利用软模板法合成中空纳米结构的研究进展

中空纳米材料具有高负载、低密度、和比表面积大等特点,有着广泛应用。软模板合成中空纳米结构具有简单易行和结构可控等优点。目前,采用最多的软模板主要有微乳液、胶束/囊泡模板和气泡软模板,通过静电吸附、氢键和界面反应等方法使纳米粒子沉积在模板表面便可得到中空结构。本文总结并展望了利用软模板法合成中空纳米结构的研究进展。     

中空贵金属纳米材料氧还原催化的研究进展（英文）

中空纳米结构具有比表面积大、传质可控和活性位点明确等优势,其结构设计与电催化应用在能源转化与储存领域引起了广泛关注.特别是中空贵金属纳米材料用于氧还原催化时,中空内腔引入到贵金属纳米结构,不仅暴露更多的活性位点,还能减少贵金属的用量,这将为贵金属催化剂的大规模应用提供一个理想的研发平台.本文综合评述了近年来中空贵金属的合成策略及其氧还原催化应用.首先,回顾了中空贵金属在氧还原催化剂研制中的优势与意义;然后,介绍了近期关于中空贵金属的制备策略(硬模板法、软模板法、自模板和无模板法等)及其优势;最后,分析了中空贵金属在氧还原领域所面临的挑战,并对其设计进行了展望.     

金属纳米结构的氧化刻蚀调控与催化性能优化

金属纳米结构的可控合成,对其性能优化和高效应用至为关键．氧化刻蚀作为金属纳米晶可控合成中的新兴有效调控手段之一,受到越来越多的关注．本文以本课题组近期的研究工作为例,说明了氧化刻蚀对金属纳米晶的形貌、尺寸、结构及组成等合成参数的有效调控作用．由此总结认为,在金属纳米晶可控合成的一般过程,尤其是成核和生长过程中,氧化刻蚀的本质是有效调控“两个速率”和“两个力学”,即减缓原子的生成速率与晶种的形成速率、选择性接受反应热力学和反应动力学的控制作用．我们将通过氧化刻蚀法调控合成得到的具有独特结构的Pd,Pt纳米晶,用于氧活化和电催化这两个重要的催化体系,获得了理想的催化结果,表明氧化刻蚀在金属纳米晶的功能改性和应用拓展方面,具有令人称奇的广阔应用前景．     

聚合物基模板制备中空介孔材料

中空介孔材料,尤其是硅基和碳基中空介孔材料,由于其孔道结构丰富、孔径可调、高比表面积、可容纳客体分子、良好的热稳定性和化学稳定性等特点已被广泛应用于催化、能量储存等众多领域。模板法是目前为止制备中空介孔结构最有效的方法之一,其最大特点是可以通过对模板的调控来实现对中空介孔结构的控制。聚合物基模板种类繁多,主要包括嵌段共聚物、聚合物乳胶粒、天然/合成生物大分子及复杂结构高分子等;与传统的表面活性剂/无机氧化物模板相比,其自组装形态更加丰富,结构更易进行功能化修饰。同时,以聚合物为模板的合成反应条件更加温和可控,更有利于合成形态各异、功能丰富的中空介孔材料。本文综述了近年来不同聚合物基模板合成中空介孔材料的研究进展,并着重介绍了贵金属粒子负载的中空介孔材料在催化载体领域的应用;同时,指出了当前阻碍中空介孔材料发展的问题,并对其在催化领域的应用前景进行了展望。     

多策略可控合成原子精度合金纳米团簇

合金纳米团簇作为一类新兴的多功能纳米材料已被广泛用于催化、光学传感以及生物医学成像等研究领域,而纳米团簇的可控合成和结构特征是调节纳米团簇性质并对其进一步利用的基础。尽管当前有关金属纳米团簇可控合成和结构特征的研究主要集中在单金属纳米团簇中,但有关合金纳米团簇原子精度的可控合成也取得了显著的进展。本文综述了配体保护的合金金属纳米团簇原子精度可控合成策略,包括一步合成法、金属交换、配体交换、化学刻蚀、簇间反应、原位两相配体交换以及最新的表面模体交换反应,并对相关合成策略的优缺点进行了详细的讨论和阐述。     

自模板法制备介孔空心无机微/纳米结构

与传统的软、 硬模板法相比, 近期发展的自模板法具有反应步骤少和无需额外模板等众多优点, 同时, 介孔空心无机微/纳米结构在催化、 能源和医药等领域的巨大应用前景也使其制备方法备受关注. 本文根据不同的反应机理, 从Ostwald熟化、 表面保护刻蚀、 柯肯达尔效应和电偶置换反应4个方面分别综述了自模板法的最新研究进展和应用现状, 并展望了自模板法的研究与应用前景.     

多策略可控合成原子精度合金纳米团簇（英文）

合金纳米团簇作为一类新兴的多功能纳米材料已被广泛用于催化、光学传感以及生物医学成像等研究领域,而纳米团簇的可控合成和结构特征是调节纳米团簇性质并对其进一步利用的基础。尽管当前有关金属纳米团簇可控合成和结构特征的研究主要集中在单金属纳米团簇中,但有关合金纳米团簇原子精度的可控合成也取得了显著的进展。本文综述了配体保护的合金金属纳米团簇原子精度可控合成策略,包括一步合成法、金属交换、配体交换、化学刻蚀、簇间反应、原位两相配体交换以及最新的表面模体交换反应,并对相关合成策略的优缺点进行了详细的讨论和阐述。     

大孔道介孔氧化硅/碳基纳米材料的设计合成与应用

由于具有较大的孔道尺寸、 丰富的化学组成以及广阔的应用前景, 大孔道介孔纳米材料近年来引起了科研工作者的广泛关注. 分别利用复合胶束和无机纳米晶作为结构基元进行可控自组装的软模板法和硬模板法是合成这类大孔道介孔纳米材料最有效的两类方法. 本文总结了一系列基于不同类型软模板或硬模板共组装形成大孔道介孔纳米材料的合成方法和策略, 并讨论了所获得的大孔道介孔纳米材料在催化、 能量转换与存储以及生物医学中的应用. 最后, 对利用新型嵌段聚合物或复杂结构纳米晶合成大孔道介孔纳米材料的前景和挑战进行了展望.     

柔软的球状和长方体状氧化硅中空结构的制备研究

采用自组装形成的芘纳米结构作为模板,成功地制备了柔软的球状和长方体状氧化硅中空结构.当不同量的芘在十六烷基三甲基溴化铵(CTAB)溶液中自组装时,产生的自组装结构展现出明显的从球状到长方体状的形貌变化.这些结构被用作氧化硅前驱体溶胶-凝胶反应的模板,获得了球状和长方体状氧化硅/芘复合结构.通过乙醇除去模板后,生成了柔软的球状(直径约为400nm)和长方体状(长为0.5—2.5μm)的氧化硅中空结构.这些结果展现了采用有机纳米结构作为模板来合成无机中空结构的优势:合成简便、结构多样以及结构形貌的灵活可控.     

单分散中空介孔结构的盐模板合成及形貌调控

中空介孔结构因具有丰富的内部空间以及多孔渗透性外壳等优势,在催化、能源储存与转化及生物医药等领域得到了广泛应用.然而,目前仍然缺少高效、简便且绿色的合成中空介孔结构的方法.本文以柠檬酸钠胶体颗粒作为模板,通过十六烷基三甲基溴化氨(Cetyltrimethylammonium bromide, CTAB)胶束与正硅酸四乙酯(Tetraethyl orthosilicate, TEOS)的水解低聚物在胶体颗粒表面进行界面共组装,直接生长介孔二氧化硅壳层;然后通过简便的醇洗和水洗分别除去CTAB胶束和柠檬酸钠胶体颗粒后,得到中空介孔结构.进一步研究表明,负电荷的柠檬酸钠胶体颗粒与CTAB胶束之间的静电相互作用是诱导氧化硅低聚物在颗粒表面进行交联组装的关键.基于此,通过控制生长时间实现了对中空介孔结构形貌和壳层厚度的精确调控.所得中空介孔二氧化硅纳米球可以显著增强物质的扩散传输,是理想的催化剂载体,负载金纳米颗粒后可以高效催化4-硝基苯酚的还原反应.研究结果为中空介孔材料的绿色简便合成提供了思路.     

When Mesoporous Silica Meets the Alkaline Polyelectrolyte: A Controllable Synthesis of Functional and Hollow Nanostructures with a Porous Shell

An efficient and environment friendly surface‐protected etching method by using mesoporous silica as a template and alkaline polyelectrolyte as both the protecting and etching agent was developed to prepare a SiO₂ nanotube with a porous shell. The polyelectrolytes attached to the template not only create a localized alkaline environment, but also effectively protect the silica surface, whereas the mesopore channels accelerate the diffusion of etchant throughout the template, all of which facilitate the formation of hollow structures in a fully controllable way. By tuning the etching power and protecting ability of the polyelectrolyte, the rigidity and porosity of products can be precisely manipulated. It is inspiring that various alkaline polyelectrolytes including polypeptide and dextran derivative can be used for the etching process, so that the porous and hollow nanostructures are born with positively charged and biocompatible surface as well as abundant amino groups for further coupling, which make them potential capsules for drug delivery and probes for imaging and detection. The protective etching process can also be extended to the preparation of yolk‐shell super structures with functional cores, or porous nanoparticle assemblies with their individual characteristics maintained.     

Recent Development on Controlled Synthesis of Metal Sulfides Hollow Nanostructures via Hard Template Engaged Strategy: A Mini‐Review

In this mini‐review, we highlighted the recent progresses in the controlled synthesis of metal sulfides hollow nanostructures via hard template technique. After a brief introduction about the formation mechanism of the inorganic hollow nanostructures via hard template technique, the discussions primarily focused on the emerging development of metal sulfides hollow nanostructures. Various synthetic strategies were summarized concerning the use of the hard template engaged strategies to fabricate various metal sulfides hollow nanostructures, such as hydrothermal method, solvothermal method, ion‐exchange, sulfidation or calcination etc. Finally, the perspectives and summaries have been presented to demonstrate that a facile synthetic technique would be widely used to fabricate metal sulfides hollow nanostructures with multi‐shells and components.     

Yolk/shell nanoparticles: new platforms for nanoreactors, drug delivery and lithium-ion batteries

Yolk/shell or 'rattle-typed' nanomaterials with nanoparticle cores inside hollow shells are interesting among the complex hollow nanostructures. Yolk/shell nanoparticles (YSNs) are promising functional nanomaterials for a variety of applications such as catalysis, delivery, lithium-ion batteries and biosensors due to their tailorability and functionality in both the cores and hollow shells. This feature article provides an overview of advances in this exciting area of YSNs, covering systematic synthesis approaches and key promising applications based on the literature and our own recent work. We present some strategies for the synthesis of YSNs with controllable sizes, compositions, geometries, structures and functionalities. Applications of these new materials in a wide range of potential areas are discussed including nanoreactors, biomedicine and lithium-ion batteries. Promising future directions of this active research field are also highlighted.     

以氨基酸为晶体生长控制剂合成多级纳米结构的硫化铟空心微球

以水热方法制备具有多级纳米结构的In2S3空心微球. 通过对不同反应时间产物的跟踪表征, 证明微球中空结构的形成归因于Ostwald ripening机理. 空心微球的壳层由In2S3的纳米粒子或纳米片组成, In2S3空心球的紫外可见光谱蓝移以及荧光光谱在约385 nm的强发射和364 nm的弱发射, 均显示了纳米尺度In2S3晶体的量子局限效应. 以不同的氨基酸作为晶体生长修饰剂, 可以选择性地制备不同表面形貌的In2S3空心微球, 显示了氨基酸的不同功能团在In2S3晶体生长过程中对表面形貌的控制作用.     

Bottom-up synthesis of gold octahedra with tailorable hollow features

Gold octahedra with hollow features have been synthesized in high yield via the controlled overgrowth of preformed concave cube seeds. This Ag(+)-assisted, seed-mediated synthesis allows for the average edge length of the octahedra and the size of the hollow features to be independently controlled. We propose that a high concentration of Ag(+) stabilizes the {111} facets of the octahedra through underpotential deposition while the rate of Au(+) reduction controls the dimensions of the hollow features. This synthesis represents a highly controllable bottom-up approach for the preparation of hollow gold nanostructures.     

Silver Hollow Microspheres: Large-scale Synthesis, Characterization and Electromagnetic Shielding Property

A facile and large-scale synthesis method to fabricate silver hollow microspheres with controllable morphologies and shell thickness is described using low-cost glass microspheres as templates. The method mainly involves two steps of the preparation of silver-coated glass microsphere core-shell particles by a controllable liquid reduced reaction of Ag[(NH3)2]+ solution, which only produces silver nanoparticles anchored on the surface of the thiolated glass microsphere templates, and the removal of glass microspheres by wet chemical etching with HF solution. The products are well characterized by field emitted scanning electron microscopy (SEM), transmitted electron microscopy (TEM), X-ray photoelectron spectra (XPS), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) etc. The as-prepared core-shell particles and hollow particles have even and compact silver shells. The electromagnetic shielding coatings based on the silver hollow microspheres are demonstrated to have high conductivity, excellent shielding effectiveness and long durability, suggesting that the silver hollow microspheres obtained here are a novel light-weight electromagnetic shielding filler and will have extensive applications in the electromagnetic compatibility fields.     

One-step synthesis of SnO2 and TiO2 hollow nanostructures with various shapes and their enhanced lithium storage properties

A versatile one-step method for the general synthesis of metal oxide hollow nanostructures is demonstrated. This method involves the controlled deposition of metal oxides on shaped α-Fe(2)O(3) crystals which are simultaneously dissolved. A variety of uniform SnO(2) hollow nanostructures, such as nanococoons, nanoboxes, hollow nanorings, and nanospheres, can be readily generated. The method is also applicable to the synthesis of shaped TiO(2) hollow nanostructures. As a demonstration of the potential applications of these hollow nanostructures, the lithium storage capability of SnO(2) hollow structures is investigated. The results show that such derived SnO(2) hollow structures exhibit stable capacity retention of 600-700?mA h g(-1) for 50?cycles at a 0.2?C rate and good rate capability at 0.5-1?C, perhaps benefiting from the unique structural characteristics.     

One‐Step Synthesis of SnO2 and TiO2 Hollow Nanostructures with Various Shapes and Their Enhanced Lithium Storage Properties

A versatile one‐step method for the general synthesis of metal oxide hollow nanostructures is demonstrated. This method involves the controlled deposition of metal oxides on shaped α‐Fe₂O₃ crystals which are simultaneously dissolved. A variety of uniform SnO₂ hollow nanostructures, such as nanococoons, nanoboxes, hollow nanorings, and nanospheres, can be readily generated. The method is also applicable to the synthesis of shaped TiO₂ hollow nanostructures. As a demonstration of the potential applications of these hollow nanostructures, the lithium storage capability of SnO₂ hollow structures is investigated. The results show that such derived SnO₂ hollow structures exhibit stable capacity retention of 600–700 mAh g^?1 for 50 cycles at a 0.2 C rate and good rate capability at 0.5–1 C, perhaps benefiting from the unique structural characteristics.