反溶剂法快速合成高效发光二维锡卤钙钛矿材料

铅卤钙钛矿材料由于其优异的光电性质而受到了广泛关注. 但是, 材料中铅的毒性问题极大地阻碍了其大规模应用. 因此, 寻找与铅卤钙钛矿具有相似光电性质的非铅卤化物钙钛矿材料十分重要. 其中, 锡基卤化物钙钛矿被认为是铅基钙钛矿材料最佳的替代材料之一. 本文通过简便的反溶剂方法, 合成了一系列新型二维(RNH₃)₂SnX₄(R为烷基链, X=Br^-, I^-)钙钛矿材料. 研究结果表明, 所合成的材料具有优异的荧光发射性质, 发光量子效率高达98.5%, 比三维ASnX₃[A=Cs⁺, 甲胺(MA⁺), 甲脒(FA⁺)等]型钙钛矿表现出更好的稳定性. 本文所采用的合成方法简单易行, 有利于实现金属卤化物钙钛矿材料的大规模合成及在固态照明器件和显示器件领域的工业应用.     

两种3D微孔Zn-MOF对水溶液中Fe3+、Cr2O72-和丙酮分子的荧光传感(英文)

通过溶剂热法合成了2种三维微孔锌金属有机框架材料,其分子式为[Zn₃(DBA)(OH)(1,10-phen)₂]_n (1)和{[Zn₂(HDBA)(4,4′-bipy)_1.5]·H₂O}_n (2)(H₅DBA=3,5-二(2′,4′-对羧基苯基)苯甲酸;1,10-phen=1,10-菲咯啉;4,4′-bipy=4,4′-联吡啶)。结构分析表明,配合物1为三核锌基金属单元的三维微孔骨架,配合物2为双核锌基的微孔结构。与2相比,配合物1在水中具有较强的发光性能,可作为检测Fe³⁺、Cr₂O₇^2-和丙酮分子的发光传感器,具有较高的选择性和灵敏度。     

磷酸铁锂废料中FePO4·2H2O提取及其杂质形成机理

采用化学共沉淀方法从磷酸铁锂废料中提取FePO₄·2H₂O,并研究了回收过程中杂质形成的机理。在热力学计算基础上绘制了298和363 K时Fe-P-Li-H₂O体系的电势(φ)-pH图,结果表明当pH≤5.0时,Fe(OH)₃相可以自发地转成FePO₄·2H₂O相,从而得到高纯的FePO₄·2H₂O。但实验结果发现当溶液中铁、磷的物质的量之比(n_Fe∶n_P)为1∶1,合成pH为1.5～2.2时得到的FePO₄·2H₂O中存在Fe(OH)₃杂质,这是因为在共沉淀过程中少量Fe³⁺以Fe(OH)₃快速沉淀,而陈化时Fe(OH)₃相转化速率慢,因此FePO₄·2H₂O中含有Fe(OH)₃     

一种用于检测罗红霉素和B4O72-的高稳定性Cd(Ⅱ)配位聚合物(英文)

在溶剂热条件下,成功合成了一种稳定的配位聚合物[Cd₂(L)(bpb)(H₂O)₄]·0.5H₄L (1)(H₄L=1,1′-乙烷基联苯-3,3′,5,5′-四羧酸,bpb=1,4-二(4-吡啶基)苯)。1在不同的有机溶剂和水中表现出优异的稳定性。1可通过荧光猝灭检测水中的罗红霉素(ROX)和B₄O₇^2-,检测限分别为0.21和1.59μmol·L^-1。1可成功用于延河水中ROX和B₄O₇^2-的测定。此外,分析讨论了其传感机理。     

A unique organic-inorganic hybrid FeⅢ–PrⅢ-included 2-germano-20-tungstate and its electrochemical biosensing properties

An organic-inorganic hybrid Fe^Ⅲ–Pr^Ⅲ-included 2-germano-20-tungstate [Pr（H₂O）₈]₂H₂[Fe₄（H₂O）₄（pca）₄Ge₂W₂₀O₇₂]·34H₂O（Hpca=2-pyridinecarboxylic acid）(1) was hydrothermally prepared. Its polyoxoanion comprises one tetra-Fe^Ⅲ incorporated [Fe₄（H₂O）₄（pca）₄Ge₂W₂₀O₇₂]...     

Noncentrosymmetric K2Mn3(SO4)3F2·4H2O and Rb2Mn3(SO4)3F2·2H2O with pseudo-KTP structures

Two fluoride sulfates,K₂Mn₃(SO₄)₃F₂·4H₂O(Ⅰ) and Rb₂Mn₃(SO₄)₃F₂·2H₂O (Ⅱ) are obtained by water solution method.Single-crystal X-ray diffraction analysis indicated that they crystallize in space groups of Cmc2_1.Their structures feature a pseudo-KTP structure consisting of interconnecting[Mn₃(SO₄)3F₂(H₂O)2]_∞ layers,which are further packing along the a axis with alkali metal cations balancing the charges.The structure relationships between the two compounds are discussed.Secondharmonic generation measurements manifest that Ⅰ and Ⅱ have similar second-harmonic generation responses of about 0.2 and 0.25 times that of KH₂PO₄.     

CeO2/γ-Al2O3复合材料制备及其光催化性能研究

以Ce(NO₃)₃·6H₂O及Al(NO₃)₃·9H₂O为原料,NH₄HCO₃为造孔剂,以沉淀法制备了具有介孔结构的CeO₂/γ-Al₂O₃光催化材料。研究了不同NH₄∶Al及Ce∶Al摩尔比等条件下制备CeO₂/γ-Al₂O₃样品的光催化性能。结果表明,所制备CeO₂/γ-Al₂O₃复合材料具有优异的光催化性能,最佳NH₄∶Al及Ce∶Al摩尔比分别为1及0.2,该条件下制备的样品BET比表面积为94.4642 m²·g^-1,孔径为5.8565 nm,对亚甲基蓝(MB)的光催化降解率可达93.59%,动力学常数k为0.0218 m...     

钇(Ⅲ)、铽(Ⅲ)、铒(Ⅲ)对氨基苯甲酸配合物共掺杂二氧化硅的光声光谱研究

合成了Tb(p-ABA)₃·H₂O和Ln(p-ABA)₃·H₂O(p-ABA: 对氨基苯甲酸, Ln: Y或Er)配合物共掺杂的SiO₂样品. 荧光光谱测定结果表明, Y(p-ABA)₃·H₂O的引入增强了样品中Tb³⁺离子的特征发光, 而Er(p-ABA)₃·H₂O的引入使Tb³⁺的发光减弱. 光声光谱结果表明, 与Tb³⁺配合物单掺的样品相比, Tb³⁺和Y³⁺配合物共掺样品的光声强度降低; 而Tb³⁺和Er³⁺配合物共掺的样品则情况相反. 实验测定了共掺杂样品的相对量子发光效率和发光寿命, 从无辐射跃迁和辐射跃迁的角度提出共发光效应可能的机制. 结合对室温下陈化干燥样品的分析发现, 只有经适当的热处理过程才能在SiO₂凝胶中形成具有多核结构的稀土配合物.     

SnO2双层电子传输层对钙钛矿太阳能电池界面电荷传输的影响

为了改善基于SnO₂电子传输层的钙钛矿太阳能电池的界面电荷传输特性和迟滞现象,我们采用低温溶液处理工艺制备了4种不同类型的SnO₂电子传输层用于钙钛矿太阳能电池,包括由SnCl₄·5H₂O溶胶-凝胶层(Cl₄-SnO₂)、SnCl₂·2H₂O溶胶-凝胶层(Cl₂-SnO₂)和SnO₂纳米颗粒层(NP-SnO₂)与SnO₂胶体层(Col-SnO₂)两两相互作用形成的同质结SnO₂双层电子传输层和Col-SnO₂单层电子传输层;并系统研究了不同SnO₂双层电子传输层对器件光电性能和迟滞现象的影响。通过扫描电镜(SEM)、X射线衍射(XRD)、稳态光致发光(PL)、电化学阻抗(EIS)和稳定性测试等表征证实,在Col-SnO...     

A Novel 3D CdⅡ-CP Based on a Bi-functional（N-/O-Sites） Triazole-modified Carboxyl Ligand: Structure,Topology and Photoluminescence

With triazole-modified derivative as link,one new framework[Cd₅(μ₅-HL^2-)₂(μ₄-L^3-)₂（H₂O）₁₀]·2H₂O(1,H₃L=2-（1,2,4-triazol-1-yl）benzene-1,3,5-tricarboxylic acid) has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction,powder X-ray diffraction and elemental analysis.Complex 1exhibits a 3D （3,4,6）-connected net cross-linked by binuclear[Cd₂     

NdCl3-CdCl2-HCl-H2O的相平衡及其固相化合物的研究

测定了四元系NdCl₃-CdCl₂-HCl-H₂O(298. 15 K) 的相平衡溶度数据, 绘制了相应的溶度图. 该四元系是由4个固相区CdCl₂•H₂O(原始盐)、9CdCl₂•NdCl₃•20H₂O、5CdCl₂•NdCl₃•13H₂O、NdCl₃•6H₂O(原始盐)组成的复杂体系. 用X射线粉末衍射及TG-DTG和荧光光谱对9CdCl₂•NdCl₃•20H₂O 和5CdCl₂•NdCl₃•13H₂O进行了研究. 荧光研究表明, 化合物9CdCl₂•NdCl₃•20H₂O具有微弱的荧光强度, 5CdCl₂•NdCl₃•13H₂O的荧光强度则相对大于9CdCl₂•NdCl₃•20H₂O的. 对X射线粉末衍射进行了指标化.     

BaO∙4B2O3∙5H2O纳米材料的制备及其对聚丙烯阻燃性能的热分解动力学方法评价

Borate is considered one of the most important additives for improving the fire-resistance of combustible polymers because of its smoke suppression, low toxicity, and good thermal stability. However, the size of prepared borate is usually in the micrometer range, which makes it difficult to disperse in a polymer matrix, thus hindering its use as fire-retardant material. The preparation and application of borate nanomaterial as flame retardant is considered an effective method. However, the preparation of barium borate nanomaterials as flame retardant has not been reported. In this paper, nanosheets and nanoribbons with different sizes for a new barium borate BaO·4B₂O₃·5H₂O are prepared by hydrothermal method, and characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum (FT-IR), thermogravimetric analysis-differential scanning calorimetry (TG-DSC), and scanning electron microscope (SEM). The flame-retardant properties of polypropylene (PP)/BaO·4B₂O₃·5H₂O composites are investigated by thermogravimetric analysis (TG), differential scanning calorimetry (DSC) thermal analysis methods and limited oxygen index (LOI) method. Considering the near TG mass losses and the near LOI values for PP with 10% prepared BaO·4B₂O₃·5H₂O nanosheet and nanoribbon, their flame-retardant properties need to be further evaluated by non-isothermal decomposition kinetic method. The apparent activation energy for this decomposition reaction was obtained from the slope by plotting ln(β/T_p²) against 1/T_p according to Kissinger's model. With the reduction of TG mass loss, increased heat absorption in DSC under N₂ atmosphere, increased apparent activation energy E_a for the thermal decomposition of PP/BaO·4B₂O₃·5H₂O composite as well as increased LOI value, the flame-retardant performance of prepared BaO·4B₂O₃·5H₂O samples with PP gradually improved from bulk to nanoribbon to nanosheet. This can be attributed to the decrease in the size of BaO·4B₂O₃·5H₂O samples because the smaller sample size leads to improved dispersion and increased contact area with the polymer. The flame-retardant mechanism is discussed by analyzing the after-flame chars of the PP/BaO·4B₂O₃·5H₂O composite in SEM images, which show that the char layer is more compact and continuous for the PP/BaO·4B₂O₃·5H₂O nanosheet composite. The influence of loading BaO·4B₂O₃·5H₂O nanomaterials on the mechanical properties of PP is also tested using a universal material testing machine, in which the PP/BaO·4B₂O₃·5H₂O nanosheet composite has higher tensile strength. The PP/BaO·4B₂O₃·5H₂O nanosheet composite has the best flame-retardant and mechanical properties, which is promising to be developed for the application as flame-retardant material.     

A Unique Layered Cu-formate Hydrate of Cu(HCOO) 2·1/3H2O: Structures,Dehydration, and Thermal and Magnetic Properties

Anew layered Cu-formate hydrate of Cu(HCOO)₂·1/3H₂O is unique in its water content and the strongly waved (4,4) Cu-formate layers held by interlayer weak axial Cu-O_formate bonds and O-H_water···O_formate hydrogen bonds. The crystal is in orthorhombic space group Pbcn, with cell parameters at 80 K:a=7.9777(2) Å, b=7.3656(2) Å, c=21.0317(5) Å(1 Å=10⁻¹ nm), and V=1235.83(5) ų. The Cu²⁺ ions are in the environments of a square pyramid and elongated octahedron, in a ratio of 1/2 within the structure. In the layer, Cu²⁺ ions are connected by anti-anti formates via short basal Cu-O bonds. The structure remains unchanged until the dehydration that produces the layered anhydrous β-Cu(HCOO)₂, and the possible transformation mechanism, supported by diffraction evidence, is the reorganization of the Cu-O_formate bonds across the parent layers after dehydration. The two phases exhibit anisotropic thermal expansion behaviors closely relevant to the transverse thermal vibrations of the constituents. Cu(HCOO)₂·1/3H₂O is a 2-dimensional Heisenberg antiferromagnet, and exhibits a global spin-canted antiferromagnetism with the Néel temperature of 32.1 K. This is not only higher than that of the magnetically denser β-Cu(HCOO)₂, but also the highest among the copper formate frameworks.     

胺和水插层磷酸锰仿生模拟氢键网络用于电催化水氧化

Asymmetric manganese cluster, the active center of photosystem II (PSII) in nature, is hydrogen-bonded to surrounding amino acid residues and water molecules. This phenomenon is of great inspiration significance for developing and studying artificial Mn-based oxygen evolution reaction (OER) catalysts. Herein, we prepared manganese phosphate nanosheets through intercalation of ethylenediamine ions and water molecules ((EDAI)(H₂O)MnPi) using a simple co-precipitation method. (EDAI)(H₂O)MnPi is also hydrogen-bonded to interlayer ethylenediamine ions and water molecules, forming a hydrogen-bonding network. The morphology of the (EDAI)(H₂O)MnPi sample was characterized by scanning electron microscopy (SEM) and transmission electron microscopy. The thickness of (EDAI)(H₂O)MnPi was characterized by atomic force microscopy. The composition and structure of (EDAI)(H₂O)MnPi were characterized by X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy. For control studies, manganese phosphate (EDAI)MnPi and (H₂O)MnPi samples were also synthesized. The structure and morphology of (EDAI)MnPi and (H₂O)MnPi samples were characterized by XRD and SEM. The difference between (EDAI)(H₂O)MnPi, (EDAI)MnPi, and (H₂O)MnPi were further characterized by thermal gravimetric analysis and derivative thermogravimetric analysis. Electrocatalytic properties of the (EDAI)(H₂O)MnPi, (EDAI)MnPi, and (H₂O)MnPi for OER were studied in 0.05 mol∙L⁻¹ pH = 7 phosphate buffered saline solution, through linear sweep voltammetry, electrochemical impedance spectroscopy, and controlled potential electrolysis (CPE) test. The electrochemical surface area (ECSA) analyses of (EDAI)(H₂O)MnPi, (EDAI)MnPi, and (H₂O)MnPi samples were recorded by charging currents in the non-Faradaic potential region at different scan rates. Considering the different ECSAs of different materials, the water oxidation activities of three materials were normalized by ECSA. Compared with counterparts of (EDAI)MnPi (610 mV) and (H₂O)MnPi (580 mV), manganese phosphate nanosheets (EDAI)(H₂O)MnPi exhibited a lower overpotential of 520 mV when driving a current density of 1 mA∙cm⁻² in neutral conditions. The CPE experiment revealed that (EDAI)(H₂O)MnPi remained active for at least 10 h. Manganese phosphate nanosheets containing a rich, extensive, and continuous hydrogen bond network exhibited improved OER performance in neutral conditions. The hydrogen-bonding network in manganese phosphate nanosheets has similar functions to the hydrogen-bonding network in PSII, which could accelerate the transfer rate of protons and facilitate electrocatalytic water oxidation. This study may provide guidance for the design of water oxidation catalysts with rich hydrogen bond network.     

Solid-liquid Phase Equilibria in the Process of Producing Lithium Hydroxide from Lithium Sulfate

The solid-liquid phase equilibria in the process of producing lithium hydroxide from lithium sulfate at 283.15, 298.15 and 323.15 K were studied via the isothermal solubility equilibrium method, and the solid species, phase diagrams, solution densities and pH were determined. The results show that four solid species of Na₂SO₄·10H₂O, Na₂SO₄·2.5H₂O, Na₂SO₄ and LiOH·H₂O occurred in the system, among them, Na₂SO₄·2.5H₂O was a new solid species not reported in the open literature, which was determined via chemical analysis, Karl Fischer water titration, X-ray diffraction(XRD), thermogravimetic analysis(TG) and differential scanning calorimetry(DSC) testing. Based on the SLE data, one systemic process to produce LiOH·H₂O from Li₂SO₄·H₂O was proposed including two crystallization steps at lower and higher temperatures.     

基于三维多孔活性炭构筑安全、高性能以及长循环寿命的锌离子混合电容器

可充电水系锌离子电池因成本低、环境友好等优点,已经成为目前电化学储能领域的研究热点之一。然而锌离子电池中高容量、长循环寿命的阴极材料的开发仍然是一大难题。为了解决这一问题,本文中通过直接利用锌片做阳极和集流体,采用高比表面积的三维多孔活性炭(3DAC)做阴极构筑了一种锌离子混合电容器(ZIHC)。该ZIHC器件表现出了优异的电化学性能,具有目前文献报道的ZIHC最高的213 mAh·g~(-1)比容量,展示出164Wh·kg~(-1)的高能量密度和9.3kW·kg~(-1)的高功率密度以及优异的循环稳定性(10 A·g~(-1)下循环20000圈之后,容量保持率为90%,库伦效率接近100%)。我们认为这种采用高比表、三维多孔活性炭(3DAC)做阴极构筑的安全、高性能以及长寿命的水系锌离子混合电容器将为下一代高性能储能器件的开发提供新的研究思路。     

Four Coordination Polymers Assembled with a New Biscarboxyl-functionalized Schiff Base Ligand

Based on a new biscarboxyl-functionalized Schiff base ligand 1,2-cyclohexanediamino-N,N'-bis[3-methoxyl-5-(p-carboxyl-phenylazo)] salicylidene(H₄L), four polymers,[(CH₃)₂NH₂]₂·[Mn₃(L)₂(H₂O)₄]·2DMF(CP1),[Fe₂(L)(H₂O)(DMF)](CP2),[(CH₃)₂NH₂]·[Cu(HL)]·H₂O(CP3) and[Ni₂(L)(teta)]·2DMF·H₂O(CP4), have been synthesized(teta=5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). In CP1, both of the internal[N₂O₂] pocket and the external carboxylate groups of L^4- anion are ligated by Mn²⁺ ions, and the structure displays a layer. In CP2, the Fe²⁺ cations are linked by L^4- anions to form a binuclear double chain. CP3 displays a[Cu₂(HL)₂] dimer. In CP4, the Ni²⁺ ions are connected by L^4- anions to form a chain. The structures are further linked by hydrogen bonds to form 2D or 3D supramolecular architectures, respectively. CP1 exhibits adsorption ability to three organic dyes.     

Mechanism of Lithium and Cobalt Recovery from Spent Lithium-ion Batteries by Sulfation Roasting Process

Different from the traditional pyrometallurgical recovery process of Li and Co from spent lithium-ion batteries, a new recovery method for Li and Co was established by converting LiCoO₂ into water-soluble metal sulfates by roasting a mixture of LiCoO₂ and NaHSO₄·H₂O. The evolution law of the mixture with increased roasting temperature was investigated by thermogravimetry-differential scanning calorimetry(TG-DSC), in situ X-ray diffraction(XRD), XRD, and X-ray photoelectron spectroscopy(XPS). The results show that the phase transition of LiCoO₂ mixed with NaHSO₄·H₂O with increased temperature proceeded as follows:LiCoO₂, NaHSO₄·H₂O→LiCoO₂, NaHSO₄→Li_1-xCoO₂, LiNaSO₄, Na₂S₂O₇, Na₂SO₄→Li_1-xCoO₂, Co₃O₄, LiNaSO₄, Na₂SO₄→Co₃O₄, LiNaSO₄. The reaction mechanism of this roasting process may be as follows:LiCoO₂+NaHSO₄·H₂O→1/2Li₂SO₄+ 1/2Na₂SO₄+1/3Co₃O₄+1/12O₂+3/2H₂O, Li₂SO₄+Na₂SO₄=2LiNaSO₄.     

Infrared study of νOD modes in isotopically dilute (HDO) isostructural compounds M(HCOO)2·2H2O (M=Mn,Fe,Co,Ni,Cu,Zn) with matrix-isolated guest ions (Cu in M(HCOO)2·2H2O and M in Cu(HCOO)2·2H2O)

The infrared spectra of isotopically dilute (matrix-isolated HDO molecules) isostructural compounds M(HCOO)₂·2H₂O (M=Mn,Fe,Co,Ni,Zn,Cu) are presented and discussed in the region of the OD stretching modes. According to the structural data the compounds under study are divided into two groups: in M(HCOO)₂·2H₂O (M=Mn,Ni,Zn) the H₂O(1) molecules form stronger hydrogen bonds as compared to H₂O(2); in M(HCOO)₂·2H₂O (M=Fe,Co,Cu) the H₂O(2) molecules form stronger hydrogen bonds as compared to the H₂O(1) molecules. The influence of the metal–water interactions (synergetic effect) and the unit-cell volumes (repulsion potential of the lattice) on the hydrogen bond strength within the isostructural series is discussed. The wavenumbers of the uncoupled OD stretching modes of the HDO molecules influenced by guest ions (Cu²⁺ ions matrix-isolated in M(HCOO)₂·2H₂O and M²⁺ ions matrix-isolated in Cu(HCOO)₂·2H₂O) are presented and commented. For example, the analysis of the spectra reveals that when Cu²⁺ ions are included in the structure of M(HCOO)₂·2H₂O the hydrogen bonds of the type M–OH₂OCHO–Cu are considerably weaker as compared to those of the same type formed when M²⁺ ions are included in the structure of Cu(HCOO)₂·2H₂O if the cations remain unchanged.     

THE CRYSTAL STRUCTURE OF RARE EARTH COMPLEX WITH AMINO ACIDS Ⅱ The Crystal Structure of Gtutamate Comptex of Erbium Perchtorate

The crystat structure of {[Er_2(L—Glu)_2(H_2O)_6](ClO_4)_2·3H_2O)_2 has been studied by X-ray diffraction. The crystal is monoctinic with space group P2_1 and cell parameters a=19.987(3) , b=16.505(3) , c=11.040(2) , β=104.69(1)~o, V=3538(1) , Z=2, Dc=2.29 g. cm~(-3), μ=53.2 cm~(-1), F(000)=2384. The asymmetric unit contains two complex motecules and four centre ions. Each erbium (Ⅲ) is coordinated by five oxygen donors from four different glutamates and four oxygen donors from the aqua ligand to form a nine coordination potyhedron. The mean distances of Er—0 (carboxylate) and Er—Ow are 2.439 and 2.41 respectivety. The finat R and Rw are 0.043 and 0. 058, respectivety.