掺杂对纳米ZnO粉末晶粒度和结构的影响

研究了用化学共沉淀方法分别制备的掺杂Bi,Sb,Co,Cr,Mn和多元掺杂对纳米ZnO粉末晶粒度和相结构的影响,发现经500℃／h热处理后,掺Bi,Mn,Co和Cr的粉末晶粒度没有明显变化,而掺Sb的ZnO粉末晶粒度随Sb含量的增加而减小;掺Bi的粉末除主晶相ZnO外还有BiOCl相,掺Sb的粉末有主晶相和尖晶石相,所掺Mn,Co,Cr均固溶于主晶相ZnO;多元掺杂晶粒度均为30nm,相为主晶相和尖晶石相。     

纳米氧化锌晶体的制备与光催化性质

以硝酸锌和改性明胶为原料采用溶胶一凝胶法制备纳米晶体氧化锌，透射电镜和X-射线衍射测试表明其平均粒径约20nm。用稀甲基橙水溶液分别在紫外灯和太阳光照射下测试研究其光催化活性能。试验结果表明，此反应为一级反应，表观速率常数与甲基橙初浓度、催化剂浓度及吸收光强度有关。     

Pulsed laser deposited Al-doped ZnO thin films for optical applications

Highly transparent and conducting Al-doped Zn O(Al:Zn O) thin films were grown on glass substrates using pulsed laser deposition technique.The profound effect of film thickness on the structural, optical and electrical properties of Al:Zn O thin films was observed. The X-ray diffraction depicts c-axis, plane(002) oriented thin films with hexagonal wurtzite crystal structure. Al-doping in Zn O introduces a compressive stress in the films which increase with the film thickness. AFM images reveal the columnar grain formation with low surface roughness. The versatile optical properties of Al:Zn O thin films are important for applications such as transparent electromagnetic interference(EMI) shielding materials and solar cells. The obtained optical band gap(3.2–3.08 e V) was found to be less than pure Zn O(3.37 e V) films. The lowering in the band gap in Al:Zn O thin films could be attributed to band edge bending phenomena. The photoluminescence spectra gives sharp visible emission peaks, enables Al:Zn O thin films for light emitting devices(LEDs) applications. The current–voltage(I–V) measurements show the ohmic behavior of the films with resistivity(ρ) 10-3Ω cm.     

Immobilized ZnO based nanostructures and their environmental applications

In the research of semiconductor metal oxides, zinc oxide(ZnO) nanomaterials have been committed to design and exploration because of their unique physical and chemical properties. ZnO has many structural characteristics and has considerable practical applications in the field of environmental technology. However, ZnO nanomaterials used for environmental functions are often presented in the form of powders. After use, they need to go through recovery processes such as centrifugation and filtrati...     

Nanostructured Electrode Materials for Fuel Cells and Supercapacitors

1 Results Owing to its electrochemical stability, catalytic activity and high electrical conductivity, ruthenium-based oxides have been realized in electrochemistry as excellent electrode materials with applications ranging from electrocatalysts for industrial electrolysis to high power energy storage. Recent studies have suggested that RuOx may have an active role in electrocatalysts for fuel cells.We have been engaged in the fundamental and practical study of nanostructured RuO2-based electrodes[1-5]....     

Research progress in ZnO single-crystal: growth,scientific understanding,and device applications

Zinc oxide, a wide band-gap semiconductor, has shown extensive potential applications in high-efficiency semiconductor photoelectronic devices, semiconductor photocatalysis, and diluted magnetic semiconductors. Due to the undisputed lattice integrity, ZnO single crystals are essential for the fabrication of high-quality ZnO-based photoelectronic devices, and also believed to be ideal research subjects for understanding the underlying mechanisms of semiconductor photocatalysis and diluted magnetic semiconductors. This review, which is organized in two main parts, introduces the recent progress in growth, basic characterization, and device development of ZnO single crystals, and some related works in our group. The first part begins from the growth of ZnO single crystal, and summarizes the fundamental and applied investigations based on ZnO single crystals. These works are composed of the fabrication of homoepitaxial ZnO-based photoelectronic devices, the research on the photocatalysis mechanism, and dilute magnetic mechanism. The second part describes the fabrication of highly thermostable n-type ZnO with high mobility and high electron concentration through intentional doping. More importantly, in this part, a conceptual approach for fabricating highly thermostable p-type ZnO materials with high mobility through an integrated three-step treatment is proposed on the basis of the preliminary research.     

Nanostructured Ion Storage Electrode Materials for Lithium Batteries and Supercapacitors

1 Results Performance of lithium-ion batteries, electrochemical capacitors, and other electric-energy storage devices is not only determined simply by macroscopic chemical composition of their electrode, but also strongly affected by shape and size of the active materials. Nanostructured materials are distinguished from conventional polycrystalline materials by the nanometer size of the structural units that compose them, and they often exhibit properties that are drastically different from the conventi...     

纳米材料制备技术研究进展

综述了近年来在纳米材料制备领域的一些最新研究进展，并对每种制备技术的优缺点进行了比较和评价 。     

树状聚合物功能化碳纳米管/钯纳米复合物的制备及其非酶葡萄糖传感应用

将树状聚合物(PAMAM)通过共价反应嫁接在羧基化碳纳米管(CNTs)表面后用于钯纳米粒子(Pd NPs)的原位沉积,制备成CNTs-PAMAM/Pd NPs复合物。通过壳聚糖包埋将制备的该钯纳米复合物用于玻碳电极的修饰,并通过交流阻抗法和循环伏安法对电极性能进行表征和优化,制备成可用于葡萄糖的安培检测的非酶电化学传感器。实验表明,在最佳实验条件下该传感器可在较短时间内(3 s)实现对葡萄糖的快速稳态安培响应,并可在从0.03 mmol/L至61.7 mmol/L较宽线性范围内实现对葡萄糖的准确测定,检出限为11.5μmol/L。该传感器成本低廉,性质稳定,且具有较好的选择性和重复性,因而在实际应用中具有较好的发展前景。     

Synthesis and Electrochemical Properties of Nanostructured Cathode Materials for Lithium Batteries

1 Results For electrode materials in lithium batteries,a high surface area can provide higher electrode/electrolyte contact areas,thus eventually causing the shorter diffusion paths with the particles,and provides more facile intercalation for Li ions[1-4].In addition,reduced strain of intercalation and contributions from charge storage at the surface may also contribute to Li capacity,compared with bulk counterparts.In this regard,I am going to talk about the preparation and electrochemical properties o...     

One-dimensional Nanostructured Materials From Organic Precursor

1 IntroductionOne-dimensional nanostructured materials, such as nanowires, nanobelts, nanotubes and nanocables have been attracting a great research interest in the last decade due to their superior electrical, optical, mechanical and thermal properties, and many methods have been explored to synthesis of the materials, e.g., arc discharge, laser ablation, chemical vapor deposition, thermal evaporation, sol-gel method, template method and so on. In this work, we present a novel and simple meth…     

A versatile biosensing platform coupling CRISPR-Cas12a and aptamers for detection of diverse analytes

Rapid and sensitive detection of various analytes is in high demand.Apart from its application in genome editing,CRISPR-Cas also shows promises in nucleic acid ...     

Nanostructured SnO2 photoanode-based dye-sensitized solar cells

This review focuses on recent developments in the nanostructured SnO2 photoanodes for dye-sensitized solar cells （DSSCs） applications. Carefully designed and fabricated nanostructured SnO2 films are advantageous for effective improvement in performance of DSSCs. Nano- crystals can offer a large surface area for dye adsorption; nanowires are able to provide a direct transfer pathway for the rapid collection of photogenerated electrons; the mes- oporous, monodisperse beads with a submicrometer-sized diameter ensure a large specific surface area for dye adsorption and simultaneously promote light scattering; the surface modification of SnO2 by other oxides may improve the photovoltage and photocurrent, hence resulting in the higher power conversion efficiency of SnO2-based DSSCs.     

纳米晶复合永磁铁氧体的双相交换耦合作用

采用sol-gel方法制备纳米晶复合SrFe12O19/γ-Fe2O3铁氧体.利用X射线衍射(XRD),透射电子显微镜(TEM)和振动样品(VSM)对纳米晶样品进行了研究.当焙烧温度介于600～800℃,样品存在SrFe12O19/γ-Fe2O3复相.在同样条件下,压成薄片的样品呈现了硬磁与软磁(SrFe12O19/γ-Fe2O3)的纳米复合相的交换耦合作用.对SrFe12O19/γ-Fe2O3的纳米复合材料的各向同性磁能积的增加和磁性交换耦合作用机制进行了研究.     

不同晶型的纳米二氧化钛的合成

对不同晶型纳米二氧化钛的合成方法和及其形貌控制作了简要综述．前驱体的种类和浓度，溶剂的极性，pH值，反应温度，添加剂等反应条件对所得纳米二氧化钛的晶型，颗粒大小及形貌有很大影响．通过选择不同种类的模板剂和控制反应条件可以制得具有不同晶型的介孔二氧化钛．     

纳米贝氏体钢中的位错密度测定

采用高分辨透射电子显微镜观察纳米贝氏体钢中铁素体的结构，并通过内耗方法测定了纳米贝氏体钢中铁素体的位错密度.结果表明，纳米贝氏体钢铁素体中分布着高密度的位错，其平均位错密度约为6.4×1015 m-2.     

二维磁性纳米结构材料的Monte Carlo模拟

运用Monte Carlo模拟方法，通过分折系统自旋序参数与温度的变化关系了解纳米结构材料磁性的特征．计算模拟结果表明，磁性纳米材料具有比同等大小和平均密度的单晶低的居里温度，且在相变过程中往往会出现一些亚稳态．研究结果提供了一种解析金属纳米结构材料特性的重要方法．     

面向空间应用的集成光电子技术

随着空间技术的蓬勃发展,微电子集成电路已不能满足空间信息系统对传输容量、通信速率、电磁兼容方面的要求.基于分立器件搭建的传统光电子系统在尺寸、重量、功耗和成本方面存在限制.集成光电子技术是解决上述瓶颈问题的关键途径,逐渐成为近年来的研究热点.本文从介绍铟磷、硅、氮化硅、薄膜铌酸锂等目前主要的集成光学材料的特性及研究基础出发,系统性地回顾了集成光电子技术在空间信息系统中的激光通信、微波光子、光学传感、自主导航与天文成像等应用方向的最新研究进展、技术瓶颈问题与发展思路.同时,对集成光电子器件在太空工作环境下的辐射效应和器件可靠性进行了介绍与分析.最后,对集成光电子技术在未来空间信息系统中的发展方向和应用前景做了分析与展望.     

Nanostructured LiMn2O4 and their composites as high-performance cathodes for lithium-ion batteries

Improvement of the energy density and power density of the lithium-ion batteries is urgently required with the rapid development of electric vehicles and portable electronic devices. The spinel LiMn2O4 is one of the most promising cathode materials due to its low cost, nontoxicity, and improved safety compared with commercial LiCoO2. Developing nanostructured electrode materials represents one of the most attractive strategies to dramatically enhance battery performance, such as capacity, rate capability and cycling life. Currently, extensive efforts have been devoted to developing nanostructured LiMn2O4 and LiMn2O4/carbon nanocomposites to further improve the rate capability of lithium-ion batteries for high-power applications. In this paper, recent progress in developing nanostructured LiMn2O4 and LiMn2O4/carbon nanocomposites is reviewed, and the benefits to the electrochemical performance of LiMn2O4-based cathodes by using these electrode materials are also discussed.