纳米结构ZnOZnO晶体合成方法的研究进展

近年来,纳米结构ZnO在涂料、化妆品、橡胶和复合材料涂层等领域受到了广泛关注.纳米结构ZnO表面具有优异的表面效应与体积效应,故其磁性、光吸收特性、化学活性、催化活性、热阻及熔点等较普通粒子皆发生了很大的变化.纳米结构ZnO的合成方法主要包括水热合成法、化学气相沉积以及溶胶凝胶法.详细介绍了ZnO的结构及其物理性质,论述了几种常见的纳米结构ZnO制备方法,总结了不同制备方法合成纳米结构ZnO的研究进展,最后针对各合成方法的优缺点进行分析.     

纳米化学复合镀技术概述

纳米化学复合镀技术是制备复合材料新方法,主要介绍了纳米化学复合镀镀层形成的吸附机理和前提基础,综述了纳米化学复合镀层的结构特点和优良的功能特性以及目前的研究成果,论述了影响纳米化学复合镀镀层制备的主要因素;探讨了纳米化学复合镀的研究现状和发展趋势。     

基于表面辅助法制备卟啉超分子微纳米结构的研究进展

综述了基于表面辅助法,利用卟啉分子间非共价键相互作用力,制备具有一定尺寸和形貌的卟啉超分子微纳米结构的研究进展.根据卟啉的形貌结构分类,如一维结构、多维结构和球形结构,总结了基于表面辅助法构筑卟啉超分子微纳米结构的制备方法.最后总结和展望,旨在让读者更好地了解表面辅助法用以卟啉超分子微纳米结构的制备,认识到在超分子化学...     

前沿科研成果融入物理化学实验教学 ——金-聚丙烯酸铵双面神纳米粒子的合成

设计了一个还原法制备金溶胶,并进一步合成具有双面神结构的金-聚丙烯酸铵纳米粒子的本科生化学实验.首先,采用溶胶法合成金纳米粒子,然后,聚丙烯酸通过异向生长与金纳米粒子形成具有双面神结构的纳米粒子.本实验可以锻炼学生制备纳米材料的能力,熟悉金纳米粒子的制备方法及其纳米尺度的特殊性质,并掌握仪器设备的使用,认识纳米尺度可操...     

化学法制备纳米氧化铁顔料研究进展

综述了纳米氧化铁化学制备方法的研究进展,对胶体化学法、水热法、固相法、沉淀法和水解法等化学制备方法进行了探讨.通过分析比较,对未来纳米氧化铁的化学制备提出了几点建议.     

纳米SiO2复合水性丙烯酸树脂的制备及形态研究

通过原位聚合和共混两种方法制备水性纳米SiO2复合丙烯酸树脂分散液,利用各种方法研究了纳米复合丙烯酸树脂的化学结构、纳米SiO2的分散形态和涂层表面微观粗糙度.旨在探讨纳米SiO2改性水性丙烯酸树脂涂层的可能途径.     

热处理对掺锑二氧化锡纳米棒结构和导电性能的影响

以SnCl4·5H2O和SbCl3为原料,采用化学共沉淀法制得纳米级掺锑二氧化锡(ATO)的前驱物,在一定条件下热处理,成功制备了直径为10～30nm,长为50～500nm的金红石结构的ATO纳米棒.运用热重分析(TGA)、X射线衍射(XRD)、透射电镜(TEM)及比表面仪(BET法)对纳米棒进行了表征,初步探讨了其形成机理,较系统地研究了热处理温度及热处理时间对粉体形貌结构和导电性能的影响规律.     

复杂Te纳米材料的制备与微结构调控

采用简易高效的微波湿化学方法合成了包括纤维状、棒状、花束状等多尺度Te纳米结构材料.系统地研究了NaOH、PVP的加入量及溶剂EG/EN体积比对Te微观结构形貌的调控及影响作用.该制备工艺操作简单、反应温和且节能环保,除可实现Te纳米结构材料的大规模生产外还对其他纳米级构件的制备起到指导意义.     

纳米结构铁氧体磁性材料的制备和应用

铁氧体纳米磁性材料是一类非常重要的无机功能材料,其应用涉及到电子、信息、航天航空、生物医学等领域。综述了纳米结构铁氧体磁性材料化学制备方法的研究进展,分析了相关纳米结构铁氧体磁性材料的制备工艺对磁性能的影响,以及它们的应用,展望了研究和开发纳米结构铁氧体磁性材料的新性能和新技术的应用前景。     

一维纳米结构有序阵列研究进展

一维纳米结构有序阵列的控制合成与组装是纳米器件应用的关键,综述了这一领域的最新研究进展.一维纳米有序阵列的制备主要有模板法、化学气相沉积法、人工组装法,纳米阵列体系优异的性能使其在纳米激光器、平板显示器、磁记录器、纳米晶体管等具有很大的应用潜力,从而为实现纳米器件产业化奠定基础.     

Profile Prediction and Fabrication of Wet-Etched Gold Nanostructures for Localized Surface Plasmon Resonance

Dispersed nanosphere lithography can be employed to fabricate gold nanostructures for localized surface plasmon resonance, in which the gold film evaporated on the nanospheres is anisotropically dry etched to obtain gold nanostructures. This paper reports that by wet etching of the gold film, various kinds of gold nanostructures can be fabricated in a cost-effective way. The shape of the nanostructures is predicted by profile simulation, and the localized surface plasmon resonance spectrum is observed to be shifting its extinction peak with the etching time.     

Friction-induced nanofabrication method to produce protrusive nanostructures on quartz

In this paper, a new friction-induced nanofabrication method is presented to fabricate protrusive nanostructures on quartz surfaces through scratching a diamond tip under given normal loads. The nanostructures, such as nanodots, nanolines, surface mesas and nanowords, can be produced on the target surface by programming the tip traces according to the demanded patterns. The height of these nanostructures increases with the increase of the number of scratching cycles or the normal load. Transmission electron microscope observations indicated that the lattice distortion and dislocations induced by the mechanical interaction may have played a dominating role in the formation of the protrusive nanostructures on quartz surfaces. Further analysis reveals that during scratching, a contact pressure ranged from 0.4Py to Py (Py is the critical yield pressure of quartz) is apt to produce protuberant nanostructures on quartz under the given experimental conditions. Finally, it is of great interest to find that the protrusive nanostructures can be selectively dissolved in 20% KOH solution. Since the nanowords can be easily 'written' by friction-induced fabrication and 'erased' through selective etching on a quartz surface, this friction-induced method opens up new opportunities for future nanofabrication.     

Various Quantum- and Nano-Structures by III–V Droplet Epitaxy on GaAs Substrates

We report on various self-assembled In(Ga)As nanostructures by droplet epitaxy on GaAs substrates using molecular beam epitaxy. Depending on the growth condition and index of surfaces, various nanostructures can be fabricated: quantum dots (QDs), ring-like and holed-triangular nanostructures. At near room temperatures, by limiting surface diffusion of adatoms, the size of In droplets suitable for quantum confinement can be fabricated and thus InAs QDs are demonstrated on GaAs (100) surface. On the other hand, at relatively higher substrate temperatures, by enhancing the surface migrations of In adatoms, super lower density of InGaAs ring-shaped nanostructures can be fabricated on GaAs (100). Under an identical growth condition, holed-triangular InGaAs nanostructures can be fabricated on GaAs type-A surfaces, while ring-shaped nanostructures are formed on GaAs (100). The formation mechanism of various nanostructures can be understood in terms of intermixing, surface diffusion, and surface reconstruction.     

The role of the symmetry and the flexibility of the anion on the characteristics of the nanostructures and the viscosities of ionic liquids☆

The transport properties of ionic liquids (ILs) are crucial properties in view of their applications in electrochem-ical devices. One of the most important advantages of ILs is that their chemical–physical properties and conse-quently their bulk performances can be well tuned by optimizing the chemical structures of their ions. This will require elucidating the structural features of the ions that fundamentally determine the characteristics of the nanostructures and the viscosities of ILs. Here we showed for the first time that the“rigidity”, the order, and the compactness of the three-dimensional ionic networks generated by the anions and the cation head groups determine the formation and the sizes of the nanostructures in the apolar domains of ILs. We also found that the properties of ionic networks are governed by the conformational flexibility and the symmetry of the anion and/or the cation head group. The thermal stability of the nanostructures of ILs was shown to be con-trolled by the sensitivity of the conformational equilibrium of the anion to the change of temperature. We showed that the viscosity of ILs is strongly related to the symmetry and the flexibility of the constitute ions rather than to the size of the nanostructures of ILs. Therefore, the characteristics of the nanostructures and the viscosities of ILs, especially the thermal stability of the nanostructures, can be fine-tuned by tailoring the symmetry and the conformational flexibility of the anion.     

The Three S's for Aptamer‐Mediated Control of DNA Nanostructure Dynamics: Shape,Self‐Complementarity,and Spatial Flexibility

DNA aptamers are ideal tools to enable modular control of the dynamics of DNA nanostructures. For molecular recognition, they have a particular advantage over antibodies in that they can be integrated into DNA nanostructures in a bespoke manner by base pairing or nucleotide extension without any complex bioconjugation strategy. Such simplicity will be critical upon considering advanced therapeutic and diagnostic applications of DNA nanostructures. However, optimizing DNA aptamers for functional control of the dynamics of DNA nanostructure can be challenging. Herein, we present three considerations—shape, self‐complementarity, and spatial flexibility—that should be paramount upon optimizing aptamer functionality. These lessons, learnt from the growing number of aptamer–nanostructure reports thus far, will be helpful for future studies in which aptamers are used to control the dynamics of nucleic acid nanostructures.     

Growth and Application of ZnO Nanostructures

Nanostructures are the building blocks of future nanodevices and thus methods for fabricating nanostructures of various materials in various forms are fundamentally important. Among those nanostructures ZnO has received much attention over the past few years due to the wide range of research by many different groups focused on different novel nanostructures with different properties. Although ZnO nanowires have been intensively studied, there are only a few methods that showed promising characteristics for practical applications. Without much effort, it can be grown in many different nanostructure forms, thus allowing various novel devices to be achieved. In this study, we intend to review those methods that enable nanostructure growth to be more controllable and feasible for applications. The methods for fabricating ZnO nanostructures are introduced in the first part. In the second part, the application of those nanostructures are mentioned and explained. Finally, the future realization of nanodevices is discussed.     

Morphology control and optical properties of SiGe nanostructures grown on glass substrate

With the rapid progress of nanotechnology, nanostructures with different morphologies have been realized, which may be very promising to enhance the performance of semiconductor devices. In this study, SiGe nanostructures with several kinds of configurations have been synthesized through a chemical vapor deposition process. By controlling growth conditions, different SiGe nanostructures can be easily tuned. Structures and compositions of the nanostructures were determined by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The optical properties of various SiGe nanostructures revealed some dependence with their morphologies, which may be suitable for solar cell applications. The control of the SiGe morphology on nanoscale provides a convenient route to produce diverse SiGe nanostructures and creates new opportunities to realize the integration of future devices.     

Synthesis of different magnetic carbon nanostructures by the pyrolysis of ferrocene at different sublimation temperatures

Various magnetic nanostructures such as Fe nanoparticles (Fe-NPs) adhering to single-walled carbon nanotubes, carbon-encapsulated Fe-NPs, Fe-NP decorated multi-walled carbon nanotubes (MWCNTs), and Fe-filled MWCNTs have been synthesized by the pyrolysis of pure ferrocene. It is found that the formation of the nanostructures can be selectively controlled by simply adjusting the sublimation temperature of ferrocene, while keeping all other experimental parameters unchanged. Magnetic characterization reveals that these nanostructures have an enhanced coercivity, higher than that of bulk Fe at room temperature. Based on the experimental results, the formation mechanism of the nanostructures is discussed in detail.     

Solar energy conversion with tunable plasmonic nanostructures for thermoelectric devices

The photothermal effect in localized surface plasmon resonance (LSPR) should be fully utilized when integrating plasmonics into solar technologies for improved light absorption. In this communication, we demonstrate that the photothermal effect of silver nanostructures can provide a heat source for thermoelectric devices for the first time. The plasmonic band of silver nanostructures can be facilely manoeuvred by tailoring their shapes, enabling them to interact with photons in different spectral ranges for the efficient utilization of solar light. It is anticipated that this concept can be extended to design a photovoltaic-thermoelectric tandem cell structure with plasmonics as mediation for light harvesting.     

Rational manipulation of lattice strain to tailor the electronic and optical properties of nanostructures

Optoelectronic devices with different energy ranges requires materials with different band gaps, sometimes even within the same device. Structural distortions within the nanostructures produce lattice strains, which can change physical properties. However, the detailed knowledge of lattice strains in nanostructures remains confusing. Here, we rationally design and employ a simple and effective scheme to fabricate strained BiVO₄/ZnS nanostructures. Lattice strain originates from lattice distortion caused by the intentional incorporation of metal ions into the inner layer of nanostructures. Experimental findings show that the maximum and minimum band gap energies of BiVO₄/ZnS nanostructures are 2.87 and 2.79 eV under the tensile strain, which are increased by 4.4% and 1.4%, respectively, compared with that of the reference sample (2.75 eV). Impressively, BiVO₄/ZnS nanostructures exhibit tunable dual emission behavior, and lattice strain significantly changes the electron band structure of the nanostructures. In addition, we identify the composite structure of BiVO₄/ZnS nanomaterials and elucidate the mechanistic origin of regulation of the optical and electronic properties by lattice strain in combination with experimental and density functional theory calculations. These results provide a deep understanding of the relationship between lattice strain and optical properties and indicate that strain engineering can be potentially used in the design of nanostructures.