二维金纳米阵列制备及其光学响应

有序贵金属纳米结构由于其本身所特有的光学响应及灵活调控能力,在微纳光电子材料与器件研究领域得到了广泛应用。在众多相关研究中,如何实现金(Au)纳米周期结构的大面积快速制备是人们关心的重要问题之一。采用纳米球自组装刻蚀方法,在大孔周期结构模板内部成功制备了新型二维Au纳米阵列,并有效避免了杂散Au纳米颗粒的产生。通过进一步的工艺优化和参量控制,实现了Au纳米颗粒尺寸的灵活调控,并探讨了其结构形成的物理机理。光学测试研究结果揭示了二维Au纳米阵列的表面等离子体吸收与散射响应,并证明其在近红外飞秒脉冲激励下具有显著的双光子吸收(饱和)效应。该研究结果在太阳能电池,光开关及材料微纳制备等领域具有潜在应用。

纳米金属材料的研究进展

纳米金属材料具有奇异的结构和特异的功能,与粗晶材料相比,其电学、热学、力学、磁学、光学等性能发生了很大变化。介绍了现有纳米金属材料的相关技术,对一些主要的制备工艺及存在的问题作了较为详细的阐述,并结合纳米金属材料在国内外的研究现状展望了纳米金属材料研究开发与工业化应用等方面的发展趋势。

光学超材料研究进展与发展趋势分析

介电常数与磁导率同时为负值的双负物质(电磁超材料中的一类)具有的特异物理性质,引起全球研究者的关注。因在其中电磁波传播特性与在常规介质中不同,使其在通讯、医药、军事、生物及成像等众多领域具有巨大的、潜在的应用。近年来,对超材料尤其是光频负折射材料(Negative Index Materials,NIMs)方面的研究进展突飞猛进。线性光学超材料的新结构、降噪、调谐,非线性光学超材料具有的新规律,光学超材料优化设计与制备工艺,光学超材料的潜在应用等研究进展在此予以综述,并对各研究分支可能的发展方向予以展望。

热压印刻蚀技术

纳米压印技术是一种高分辨率、廉价、高效的纳米结构制备技术。它既继承了传统光刻技术所具有的并行性，又同时拥有传统光刻技术不易达到的纳米结构制备能力，这为今后纳米结构的广泛应用提供了良好的条件。文章介绍了纳米热压印技术中核心工艺流程，包括：模板的制备、抗粘层的制备、压印过程中温度与压力的影响、反应离子刻蚀，并且给出了利用纳米热压印技术制备的光栅结构，最后展望了纳米压印技术的前景。

Sb_(2)S_(3) nanorods/porous-carbon composite from natural stibnite ore as high-performance anode for lithium-ion batteries

To avoid the high purity reagents and high energy consumption involved in the manufacturing of lithium-ion battery anode materials,Sb_(2)S_(3) nanorods/porous-carbon anode was prepared by remodeling natural stibnite ore with porous carbon matrix via a simple melting method.Due to the nanostructure of Sb_(2)S_(3) nanorods and synergistic effect of porous carbon,the Sb_(2)S_(3) nanorods/porous-carbon anode achieved high cyclic performance of 530.3 mA·h/g at a current density of 100 mA/g after 150 cycles,and exhibited a reversible capacity of 130.6 mA·h/g at a high current density of 5000 mA/g for 320 cycles.This shows a great possibility of utilizing Sb_(2)S_(3) ore as raw material to fabricate promising anodes for advanced lithium-ion batteries.

Electrochemical Deposition of Ni-W Gradient Deposit and Its Structural Characterization

The Ni-W gradient deposit with nano-structure was prepared by an electrochemical deposition method.X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDXA) indicate that the crystallite size of the deposit decreases from 10.3nm to 1.5nm and the crystal grating aberrance increases with the increase of W content in the growing direction of the deposit. The structure of deposit changes from crystalline to amorphous stepwise with associated increase of crystal grating aberrance, and presents gradient distribution. These show that the deposit isgradient with nano-structure.

Synthesis and Characterization of ZnO Nanostructure by Chemical Spray Pyrolysis Method

Zinc Oxide （ZnO） nanostructure were synthesized by precipitating Zinc Chloride and analyzed structurally and optically. Samples were prepared at different thickness （62, 66, 74, 86, 92, and 110 nm）, and substrate temperature kept at 400 ℃ in all cases. Compressed Nitrogen was used as a cartier gas. The samples of the ZnO films were characterized by X-ray diffraction （XRD）, and atomic force microscopy （AFM）. The XRD results indicated that the synthesized ZnO thin films have a pure wurtzite （hexagonal phase） structure. It can be seen that the highest texture coefficient was in （002） plan for nanostructure films. AFM measurement showed the grain size ranging from 62-86 nm. The optical band gap energy （Ee,） of ZnO nanostructure have two values for the same sample and the Eg decrease with increasing thickness utilizing the optical data using UV-Vis spectrophotometer.

Recent progress on nanostructured conducting polymers and composites:synthesis,application and future aspects

Conducting polymers （CPs） have been widely investigated due to their extraordinary advantages over the traditional materials, including wide and tunable electrical conductivity, facile production approach, high mechanical stability, light weight, low cost and ease in material processing. Compared with bulk CPs, nanostructured CPs possess higher electrical conductivity, larger surface area, superior electro- chemical activity, which make them suitable for various ap- plications. Hybridization of CPs with other nanomaterials has obtained promising functional nanocomposites and achieved improved performance in different areas, such as energy sto- rage, sensors, energy harvesting and protection applications. In this review, recent progress on nanostructured CPs and their composites is summarized from research all over the world in more than 400 references, especially from the last three years. The relevant synthesizing experiences are outlined and abundant application examples are illustrated. The ap- proaches of production of nanostructured CPs are discussed and the efficacy and benefits of newest trends for the pre- paration of multifunctional nanomaterials/nanocomposites are presented. Mechanism of their electrical conductivity and the ways to tailor their properties are investigated. The re- maining challenges in developing better CPs based nanoma- terials are also elaborated.

Chemical synthesis, structure and magnetic properties of Co nanorods decorated with Fe_3O_4 nanoparticles

Magnetic anisotropic nanocomposites have attracted tremendous interests, due to their unexpected properties originating from the interactions of the interfaces except for the intrinsic features. In this work, we develop a facile solution chemistry synthesis method to prepare the one-dimensional(1 D) Co-Fe3O4 heterostructures with hard magnetic property. Interestingly, the Fe precursor firstly decompose and nucleate individually, and then grow on the surface of the hexagonal closed-packed(hcp) Co nanorods(NRs) upon prolonging heating time at higher temperature, which is different from the general seed-mediated growth model. The distribution density of Fe3O4 nanoparticles(NPs) on the surface of the Co NRs can be varied with the addition of Fe source,modulating the values of coercivity and saturation magnetization for the Co-Fe3O4 heterostructures. The as-synthesized Co-Fe3O4 heterostructures maintain the hard magnetic properties with a coercivity value more than 2.5 kOe as well as a saturation magnetization value up to 128.3 emu g-1, indicating the preservation of the anisotropy of the hcp Co NRs.

PdPb bimetallic nanowires as electrocatalysts for enhanced ethanol electrooxidation

Less-expensive but efficient electrocatalysts are essential to accelerate the commercialization of fuel cells.Herein,ultrathin PdPb nanowires(PdPb NWs)with a diameter of around 3.5 nm were prepared by using a one-step hydrothermal method.The introduction of Pb in Pd-based bimetallic nanostructures produced high differences in the morphology from Pd nanoparticles(NPs)to various PdPb NWs.All the as-prepared PdPb NWs exhibited better electrocatalytic activity and durability than Pd NPs due to the synergistic effect.Especially,Pd65Pb35 possessed the highest current density of about 3460 mA mgPd^−1 for the ethanol electrooxidation which was around 6.3 times higher than commercial Pd/C.The high-performance of Pd65Pb35 is attributed to the defect-rich and stable nanowire structure with optimized surface atomic arrangement,as evidenced by high resolution transmission electron microscopy measurements and long-time treatment in an acidic media.The differences in the morphologies and electrocatalytic activities of PdPb NWs with varied Pb contents have also been discussed and analyzed.

Fabrication of Noble metal-semiconductor hybrid nanostructures using phase transfer

An easy and effective solution based procedure for the synthesis of noble metal （both Au and Ag） tipped semiconductor nanomaterials is demonstrated where the metal precursors are taken in water and the semiconductors in organic medium, exploiting the phase transfer and reducing capability of suitably chosen ligands. The phase tranfer route is a generalised approach to form either Ag or Au tips on cadmium chalcogenide nanoparticles and nanorods. While multiple dots of noble metals are formed on the semiconductor nanomaterials initiall~ these coalesce into larger islands with time. The hybrids are characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD）, photoluminescence （PL）, ultraviolet-visible spectroscopy （UV-vis） and X-ray photoelectron spectroscopy （XPS）. A detailed FTIR analysis was also carried out to delineate the role of the ligands in the synthesis.

Rotating magnetic field-controlled fabrication of magnetic hydrogel with spatially disk-like microstructures

Composite biomaterials with controllable mi- crostructures play an increasingly important role in tissue engineering and regenerative medicine. Here, we report a magnetic hydrogel composite with disk-like microstructure fabricated by assembly of iron oxide nanopartides during the gelation process in the presence of rotating magnetic field. It should be mentioned that the iron oxide nanoparticles here were synthesized identically following techniques of Fer- umoxytol that is the only inorganic nanodrug approved by FDA for clinical applications. The microstructure of nano- particles inside the hydrogel was ordered three-dimensionally due to the twist of the aligned chains of magnetic nano- particles which leads to the lowest state of systematic energy. The size of microstructure can be tuned from several micro- meters to tens of micrometers by changing the assembly parameters. With the increase of microstructure size, the magnetothermal anisotropy was also augmented. This result confirmed that the assembly-induced anisotropy can occur even for the several micron aggregates of nanopartides. The rotating magnetic field-assisted technique is cost-effective, simple and flexible for the fabrication of composite hydrogel with ordered microstructure. We believe it will be favorable for the quick, green and intelligent fabrication of some com- posite materials.

Two-photon reduction： a cost-effective method for fabrication of functional metallic nanostructures

Metallic nanostructures have underpinned plasmonic-based advanced photonic devices in a broad range of research fields over the last decade including physics, engineering, material science and bioscience, The key to realizing functional plasmonie resonances that can manipulate light at the optical frequencies relies on the creation of conductive metallic structures at the nanoscale with low structural defects. Currently, most plasmonic nanostructures are fabricated either by electron beam lithography （EBL） or by focused ion beam （FIB） milling, which are expensive, complicated and time-consuming. In comparison, the direct laser writing （DLW） technique has demonstrated its high spatial resolution and cost-effectiveness in three-dimensional fabrication of micro/nanostrucmres. Furthermore, the recent breakthroughs in superresolution nanofabrication and parallel writing have significantly advanced the fabrication resolution and throughput of the DLW method and made it one of the promising future nanofabrication technologies with low-cost and scalability. In this review, we provide a comprehensive summary of the state-of-the-art DLW fabrication technology for nanometer scale metallic structures. The fabrication mechanisms, different material choices, fabrication capability, including resolution, conductivity and structure surface smoothness, as well as the characterization methods and achievable devices for different applications are presented. In particular, the development trends of the field and the perspectives for future opportunities and challenges are provided at the end of the review. It has been demonstrated that the quality of the metallic structures fabricated using the DLW method is excellent compared with other methods providing a new and enabling platform for functional nanophotonic device fabrication.

One-step preparation of novel conjugated porous polymer with tubular structure

A shape-persistent dendritic molecule,tris(4-(2,7-dibromo-9-phenyl-9-fluoren-9-yl)phenyl)amine (TF-6Br),has been readily synthesized in high yield through a concise Friedel-Crafts reaction from triphenylamine and 2,7-dibromo(9-phenyl-fluoren-9-ol).It was further employed as the key building block to achieve the synthesis of conjugated porous polymer via Sonogashira coupling with 1,4-diethynylbenzene.Under experimental reaction conditions,the resulting porous polymer shows exceptionally nanotubular morphology,which further allows for a template-free synthesis of porous carbon nanotubes via thermal treatment at high temperature.The obtained nitrogen-doped carbon nanotubes feature with an improved porosity and high surface area.

Site-controlled formation of InGaAs quantum nanostructures——Tailoring the dimensionality and the quantum confinement

We report on InGaAs quantum disks （QDks） controllably formed on the top （001） facet of nano-patterned GaAs pyramidal platforms. The QDks exhibit pyramidal shape with special facets and varied dimensions, depending on the GaAs pyramidal buffer and the amount of InGaAs deposited. The formation of QDks is explained by the overgrowth of an InGaAs layer and thereafter coalescence of small InGaAs islands. Photoluminescence （PL） characteristics of ensemble QDks and exciton features of individual QDks together demonstrate that we may achieve a transition from zero-dimensional （0D） to two-dimensional （2D） quantum structure with increasing QDk size. This transition provides the flexibility to continuously tailor the dimensionality and subsequently the quantum confinement of semiconductor nanostructures via site-controlled self-assembled epitaxy for device applications based on single quantum structures.