst for the synthesis of pyrazoles

A new metal-oxo-clusters-based inorganic framework[NaCo_(2)Mo_(2)O_(7)(OH)_(3)]_(n)(NaCoMo),named as 3D platelike ternary-oxo-cluster,has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction structure analysis,FT-IR spectroscopy,powder X-ray diffraction(PXRD),scanning electron microscope(SEM),energy-dispersive X-ray spectroscopy(EDS)analyses,X-ray photoelectron spectroscopy(XPS)and thermogravimetric analysis(TGA).Structure analysis reveals that there are no classical building units in NaCoMo,and the asymmetric units of NaCoMo are directly extended into a new platelike 3D structure.Density functional theory calculations(DFT)indicates that the crystal formation process is exothermic and the structure is extremely stable.In addition,the compound presents excellent catalytic activity in the condensation and cyclization reaction of sulfonyl hydrazides and 1,3-diketones to synthesize pyrazoles,and the yield of the desired product is up to 99%.The successful synthesis of NaCoMo represents the discovery of a new kind of non-classical polyoxometalates.