【作者】 王定胜；

【导师】 李亚栋；

【作者基本信息】 清华大学 ， 化学， 2009， 博士

【摘要】 探索纳米材料的可控制备方法以及实现其规模化应用已成为该领域关键课题之一。本论文围绕氧化物和硫化物纳米材料的合成和应用展开研究。在合成方面,探索实验室批量合成方法,努力突破困扰纳米晶宏量制备的技术瓶颈,为实现其规模化制备奠定基础。在应用方面,探索氧化物和硫化物纳米材料在催化和锂离子电池等重要领域的用途。研究纳米材料结构、形貌和尺寸等参数与其性能之间的关系,为解决纳米材料在相关领域中的应用难题并最终实现纳米材料的工业化应用提供实验基础。发展了一种基于金属硝酸盐热分解反应简易制备金属及氧化物纳米晶的方法。设计以十八胺同时作为溶剂和表面活性剂的单一组分体系,研究了不同类型金属硝酸盐(硝酸银、过渡金属硝酸盐及稀土硝酸盐)在十八胺中的热解规律,实现了单分散纳米银颗粒及系列过渡金属氧化物(Mn3O4、CoO、NiO等)和稀土氧化物(CeO2、La2O3、Y2O3等)纳米材料的可控制备。建立了一种简易制备硫/硒化物半导体纳米晶的普适方法。在十八胺体系中,以廉价易得的无机盐类和硫粉或硒粉为原料合成了系列半导体纳米晶(Ag2S、Bi2S3、CdS、MnS、Ag2Se、CdSe、AgInS2、CuInS2、AgInSe2等),通过控制实验参数实现了对纳米晶形貌和尺寸的有效调控。发展出一种以单分散纳米晶为构建基元通过组装的方法制备介孔结构材料的通用策略,实现了金属(Ag)、系列氧化物(CoO、NiO、MnO等)和硫/硒化物(Ag2S、Ag2Se)介孔材料的制备。围绕所制备的氧化物和硫化物纳米材料,开展了其在催化和锂离子电池等重要领域的应用基础研究。通过研究介孔氧化物(CoO、NiO、MnO等)、复合氧化物(LiCoO2、LiNiO2、LiMn2O4等)以及硫化物(Bi2S3纳米管)作为锂离子电池正极材料的应用,提出了介孔电极的概念以及锂离子嵌入/脱嵌动力学过程的晶面相关性概念;以NiO纳米催化剂以及CuO/MgO和Au/La2O3负载型纳米催化剂为研究体系,探索了纳米材料结构、形貌和尺寸等参数与其催化活性之间的关系,证实了纳米晶催化剂性能的晶面相关性概念。更多还原

【Abstract】 In the past decades, a series of developments have been made in nanomaterials. Nowadays, exploiting more convenient, economical and large-scale synthetic strategies and achieving industrial applications of nanostructural materials are two key directions in nano field. This dissertation focuses on synthesis and applications of metal oxide/sulfide nanomaterials. On one hand, in order to overcome technical bottle-neck of nanosynthesis and achieve large-scale preparation of high quality nanocrystals, many efforts have been made to exploit new synthetic strategies. On the other hand, in order to achieve industrial applications of metal oxide/sulfide nanomaterials in many important areas such as catalysis and Li-ion batteries, valuable investigations have been carried out on the relationship between crystal structure, size and shape of nanomaterials and their properties.A simple synthetic method for metal and oxide nanocrystals has been developed based on thermal decomposition of metal nitrates. A system composed of a single component of octadecylamine (ODA) which served as both the solvent and the surfactant was designed and the decomposed regularities of three different kinds of metal nitrates in this system were investigated including silver nitrate, transition metal nitrates (manganese nitrate, cobalt nitrate, nickel nitrate, etc.) and rare-earth nitrates (cerium nitrate, lanthanum nitrate, yttrium nitrate, etc.). Controllable synthesis of monodisperse Ag nanoparticles and a series of transition metal oxide (Mn3O4, CoO, NiO, etc.) and rare-earth oxide (CeO2, La2O3, Y2O3, etc.) nanocrystals was achieved.A facile one-pot synthetic procedure for chalcogenide semiconductor nanocrystals (Ag2S, Bi2S3, CdS, MnS, Ag2Se, CdSe, etc.) has been developed. Nontoxic inorganic salts and inexpensive sulfur or selenium powder were employed as reagents while ODA was used as both the solvent and the surfactant. Control of shape and size of nanocrystals was achieved by adjusting the reaction conditions and semiconductors with one-dimensional (1D) nanostructures were obtained such as Ag2S nanowires and Bi2S3 nanotubes. This strategy was also suitable for preparation of high qualityⅠ-Ⅲ-Ⅵ2 ternary semiconductors (AgInS2, CuInS2, AgInSe2, etc.).The assembly behavior of various kinds of monodisperse nanocrystals obtained via the above mentioned synthetic methods was investigated and a general strategy for mesoporous materials has been developed, namely, using monodisperse nanocrystals as uniform building blocks to construct mesoporous structures. The preparation of mesostructural materials including metal (Ag), metal oxides (CoO, NiO, MnO, etc.), and metal sulfides/selenides (Ag2S, Ag2Se) was achieved by this strategy.The applications of as-synthesized metal oxide/sulfide nanocrystals in many important areas such as catalysis and Li-ion batteries have been investigated. On one hand, the advantages of mesoporous metal oxides (CoO, NiO, MnO, etc.), mixed oxides (LiCoO2, LiNiO2, LiMn2O4, etc.), and metal sulfides (Bi2S3 nanotubes) as cathodes in Li-ion batteries were discussed. On the other hand, the influence of crystal morphology on catalytic performance of nanocatalysts (NiO) and supported nanocatalysts (CuO/MgO, Au/La2O3) was studied.更多还原