铜基类金刚石结构化合物热电性能研究进展

新能源热电转换技术因其在废热回收、热电制冷、航空航天等领域的广泛应用,面向国家重大需求、助力实现“碳达峰、碳中和”而受到广泛关注。有效提升材料的综合热电性能对拓宽热电材料的应用具有深远的意义。铜基类金刚石结构热电材料因其易于调控的输运特性、高元素丰度和低毒等优点引起了研究者的兴趣,因此总结铜基类金刚石结构热电材料研究进展对提升其性能具有重要的指导意义。本文总结了铜基类金刚石结构系列化合物的晶体结构演变过程、能带结构和声子谱特征;归纳了基于能带结构优化和载流子浓度优化来提升电输运性能的研究概况;概括了本征低晶格热导率的机理和利用声子工程优化热输运性能的规律。最后,总结了铜基类金刚石结构化合物热电材料的优势和目前性能优化的瓶颈,并展望了可能的进一步优化策略。

铜基催化剂结构对烯醛脂肪醇溶液吸附扩散性能的影响

烯醛加氢制备2-丙基庚醇工艺过程中非铬催化剂的开发是实现该工艺绿色化的关键。采用吸附扩散法,考察了原料2-丙基庚烯醛与2-丙基庚醇混合溶液在铜硅、铜铬和铜锌铝等3种不同催化剂表面的吸附及孔道扩散特性;并结合3种不同铜基复合氧化物的结构特征,与其2-丙基庚烯醛液相加氢催化性能进行关联。结果表明:铜硅复合氧化物在考察浓度范围均优先吸附2-丙基庚烯醛,而铜锌铝、铜铬复合氧化物在混合溶液中2-丙基庚烯醛质量分数分别高于4.6%和4.1%时,才优先吸附2-丙基庚烯醛;铜铬复合氧化物具有最大2-丙基庚烯醛吸附选择性、扩散系数和最优催化2-丙基庚烯醛液相加氢性能。

纳米铜基柔性导电薄膜制备现状及前景

纳米铜基导电薄膜具有高导电、高性价比且易与柔性基材结合等优点,在下一代柔性电子产品领域具有广泛的应用前景.然而,纳米铜基导电薄膜在制备的过程中易被氧化,成为制备高导电纳米铜基导电薄膜的难题.文中从油墨配方、印刷方法、烧结方法等方面系统地介绍了纳米铜基柔性导电薄膜的制造方法,着重介绍了目前抗氧化油墨的设计思路,阐明了目前柔性电子先进微纳连接技术的工艺流程,对比了其优缺点及适用范围,并列举了纳米铜基导电薄膜在下一代柔性电子产品领域的典型应用.在此基础上,对纳米铜柔性导电薄膜制造尚存的主要问题进行了总结,并对其未来发展趋势进行了展望.

Modifying element diffusion pathway by transition layer structure in high-entropy alloy particle reinforced Cu matrix composites

The Al0.3CoCrFeNi high-entropy alloy(HEA)particles reinforced Cu matrix composites(CMCs)were fabricated by mechanical alloying and sintering.Transition layer structure was obtained by multi-step ball milling to investigate the related influence on element diffusion behavior and wear properties of CMCs.The results indicate that a new Cu transition layer is generated,and the thickness is about 5μm.Cr element diffuses into the interface via the transition layer,which forms the complex oxide.Because of the structure of Cu transition layer,the diffusion rates of Ni,Co and Fe increase,especially the Ni element.The wear resistance of CMCs is improved by 30%,which is due to the improvement of interface bonding strength,compared with the CMCs without transition layer.This method is applicable to the development of advanced HEA reinforced metallic matrix composites.

Synthesis and Structure of bis(μ-2-aminopyridine N-oxide)-bis[dichlorocopper(II)]

The complex [Cu2（apo）4Cl4]·2H2O （apo=2-aminopyridine N-oxide） was obtained. A single- crystal X-ray study shows that the complex is a binuclear compound （Cu2C20H28Cl4N8O6）. The coordination geometry about each copper atom is best described as a distorted square pyramid. The compound [Cu2（apo）4Cl4]·2H2O belongs to the triclinic system with space group P, lattice constants: a = 7.8550（7）, b = 8.5378（7）, c = 12.082（1） ?, α = 72.807（1）, β = 77.641（1）, γ = 70.800（1）(, V =724.85（11） ?3, Z=1, Mr =745.38, Dc=1.708 g/cm3, μ =1.886mm-1, F（000） =378, R=0.0359, wR2=0.0884 for 2220 reflections with I >2σ（I）. The distances between Cu（II） and O atoms are in the range from 1.934（2） to 2.042（2）?. The distance between two copper atoms Cu-Cu（A） is 3.2978（8） ?. The distances of Cu-Cl（1） and Cu-Cl（2） are 2.2322（9）, 2.5095（10） ?, respectively. There is no evident hydrogen bond between N and Cl.

Photocatalytic activity of CuO nanoparticles incorporated in mesoporous structure prepared from bis(2-aminonicotinato) copper(Ⅱ) microflakes

An easy method for preparing CuO nanoparticles incorporated in a mesoporous structure was presented based on the thermal decomposition of a copper complex. The novel copper coordination compound of [Cu(anic)2]·0.75H2O (anic= 2-aminonicotinate) with the microflake morphology was synthesized through the reaction of 2-aminonicotinic acid (Hanic) and copper(II) nitrate. Using elemental analysis and Fourier transform infrared (FTIR) spectroscopy, the chemical composition of CuC12H11.5N4O4.75 was proposed. Calcination process at 550 °C for 4 h transformed the microflakes into CuO nanoparticles incorporated in a mesoporous structure. The FTIR peaks assigned to 2-aminonicotinate were completely removed after calcination, confirming CuO formation. X-ray diffraction (XRD) analysis also confirmed the generation of pure and crystalline CuO. SEM showed CuO nanoparticles with the average diameter of 75 nm. The diffuse reflectance spectrum (DRS) of the CuO nanoparticles showed a band gap energy of −1.58 eV. The degradation efficiency toward rhodamine B was almost 100 % after 5 h illumination when both CuO and H2O2 were utilized. The results show that the product can be used as an efficient photocatalyst for water treatment.

Microstructures and interfacial interactions of Al_(2)O_(3)whiskers and graphene nano-platelets co-reinforced copper matrix composites

The mechanical properties and microstructures of Al_(2)O_(3)whiskers and graphene nano-platelets(GNPs)co-reinforced Cu-matrix composites were studied.Cu-matrix composites with a variation of GNPs amount were fabricated by mechanical alloying followed by vacuum hot-pressing sintering and hot isostatic pressing.The Cu-matrix composite with 0.5 wt.%GNPs(GNPs-0.5)suggests a good interfacial bonding of both Cu/C and Cu/Al_(2)O_(3)interfaces.Both the hardness and compressive strength of Cu-matrix composites show a consistent tendency that firstly increases to a critical value and then decreases with increasing GNPs amount.It is suggested that the most possible strengthening mechanisms of both GNPs and Al_(2)O_(3)whisker working in the Cu-matrix composites involve energy dissipating and load transfer,as well as grain refinements for GNPs.The synergetic effect of GNPs and Al_(2)O_(3)whiskers is highlighted that the embedded GNPs would hinder the crack path generated at the Al_(2)O_(3)/Cu interface and enhance the already outstanding strengthening effect that Al_(2)O_(3)whiskers provide.

Synthesis and Crystal Structure of Dicyanamide (5,7,7,12,14,14-Hexamethyl-1,4,8,11-tetraazacyclo- tetradecane) Copper(II) Percholatehydrate

The copper(II) complex [Cu(teta)N(CN)2](ClO4)H2O (teta = 5,7,7,12,14,14- hexamethyl-1,4,8,11-tetraazacyclotetradecane) has been synthesized and the crystal structure was determined by single-crystal X-ray diffraction. Crystal data: C18H38ClCuN7O5, monoclinic, space group P21/n, a = 8.796(3), b = 11.885(4), c = 23.054(9) , b = 97.540(4)o, V = 2389.3(15) 3, Mr = 531.54, Z = 4, Dc = 1.478 g/cm3, F(000) = 1124, ?= 1.070 mm-1, the final R = 0.0566 and wR = 0.1162 for 4749 observed reflections (I > 2s(I)). The center copper ion is coordinated by five nitrogen atoms in a square pyramidal geometry, with four from the macrocyclic ligand teta and the other one from a nitrile nitrogen atom of dicyanamide which is coordinated to the metal atoms as uni-dentate manner via nitrile nitrogen atom.

A Pyridine-copper Inclusion Complex of a New Tripodal Ligand

A pyridine-copper inclusion complex with [Cu(py)4Cl]+ core was prepared in the presence of tripodal ligand tbst {tbst = 1,3,5-tris(2-benzimidazol)sulfanylmethyl-2,4,6-trimethyl- benzene}, and its structure has been determined. It crystallizes in triclinic, space group P with a = 9.0822(2), b = 17.6026(4), c = 18.7156(4) ? a = 93.40, b = 91.2980(1), g = 91.5560(1), V = 2984.81(1) 3, C58H63Cl2CuN11O4S3, Mr = 1208.81, Z = 2, F(000) = 1262, Dc = 1.345 g/cm3, m = 0.615 mm-1, R = 0.0713 and wR = 0.1307 for 7798 observed reflections (I > 2s(I)). X-ray analysis reveals that the uncoordinated tbst and pyridine as guest molecules are included in the complex with formula {[Cu(py)4Cl]Cl}(tbst)(py)4H2O. The tbst, pyridine, aqua and Cl- anion in the com- plex form extensive hydrogen-bonding interactions, building up a quasi-dinuclear structure.

Synthesis, Characterization of Mn2＊, Co2＊, Ni2＊, Cu2＊ and Zn2. Complex Salts with 2,3,5-（Triphenyl） Tetrazolium Chloride and the Crystal Structure of [C N4（ C6H5）3]2[C uC 14]

A series of new complex salts of the type [R]2[MC14] where R =[Ph-C=n-N-Ph N=N-Ph],M = Mn2＋, Co2＋, Ni2＋, Cu2＋ and Zn2＋ wereprepared and characterized by elemental analysis, molar conductance, IR and UVNis is spectral studies and magnetic measurements.The crystal structure of[Ph-C=n-N-Ph N=N-Ph]2[CuCl4] was determined by single crystal X-ray crystallography. The structure consisted of anion part and a 2,3,5-（triphenyl） tetrazolium cation as counter ions. The copper complex has a distorted tetrahedral geometry, the CI（1）-Cu-CI（2） [124.33 （2°）] and Cl（3）-Cu-Cl（4） [131.03 （2°）] angles are significantly larger than the ideal tetrahedral. The [CuCI4] anion and its counter ions are connected through a hydrogen bonds between C1 of the dianion and hetero aromatic rings by Cl-π, π-π and C-H … π, interactions.

Crystal Structure of Copper（Ⅱ） Complex with 3－Hydroxyl－1，5－diazacyclooctane

Crystal structure of copper(Ⅱ) complex with a new mesocyclic diamine ligand 3-hydroxyl-1, 5-diazacyclooctane, Cu [C_(12)H_(28)N_4O_2]Br_2, M_r= 483. 7 is reported. It crystallizes in orthorhombic Pbca with a= 16. 201 (5), b=10. 513 (4), c=9. 992(4) A, V=1701. 8(7) A￣3, Z=4, D_c=1. 888 g/cm￣3, μ=49. 5 cm￣(-1) (MoKa),F(000) = 972. The final R and Rto are 0. 039 and 0. 047 for 1052 observed reflections with I≥3σ(I). The result of X-ray structure determination shows that 3hydroxyl-1,5-diazacyclooctane forms a 2 :1 complex with CuBr_2 in which the central copper ion is sandwiched between the two ligands.

Unit Construction in the Formation of Metal Clusters──Investigation on the Metal Cluster CompoundsContaining Fe_2S_2(CO)_6-units

The syntheses and structures of trinuclear Mo (W)-Fe-S cluster[MFe2S2(CO)8 (S,CNSEt2)]- (M=Mo, W), hexanuclear Fe-S cluster [Fe6S6-(CO)12]2- and undecanuclear Cu-Fe-S cluster [Cu5Fe6S6(CO)18(PPh3)2]-, containingFe2S2(CO)6-units bave been summarized and the important vestiges left in their struc-tures reflecting the formation processes of the clusters have been found and discussed.Further inspecting some other typical clusters a regular unit construction in the forma-tion of the metal cluster compounds containing Fe2S2(CO)6-units has been figured outand applied to speculate and predict several new cluster compounds containing Fe2S2(CO)6-units.

Structure Studies on New Types of Macrocyclic Compounds Part Ⅵ. Crystal Structure of Copper(Ⅱ) Complex of 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-N', N'-diaceticacid

The crystal structure of copper(Ⅱ) complex with a new 14-membered tetraazamacrocyclic ligand 5,5,7,12,12,14-hexamethy1-1,4,8,11-tetraazacyclotetradecane-N'N'-diacetic acid,[CuC16N4H34(CH2COO)(CH2COOH)]·ClO4·0. 5HCIO4·1. 5H2O was determined. Crystallographic data: Mr = 639.22,orthorhombic, space group Pcnb with a=11.743(4),b=16.446(2),c=29.611 (4) A,Z=8,V=5726(3) A3, Dc=1.482 g·cm-3, F(000)=1344,μ=9. 64 cm-1,R=0.063,and Rw=0.067 for 2386 reflections with I≥3σ(I). The structure shows an unusual configuration in which two carboxyl groups were bonded to two neighboring nitrogen atoms of the macrocycle, N1 and N4, and six methyl substituents occur on one side of the macrocycle, while two carboxyl groups on the other side, and central copper(Ⅱ) ion forms a five-coordinated geometry.

Copper chalcogenide thermoelectric materials

Cu-based chalcogenides have received increasing attention as promising thermoelectric materials due to their high efficiency,tunable transport properties,high elemental abundance and low toxicity.In this review,we summarize the recent research progress on this large family compounds covering diamond-like chalcogenides and liquid-like Cu2X (X=S,Se,Te)binary compounds as well as their multinary derivatives.These materials have the general features of two sublattices to decouple electron and phonon transport properties.On the one hand,the complex crystal structure and the disordered or even liquid-like sublattice bring about an intrinsically low lattice thermal conductivity.On the other hand, the rigid sublattice constitutes the charge-transport network, maintaining a decent electrical performance.For specific material systems,we demonstrate their unique structural features and outline the structure-performance correlation. Various design strategies including doping,alloying,band engineering and nanostructure architecture,covering nearly all the material scale,are also presented.Finally,the potential of the application of Cu-based chalcogenides as high-performance thermoelectric materials is briefly discussed from material design to device development.