Synthesis of zeolite A and zeolite X from electrolytic manganese residue,its characterization and performance for the removal of Cd^(2+)from wastewater

Electrolytic manganese residue(EMR)can cause serious environmental and biological hazards.In order to solve the problem,zeolite A(EMRZA)and zeolite X(EMRZX)were synthesized by EMR.The pure phase zeolites were synthesized by alkaline melting and hydrothermal two-step process,which had high crystallinity and excellent crystal control.And the optimum conditions for synthesis of zeolite were investigated:NaOH-EMR mass ratio=1.2,L/S=10,hydrothermal temperature=90℃,and hydrothermal time=6 h.Then,EMRZA and EMRZX showed excellent adsorption of Cd^(2+).When T=25℃,time=120min,pH=6,C0=518 mg·L^(-1),and quantity of absorbent=1.5 g·L^(-1),the adsorption capacities of EMRZA and EMRZX reached 314.2 and 289,5 mg·g^(-1),respectively,In addition,after three repeated adsorption-desorption cycles,EMRZA and EMRZX retained 80%and 74%of the initial zeolites removal rates,respectively.Moreover,adsorption results followed quasi-second-order kinetics and monolayer adsorption,which was regulated by a combination of chemisorption and intra-particle diffusion mechanisms.The adsorption mechanism was ions exchange between Cd^(2+)and Na+.In summary,it has been confirmed that EMRZA and EMRZX can be reused as highly efficient adsorbents to treat Cd^(2+)-contaminated wastewater.

Inhibiting manganese(Ⅱ)from catalyzing electrolyte decomposition in lithium-ion batteries

A once overlooked source of electrolyte degradation incurred by dissolved manganese(Ⅱ)species in lithium-ion batteries has been identified recently.In order to deactivate the catalytic activity of such manganese(II)ion,1-aza-12-crown-4-ether(A12C4)with cavity size well matched manganese(Ⅱ)ion is used in this work as electrolyte additive.Theoretical and experimental results show that stable complex forms between A12C4 and manganese(II)ions in the electrolyte,which does not affect the solvation of Li ions.The strong binding effect of A12C4 additive reduces the charge density of manganese(II)ion and inhibits its destruction of the PF_(6)^(-)structure in the electrolyte,leading to greatly improved thermal stability of manganese(II)ions-containing electrolyte.In addition to bulk electrolyte,A12C4 additive also shows capability in preventing Mn^(2+) from degrading SEI on graphite surface.Such bulk and interphasial stability introduced by A12C4 leads to significantly improved cycling performance of LIBs.

Synthesis, Crystal Structure and Theoretical Calculation of a Novel 2D Network of Manganese(Ⅱ) Complex

A novel complex, [Mn(2-NCP)(H2BTC)(H2O)]n(1, 1,3,5-H3BTC = 1,3,5-benzenetricarboxylic acid, 2-HNCP = 2-(2-carboxyphenyl)-1 H-imidazo(4,5-f)-(1,10)phenanthroline), was hydrothermally synthesized and structurally characterized by elemental analysis, IR, XRD and single-crystal X-ray diffraction. Structural analyses reveal that complex 1 exhibits a(6, 6)-connected topology network with a Schlafli symbol of(6^3). The adjacent 2D layers are further stacked via strong hydrogen-bonding interactions, giving a 3 D supramolecular framework. In addition, the structure of complex 1 was calculated by the B3LYP/LANL2 DZ method by Gaussian program. The results from natural bond orbital(NBO) analysis shows obvious covalent interaction between the coordinated atoms and Mn(Ⅱ) ion.

Synthesis and Characterization of a Homochrial Manganese(Ⅱ)Complex Constructed from (1R,2R)-(-)-Diaminocyclohexane-N,N biscarboxyl-salicylidene)

A homochrial manganese（Ⅱ） complex derived from chiral salen ligand （1R,2R）-（-）diaminocyclohexane-N,N-biscarboxyl-salicylidene） （1） has been synthesized through solvothermal procedure and characterized by IR,elemental analysis,TGA,circular dichroism （CD）,powder and single-crystal X-ray crystallography.It crystallizes in monoclinic,space group C2 with a=32.987（7）,b=7.4662（15）,c=17.931（4）,β=97.82（3）°,V=4375.0（15） 3,Z=8,D c=1.544 g/cm 3,F（000）=2096,M r=508.36,μ=0.658 mm-1,the final GOOF=0.975,R=0.0676 and wR=0.2068 for 6357 observed reflections with I 2σ（Ⅰ）.The coordination polymer 1 possesses a 1D infinite zigzag chain architecture constructed by the dicarboxyl-functionalized metallosalen ligand （MnSalen）,and the polymeric chains are further assembled into a 2D supramolecular network structure via strong intermolecular hydrogen bonding interactions between the adjacent zigzag chains.

A New Manganese(Ⅱ) Coordination Compound Constructed by 1,10-Phenanthroline Derivative and Chlorine Anions: Synthesis, Crystal Structure and Theoretical Calculation

The new manganese(Ⅱ) coordination compound,[Mn(Cl)2(L)2](1, L = 11-fluorodipyrido[3,2-a:2?,3?-c]phenazine), has been achieved under hydrothermal conditions. The structure of compound 1 was determined by single-crystal X-ray diffraction. 1 crystallizes in monoclinic system, space group C2/c with a = 8.419(2), b = 12.286(2), c = 28.451(6)A,β= 95.889(3)°, V =2927.5(10)A3, Z = 4, C36 H16 MnF2 Cl2 N8, Mr = 724.41, Dc = 1.644 g/cm3, F(000)= 1460,μ(Mo Ka)= 0.691 mm-1, R = 0.0445 and wR = 0.0982. Adjacent compounds are stacked by one type of π-πinteraction among L ligands to generate a 1D supramolecular chain. Further, the 1D supramolecular chains are stacked by another type of π-π interaction among L ligands to give a 2D supramolecular layer. Moreover, the C-F···π interactions between the carbon atom of the L ligand and the pyrazine ring of the adjacent L ligand further stabilize the supramolecular layer of 1. In addition, natural bond orbital(NBO) analysis has been calculated by the B3LYP/LANL2DZ method, which shows obvious covalent interaction between the coordinated atoms and Mn(Ⅱ) ion.

Syntheses and Characterizations of Two Manganese(Ⅱ)Coordination Polymers Containing Three-dimensional Interpenetrating Networks Constructed by Mixed Ligands

Two new three-dimensional coordination polymers, namely [Mn（L）（bpdc）]n（1）, [Mn（L）0.5（ndc）]n（2）（L = 1,4-bis（2-methylbenzimidazole）butane, H2 bpdc = 4,4＇-biphenyldicarboxylic acid, H2 ndc = 2,6-naphthalenedicarboxylic acid） have been successfully synthesized under hydrothermal conditions. Two complexes were characterized by physico-chemical, spectroscopic methods and single-crystal X-ray diffraction. Complex 1 shows a 3D → 3D 5-fold interpenetrated network with a 4-connected uninodal dia topology. Complex 2 possesses a 3D → 3D 3-fold interpenetrating architecture with a binodal（4,5）-connected xah topology. The fluorescence and thermal properties of the title complexes were discussed.

Synthesis and Crystal Structure of a Three-dimensional Manganese(Ⅱ)Complex Constructed via Covalent and Hydrogen Bonds

The assembly of 1,4-benzenedicarboxylic acid (H2bdc), 4,4?bipyridine (4,4?bipy), trimethyltin chloride and MnBr24H2O in hydrothermal conditions gave rise to a hydrogen-bonded three-dimensional complex {[Mn(4,4?bipy)4H2O](bdc)}n which has been characterized by single- crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group P2/n with a = 7.0001(2), b = 11.5540(3), c = 11.4192(1) ? = 101.754(2)? V = 904.21(4) 3, Z = 2, C18H20MnN2O8, Mr = 447.30, Dc = 1.643 g/cm3, F(000) = 462 and m(MoK? = 0.783 mm-1. The final R and wR are 0.0499 and 0.1301, respectively for 1335 observed reflections with I ≥ 2(I). The Mn (Ⅱ) is six-coordinated in a distorted octahedral geometry. 4,4?Bipyridine in a m-bridge mode links [Mn(H2O)4]2+ into a linear cation chain. bdc acts as a counter anion and links the linear chains into a three-dimensional structure through hydrogen bonds.

Synthesis and Structure Characterization of a Manganese(Ⅱ) Complex With Eight Coordination Geometry: [Mn(O_2CMe)_2(phen)_2]

The title compound [Mn（O2CMe）2（phen）2] （phen = 1,10-phenanthroline） 1 has been synthesized and structurally determined by single-crystal X-ray diffraction. The crystal is of orthor- hombic, space group Pbcn, with a = 12.554（4）, b = 10.168（3）, c = 17.704（5）A, V= 2259.7（12）A^3 Z = 4, C28H22MnN4O4, Mr= 533.44, Dc= 1.568 g]cm^3, F（000） = 1100, Rint = 0.0242, T= 293（2） K and p = 0.631 mm^-1. The final R = 0.0687 and wR = 0.1960 for 2046 observed reflections with I 〉 20（/）. The structure of the complex consists of one Mn（II） core coordinated by two bidentate-bound CH3COO^- groups and two η^2-phen groups forming an eight-coordinate geometrical configuration.

Hydrothermal Synthesis, Crystal Structure and Magnetic Properties of a Novel Zero-dimensional Manganese(Ⅱ) Complex with 2,2′-Diphenic Acid and 1,10-Phenanthroline Ligands

A novel metal-organic coordination polymer [Mn3（2,2′-dipha）3（phen）6]n·3nH2O （2,2′-dipha = 2,2′-diphenic acid, phen = 1,10-phenanthroline） 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, and magnetic susceptibility measurements. The crystal crystallizes in triclinic, space group P1 with a = 16.921（5）, b = 18.307（5）, c = 18.450（5）A , α = 113.369（5）, β = 108.529（5）, γ = 102.984（5）°, V = 4553（2）A^ 3, C114H72Mn3N12O14.25, Mr = 2002.66, Dc = 1.461 g/cm^3, μ（MoKα） = 0.488 mm^-1, the final F（000） = 2058, Z = 2, R = 0.0491 and wR = 0.0980 for 9087 observed reflections （I 〉 2σ（I））. In the crystal structure, the manganese atom is six-coordinated with two carboxylate oxygen atoms from different carboxylate groups of the same dipha and four nitrogen atoms from two different phen ligands, showing a slightly distorted octahedral geometry. Fur- thermore, it exhibits a zero-dimensional structure with dipha-Mn-phen- as building units. Variable- temperature magnetic measure shows an overall anti-ferromagnetic behavior for compound 1.

Adsorption equilibrium and kinetics studies of divalent manganese from phosphoric acid solution by using cationic exchange resin

There are numerous impurities in wet-process phosphoric acid,among which manganese is one of detrimental metallic impurities,and it causes striking negative effects on the industrial phosphoric acid production and downstream commodity.This article investigated the adsorption behavior of manganese from phosphoric acid employing Sinco-430 cationic ion-exchange resin.Resorting FT-IR and XPS characterizations,the adsorption mechanism was proved to be that manganese was combined with sulfonic acid group.Several crucial parameters such as temperature,phosphoric acid content and resin dose were studied to optimize adsorption efficiency.Through optimization,removal percentage and sorption capacity of manganese reached 53.12 wt%,28.34 mg·g^-1,respectively.Pseudo-2nd-order kinetic model simulated kinetics data best and the activation energy was evaluated as 6.34 kJ·mol^-1 for the sorption reaction of manganese.In addition,the global adsorption rate was first controlled by film diffusion process and second determined by pore diffusion process.It was found that the resin could adsorb up to 50.24 mg·g^-1 for manganese.Equilibrium studies showed that Toth adsorption isotherm model fitted best,followed by Temkin and Langmuir adsorption isotherm models.Thermodynamic analysis showed that manganese adsorption was an endothermic process with enhanced randomness and spontaneity.

Catalysis of Manganese(II) on Chromium(VI) Reduction by Citrate

The catalysis of manganese(II) (Mn2+) on chromium(VI) (Cr6+) reduction by citrate was studied through batch experiments with the concentration of citrate greatly in excess of Cr6+ at 25℃and in pH ranges of 4.0 to 5.0. Results showed that at pH 4.5 within 22 h direct reduction of Cr6+ by citrate was not observed, but for the same time when Mn2+ (50 to 200μmol L-1) was added, nearly all Cr6+ was reduced, with the higher initial Mn2+ concentration having faster Cr6+ reduction. In the initial stage of the reaction, the Cr6+ reduction could be described with a pseudo-first-order kinetics equation. In the later stage of the reaction, plots of lnc(Cr6+) versus t, where c(Cr6+) is the Cr6+ concentration in the reaction and t is the reaction time, deviated from the initial linear trend. The deviations suggested that the pseudo-first-order kinetics did not apply to the whole experimental period and that some reaction intermediates could have greatly accelerated Cr6+ reduction by citrate. The catalysis of the intermediates increased with the reaction time and gradually reached stability. Then, the plot of lnc(Cr6+) versus t in the presence of Mn2+ was linear again, with the rate constant increasing by 102 times compared with the absence of Mn2+. Complexation between Mn2+ and citrate was likely a prerequisite for the catalysis of Mn2+ on the reaction. Additional experiments showed that introducing ethylenediaminetetraacetic acid (EDTA) into the reaction system strongly suppressed the catalysis of Mn2+.

Hydrothermal Synthesis and Crystal Structure of a Manganese(II) Coordination Polymer with 1,1′-Biphenyl-2,2′,6,6′-tetracarboxyl Acid and 2,2′:6,2′′-Terpyridine Ligands

The title compound {[Mn（H2BPTC）（tpy）（H2O）]·（H2O）3}, （1, H4BPTC = 1,1＇- biphenyl-2,2＇,6,6＇-tetracarboxylic acid, tby = 2,2＇：6,2＇-terpyridine） has been synthesized by the hydrothermal reaction, and its structure was determined by X-ray diffraction and characterized by elemental analysis, IR spectrum and thermogravimetric analysis. The crystal is of monoclinic, space group P21/c with a = 10.971（2）, b = 20.776（4）, c = 14.332（3） A, β = 109.25（3）°, MnC31H27N3O12, Mr = 688.50, V= 3084.1（10） A^3, Dc = 1.483 g/cm^3, F（000） = 1420, p = 0.498 mm^-1, S = 1.066 and Z = 4. The final refinement gave R = 0.0447 and wR = 0.1103 for 5107 observed reflections with I 〉 2σ（I）. The title complex has a {[Mn（H2BPTC）（tpy）（H2O）]}, chain structure, and the hydrogen bonding interactions make it more stable. Each chain is further connected to the adjacent ones through π…π, C-H…π and rich hydrogen bonds to form a metal-organic coordination polymer.

Synthesis and Structure Characterization of a Tetranuclear Manganese(Ⅲ) Complex:[Mn_4O_2(O_2CMe)_6(MeOH)_2(dbm)_2]·2MeCOOH·2CH_2Cl_2

The title compound, [Mn4O2（O2CMe）6（MeOH）2（dbm）2]·2MeCOOH·2CH2Cl2 （Hdbm = dibenzoylmethane）, has been synthesized and structurally determined by single-crystal X-ray diffraction. The crystal belongs to triclinic, space group P/, with a = 10.729（3）, b = 12.269（3）, c = 13.085（4） A, a = 106.367（3）,β = 107.643（2）, γ = 94.771（2）°, V = 1547.9（7） A^3, Z = 1, C50H64Cl4Mn4O24, Mr= 1410.57, Dc= 1.513 g/cm^3, F（000） = 724, Rint = 0.0147, T= 293（2） K and p = 1.046 mm ^-1. The final R = 0.0359 and wR = 0.0938 for 5791 observed reflections with 1 〉 2σ（/）. The structure of the complex consists of one [Mn4（μ3-O）2]^8＋ core with four coplanar Mn atoms disposed in an extended ＂butterfly-like＂ arrangement and two O atoms triply bridging each ＂wing＂, and the peripheral ligation is provided by six by-MeCO2^-, two terminal ,μ2-dbm- groups at the two ends of the molecule, and two MeOH molecules on the central Mn atoms, lntermolecular O…H-O hydrogen bonding interactions are found within the structure of the compound.

Synthesis and Crystal Structure of a Manganese(Ⅱ) Complex with 2-(4′-Chlorine-benzoyl)-benzoic Acid and 1,10-Phenanthroline

A new metal-organic complex Mn2（cbba）4（phen）2 （Hcbba = 2-（4＇-chlorine-benzoyl）- benzoic acid, phen = 1,10-phenanthroline） 1 has been hydrotherrnally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses and IR spectroscopy. The compound crystallizes in orthorhombic, space group Pbcn with α = 12.154（5）, b = 18.166（7）, c = 31.197（13） A, V = 6887（5） A^3, C80H48Cl4Mn2N4O12, Mr= 1508.90, Dc = 1.455 g/cm^3, μ（MoKα） = 0.591 mm^-1, F（000） = 3080, Z = 4, the final R = 0.0408 and wR = 0.0873 for 4033 observed reflections （I 〉 2σ（I））. In the crystal structure, the manganese atom is six-coordinated with four carboxylate oxygen atoms from three different cbba ligands and two nitrogen atoms from phen ligands, showing a distorted octahedral geometry. Furthermore, it exhibits a 3D supramolecular network through π-π interactions.

Carbon-coated manganese dioxide nanoparticles and their enhanced electrochemical properties for zinc-ion battery applications

In this study, we report the cost-effective and simple synthesis of carbon-coated α-MnOnanoparticles(α-MnO@C) for use as cathodes of aqueous zinc-ion batteries(ZIBs) for the first time. α-MnO@C was prepared via a gel formation, using maleic acid(CHO) as the carbon source, followed by annealing at low temperature of 270 °C. A uniform carbon network among the α-MnOnanoparticles was observed by transmission electron microscopy. When tested in a zinc cell, the α-MnO@C exhibited a high initial discharge capacity of 272 m Ah/g under 66 m A/g current density compared to 213 m Ah/g, at the same current density, displayed by the pristine sample. Further, α-MnO@C demonstrated superior cycleability compared to the pristine samples. This study may pave the way for the utilizing carbon-coated MnOelectrodes for aqueous ZIB applications and thereby contribute to realizing high performance eco-friendly batteries.

配体辅助Ni(Ⅱ)离子印迹材料的制备及性能

采用沉淀聚合法,以Ni(Ⅱ)离子为模板离子,邻氨基吡啶为配体,丙烯酰胺为功能单体,系统优化印迹条件,制备一系列Ni(Ⅱ)离子印迹聚合物Ni(Ⅱ)-IIP_(1-20)及相应的非印迹聚合物Ni(Ⅱ)-NIP_(1-20)。采用SEM(扫描电镜)、FT-IR(红外光谱)等对较优条件下制备的Ni(Ⅱ)-IIP_(3)及Ni(Ⅱ)-NIP_3进行结构表征,通过动力学吸附实验和等温吸附实验等进一步探究其吸附行为。结果表明:Ni(Ⅱ)-IIP_3对Ni(Ⅱ)离子的平衡吸附量达109.48 mg/g,印迹因子为3.70,是典型的介孔材料。其表面存在吸附Ni(Ⅱ)离子的特异性印迹孔穴,吸附行为更符合准二级动力学模型和Freundlich等温吸附模型。此外,在“竞争离子”Co(Ⅱ)离子存在的条件下,Ni(Ⅱ)-IIP_3对Ni(Ⅱ)离子仍具有较强的吸附能力和良好的吸附选择性,是一种性能优异的新型吸附材料。

基于双功能单体的Ni(Ⅱ)离子印迹复合膜的制备及性能研究

采用沉淀聚合法,以Ni(Ⅱ)离子为模板离子,α-甲基丙烯酸和N-异丙基丙烯酰胺为双功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,通过正交试验设计,对制备Ni(Ⅱ)离子印迹复合膜的实验条件进行系统优化,制备了16种Ni(Ⅱ)离子印迹复合膜[Ni(Ⅱ)-IICMs]和相应的非印迹复合膜(NICMs),得出制备Ni(Ⅱ)-IICMs的较优实验条件。采用平衡吸附实验对Ni(Ⅱ)-IICMs和NICMs进行吸附量和印迹因子评价,结果表明:在较优实验条件下制备的Ni(Ⅱ)-IICM_(8),平衡吸附量为1.286mmol/g,印迹因子为1.737。采用红外光谱、扫描电镜、氮气吸附/脱附等手段对Ni(Ⅱ)-IICM_(8)和相应NICM_(8)的内部结构及表面形貌进行表征。使用动力学吸附和等温吸附实验对Ni(Ⅱ)-IICM_(8)和NICM_(8)的吸附行为进行研究,结果表明:Ni(Ⅱ)-IICM_(8)对Ni(Ⅱ)离子的吸附,在较短时间内即可快速达到吸附平衡,且在不同浓度的溶液中都有较好的吸附效果。在不同温度下,探究Ni(Ⅱ)-IICM_(8)的吸附行为,结果表明Ni(Ⅱ)-IICM_(8)具有良好的“温度响应性”。综上所述,说明实验研究制备的Ni(Ⅱ)-IICM_(8),有望用于实际样品中Ni(Ⅱ)离子的分离和去除。

β-二氧化锰纳米纤维用作Pb(Ⅱ)全固态离子选择性电极转导层的性能研究

本研究通过在还原氧化石墨烯(rGO)上原位生长的β-二氧化锰纳米纤维(β-MnO_(2)NF),合成了一种兼具强疏水性和高界面电容的β-MnO_(2) NF/rGO纳米材料。开发出了一种基于β-MnO_(2) NF/rGO的敏感检测Pb(Ⅱ)的固态离子选择性电极传感器。同时,考虑到转导层如何对离子选择性系数产生作用仍然未知,研究人员利用数值模拟构建了一个耦合了转导层的转导层-膜-溶液界面模型,其考虑了膜-转导层这一界面,构建了一个两界面三相的浓度梯度模型,并据此给出了相应的电位显示,同时还根据其模拟结果计算了相对应的离子选择性系数。

Spectrophotometric Simultaneous Determination of Zinc(II), Manganese(II) and Iron(II) in Pharmaceutical Preparations Using OSC-PLS

This work reports the spectrophotometric simultaneous determination of zinc（Ⅱ）, manganese（Ⅱ） and iron（Ⅱ） in pharmaceutical preparation, using orthogonal signal correctionpartial least squares （OSC-PLS）. All the factors affecting on the sensitivity were optimized and the linear dynamic range for determination of these metals was found. The PLS modeling was used for the multivariate calibration of the spectrophotometric data. The OSC was used for preprocessing of data matrices and the prediction results of model. The experimental calibration matrix was designed by measuring the absorbance over the range 450-570 nm for 21 samples of 0.05-1.05, 0.10-1.10 and 0.05-1.05μg·mL^-1 of zinc（Ⅱ）, manganese（Ⅱ） and iron（Ⅱ）, respectively. The RMSEP for zinc（Ⅱ）, manganese（Ⅱ） and iron（Ⅱ） using OSC-PLS were 0.0164, 0.0132, 0.0146, respectively. The proposed method was successfully applied the determination of zinc（Ⅱ）, manganese（Ⅱ） and iron（Ⅱ） in pharmaceutical preparations.

Synthesis and characterization of multidoped lithium manganese oxide spinel LiCo_(0.02)La_(0.01)Mn_(1.97)O_(3.98)Cl_(0.02)

Multidoped spinel LiCo0.02La0.01Mn1.97O3.98Cl0.02 was synthesized by solid-state method. The structure and electrochemical performance were characterized by XRD, ESEM, particle size distribution analysis, specific surface area testing, galvanostatic cycling and electrochemical impedance spectroscopy. The XRD analysis shows that the sample exhibits pure spinel phase. The substitution of Co, La for Mn and Cl for O in the LiMn2O4 stabilizes the structural integrity of the spinel host, which in turn increases the electrochemical cycleability. The electrochemical experiments confirm that the capacity of the LiCo0.02La0.01Mn1.97O3.98Cl0.02 electrode maintains 90.6% of the initial capacity at 180th cycle.