钒氧化物微/纳米空心球制备技术的研究

钒氧化物微/纳米空心球由于具有比表面积高、负载容量大、密度低等特性,在催化剂、传感器、锂离子电池、电池阴极材料等相关行业中有着广泛的应用前景和研究价值。本文综述了钒氧化物微/纳米空心球材料的制备方法,包括软模板剂法、硬模板剂法、水热合成法和溶剂热合成法等的研究进展,并对今后的研究方向进行了展望。     

微纳米碳空心球的合成研究及应用进展

微纳米碳空心球具有密度小、比表面积大、阻尼性能高、稳定性好和可填充中空结构等特性,在锂离子电池、催化、超级电容器、储氢、超导和阻尼等领域具有广阔的应用前景。本文结合近年来国内外的最新研究进展,综述了模板法、液相法和气相法等微纳米碳空心球的合成方法,评价了各种方法的特点,并讨论了微纳米碳空心球的应用研究进展。     

钙钛矿型氧化物的制备及其在固体氧化物燃料电池和金属-空气电池中的应用

本文对钙钛矿型氧化物的制备方法及其用于固体氧化物燃料电池(SOCFs)和金属-空气电池中的最新进展进行了较为全面的综述。制备钙钛矿型氧化物的方法有很多,包括盐分解法、固相法、共沉淀法、溶胶-凝胶法、水热法、反微乳法和模板法等。不同的制备方法可以得到各种形貌的钙钛矿型氧化物,如纳米立方体、纳米管、纳米棒、纳米片、纳米纤维和介孔结构。本文总结了这些制备方法的优点、缺点以及其适用的范围。作为一种重要的功能材料,钙钛矿型氧化物广泛应用于电极材料中。在SOCF中,重点介绍了阴极、阳极和电解质的研究现状,从电极材料的设计出发,比较了它们用于不同电极材料时的稳定性、电导率以及电催化活性,指出不足之处;在空气电极中,主要讨论了影响钙钛矿型氧化物氧的析出/还原催化活性和稳定性的因素。最后对钙钛矿型氧化物今后研究的方向和应用前景进行了预测。     

利用胶体碳球为模板制备SiO2、TiO2、SnO2空心球

介观尺度的氧化物空心球材料在许多领域都有着潜在的应用价值[1],因此近年来受到人们的广泛关注。其制备方法包括:模板法[2],声化学法[3],水热法[4]等。其中胶体粒子模板合成是制备氧化物空心球材料的一条最为有效的途径。常见的胶体粒子有金、银、CdS的纳米粒子,介观尺度的SiO     

纳米MoS2空心球的制备与表征

采用软模板法,通过添加十六烷基三甲基氯化铵(CTAC)作为模板剂,制得纳米MoS2空心球。采用SEM、TEM、XRD以及EDS等表征最终产物的形貌和化学成分,并基于CTAC和最终产物的FTIR光谱图,讨论了纳米MoS2空心球的形成机理。结果表明:产物为直径约30～100nm壁厚为10nm的空心球,结晶度较差,但可通过退火加以改善。在纳米MoS2空心球的形成过程中,CTAC不仅仅是作为模板剂和脚手架,还参与了化学反应生成中间体沉淀,并在此过程中,初步形成了核壳结构。     

空心球壳型V2O5的制备研究

无机空心微球含可容纳大量客体的中空部分,具有比表面积大、密度小、表面渗透能力强、稳定性好等特点,在化学、生物、材料科学和光电领域均有重要的应用,如控制释放胶囊(药物、颜料、化妆品、油墨)、催化剂及催化剂载体、分离材料、声学隔音材料以及电子学元件等。[1-3]空心球壳材料的制备方法通常有喷雾干燥法,乳液法[4],模板合成法[5]。近年来以胶体粒子为模板合成空心材料引起了人们的高度重视,其中聚苯乙烯微球(PSt)由于其形貌规整,粒径均一而被广泛用作形成空心结构的有机模板[6]。通过对锂离子电池正极材料的广泛研究,发现空心球壳型…     

水系锌离子电池钒基氧化物正极材料研究进展

近年来,钒基氧化物因为种类众多、理论比容量高和倍率性能优异等优点,被认为是一类具有潜在应用价值的水系锌离子电池正极材料。本文综述了V2O5、VO2等钒基氧化物材料的结构特点及其作为水系锌离子电池正极材料的最近研究进展。重点概述了当前钒基氧化物在锌离子电池中所面临的关键问题以及应对策略;最后,对钒基氧化物储锌材料的发展方向进行了展望。     

模板法合成核壳功能材料

模板法制备核壳功能材料是材料科学研究领域的一大热点引起了广泛的关注.本文结合本课题组在有机-无机核壳复合纳米粒子(空心球)领域的研究,较系统地评述了目前国内外利用模板法制备核壳粒子的研究进展,并概述了核壳纳米粒子(空心球)的发展前景和应用领域.     

无机微/纳空心球*

无机微/纳空心球材料以其独特的结构、优异的物理化学性能和广阔的应用前景,成为微/纳米材料研究和开发的一个热点领域之一。到目前为止,已研究开发出若干微/纳空心球材料的制备方法,并已制备出具有特殊物理和化学性能的空心球材料。其中,近年来的相关报道尤其多。本文主要回顾了近年来微/纳空心球材料研究和开发的最新进展,其中包括各种制备方法的原理、优缺点和适用范围,并展望了微/纳空心球材料的应用前景。     

五氧化二钒空心球制备及其作为镁二次电池正极材料

利用碳球作为模板,通过与异丙醇氧钒的溶剂热反应制备了五氧化二钒(V₂O₅)空心球。 采用扫描电子显微镜(SEM)和透射电子显微镜(TEM)等技术手段对V₂O₅空心球进行了表征。 实验结果表明,V₂O₅空心球的直径约为1.5 μm,壁厚约100 nm。 将V₂O₅空心球作为镁二次电池的正极,在0.2 C充放电条件下,材料的首次放电比容量达140 mA·h/g,经20次循环后容量为110 mA·h/g。     

单分散SnO2中空微纳米球的制备和性质

模板法是制备无机中空微纳米球的重要方法之一. 本文以苯乙烯为单体, 通过乳液聚合得到粒径约为620 nm的单分散聚苯乙烯(PS)微球. 以磺化后的聚苯乙烯(PSS)微球为模板, 利用阴阳离子静电吸附作用, 将PSS与前驱体SnSO₄中的Sn²⁺结合. 通过Sn²⁺在乙醇-水介质中的水解作用得到核-壳复合结构, 再经高温煅烧, 得到SnO₂中空微纳米球. 实验对前驱体的浓度、表面活性剂的用量、反应时间及模板选择等方面做了研究,通过扫描电镜(SEM)、X 射线衍射(XRD)、红外(IR) 光谱、热重分析(TGA)、H₂ 程序升温还原(H₂-TPR)、Brunauer-Emmett-Teller (BET)比表面积等技术深入探究SnO₂中空微纳米球的结构, 并对比中空SnO₂与实心粒子的氧化还原特性. BET和H₂-TPR显示将SnO₂制备成微纳米空心球后其比表面积增大, 表面氧空位明显增多, 氧化活性明显提高. 从IR 及XRD推断核-壳结构形成机理, 进而优化出简单合理的实验方案, 获得表面光滑、结构致密, 包覆厚度可控的SnO₂中空微纳米球.     

Template Effect of Hydrophobically Associating Polymers on theConstruction of Cuprous Oxide Micro Structure

To determine the template effect of hydrophobically associating copolymers(HACPs) on the morphology of nano/micro structures, six HACPs were synthesized and used as templates to biomimetically synthesize cuprous oxide(Cu₂O), an important semiconductor. This experiment showed a clear relationship between the associating state of the HACP molecules and the morphology of the Cu₂O particles. Cu₂O hollow spheres were preferentially prepared when the HACP molecules were in an intramolecular associating state. Furthermore, a Cu₂O hexapod was easily obtained when the HACP molecules were in an intermolecular associating state. The morphologies of the Cu₂O crystals prepared in the presence of the HACPs also confirmed this result.     

Chemical‐Template Synthesis of Micro/Nanoscale Magnesium Silicate Hollow Spheres for Waste‐Water Treatment

Micro/nanoscale magnesium silicate hollow spheres were synthesized by using silica colloidal spheres as a chemical template in one pot. The hollow spherical structure, consisting of well‐separated nanoscale units, was microscale as a whole and could be easily handled in solution. The as‐synthesized magnesium silicate hollow spheres with large specific surface area showed availability for the removal of organic and heavy‐metal ions efficiently from waste water. Importantly, the micro/nanoscale magnesium silicate hollow spheres that had adsorbed organic pollutants could be regenerated by calcination and used repeatedly in pollutant removal. Magnesium silicate hollow spheres synthesized by a scaled‐up chemical template method may have potential applications in removing cationic dyes and heavy‐metal ions from waste water.     

Low‐Temperature Facile Template Synthesis of Crystalline Inorganic Composite Hollow Spheres

This report presents a facile approach for the low‐temperature synthesis of crystalline inorganic‐oxide composite hollow spheres by employing the bulk controlled synthesis of inorganic‐oxide nanocrystals with polymer spheres as templates. The sulfonated polystyrene gel layer can adsorb the target precursor and induce inorganic nanocrystals to grow on the template in situ. The crystalline phase and morphology of the composite shell is tunable. By simply adjusting the acidity of the titania sol, crystalline titania composite hollow spheres with tunable crystalline phases of anatase, rutile, or a mixture of both were achieved. The approach is general and has been extended to synthesize the representative perovskite oxide (barium and strontium titanate) composite hollow spheres. The traditional thermal treatment for crystallite transformation is not required, thus intact shells can be guaranteed. The combination of oxide properties such as high refractive index, high dielectric constant, and catalytic ability with the cavity of the hollow spheres is promising for applications such as opacifiers, photonic crystals, high‐κ‐gate dielectrics, and photocatalysis.     

Metal oxide and sulfide hollow spheres: layer-by-layer synthesis and their application in lithium-ion battery

A novel layer-by-layer approach has been developed to synthesize polycrystalline SnO(2) hollow spheres with tunable shell thickness and size using SiO(2) spheres as a template. The surface of the SiO(2) spheres has been first modified by the polyelectrolyte, and subsequently, the compact SnO(2) layer has deposited on the surface of the SiO(2) spheres through a redox reaction because of the electrostatic attraction between the charged species. After HF etching treatment, the uniform SnO(2) hollow spheres have been obtained. The approach presented herein has been extended to synthesize other metal oxide and sulfide hollow spheres such as In(2)O(3) and ZnS. Moreover, the as-synthesized SnO(2) hollow spheres have been applied in lithium-ion battery and show improved performance compared with SnO(2) nanoparticles. The high surface area and stable hollow structure of the SnO(2) hollow spheres may be responsible for the improved performance.     

Self‐Templated Formation of Uniform NiCo2O4 Hollow Spheres with Complex Interior Structures for Lithium‐Ion Batteries and Supercapacitors

Despite the significant advancement in preparing metal oxide hollow structures, most approaches rely on template‐based multistep procedures for tailoring the interior structure. In this work, we develop a new generally applicable strategy toward the synthesis of mixed‐metal‐oxide complex hollow spheres. Starting with metal glycerate solid spheres, we show that subsequent thermal annealing in air leads to the formation of complex hollow spheres of the resulting metal oxide. We demonstrate the concept by synthesizing highly uniform NiCo₂O₄ hollow spheres with a complex interior structure. With the small primary building nanoparticles, high structural integrity, complex interior architectures, and enlarged surface area, these unique NiCo₂O₄ hollow spheres exhibit superior electrochemical performances as advanced electrode materials for both lithium‐ion batteries and supercapacitors. This approach can be an efficient self‐templated strategy for the preparation of mixed‐metal‐oxide hollow spheres with complex interior structures and functionalities.     

Size effect on thermodynamic properties of CaMoO4 micro/nano materials and reaction systems

CaMoO₄ micro/nano hollow spheres with three different sizes were prepared via a reverse-microemulsion route at room temperature. Through designing a novel thermochemical cycle, the relationship between thermodynamic properties of nano CaMoO₄ and bulk CaMoO₄ was built. Combined with in situ microcalorimetry, change regularities for the thermodynamic properties of the prepared CaMoO₄ micro/nano materials and reaction systems were obtained. The results reveal that size effect has significant influence on thermodynamic properties of micro/nano materials and reaction systems. Along with the size decreasing, the standard molar enthalpy, standard molar Gibbs free energy and standard molar entropy of reaction of micro/nano reaction systems decreased, but the standard molar enthalpy of formation, standard molar Gibbs free energy of formation and standard molar entropy of micro/nano materials increased.     

基于pH响应型微凝胶模板的二氧化锰空心球制备

以pH响应型微凝胶为模板制备出了二氧化锰空心球材料,并利用XRD、TGA、SEM、FT—IR和TEM等手段对其进行了表征．结果表明,通过调节KMn04的用量可以有效控制二氧化锰空心球的球壳厚度．对洗脱后上层清夜中的pH响应型微凝胶进一步研究发现,部分微凝胶呈现出非可逆的膨胀一收缩转变,这一现象主要是由于其内部的交联程度不高造成的．在对表征结果进行分析后提出了空心球结构的形成机理．     

Fabrication of hollow spheres of metal oxide using fructose-derived carbonaceous spheres as sacrificial templates

In this report, fructose-derived carbonaceous spheres were utilized as sacrificial templates for the fabrication of metal oxide hollow spheres (MOHSs) by a facile hydrothermal approach. Hollow spheres of a series of crystalline metal oxides (α-Fe₂O₃, Cr₂O₃, Co₃O₄, NiO, and ZnO) have been fabricated, utilizing the metal chloride as the oxide precursors. Heating of an aqueous solution of the metal chloride and fructose to moderate temperature in an autoclave affords a spherical composite consisting of a metal precursor shell sheathing a carbonaceous core. Subsequent removal of the interior carbonaceous cores by thermal treatment through oxidation in air produces free-standing crystalline oxides hollow spheres. The MOHSs were characterized by means of SEM, TEM, XRD, IR spectroscopy, energy dispersive X-ray (EDX) and sorption measurements. The results show convincingly that using fructose as a sacrificial template after application of a hydrothermal synthesis route could be a favourable sacrificial template for the fabrication of various MOHSs.