Preparation, Characterization and Application of metal Oxide (ZnO and SnO2) semiconducting nanomaterials

众所周知，许多金属氧化物是具有特殊物理化学性能的功能材料，在催化剂、微电子器件、能量储存与转化等诸多领域有着广泛的应用。氧化锌（ZnO）和氧化锡（SnO2）以其优异的光电性质以及高灵敏的气敏性质一直被认为是金属氧化物中最有应用前景的两种功能材料，它们都是典型的n型宽禁带直接半导体，其室温禁带宽度分别为3.37eV和3.65eV。最近几年，科研人员投入了相当大的精力对各种类型ZnO和SnO2纳米材料的合成、表征以及它们在纳米器件领域中的应用进行了深入研究。鉴于它们在未来功能器件中的重要性，ZnO和SnO2这两种金属氧化物被确定为本人博士论文期间的研究内容。 本博士论文将主要围绕三大研究方向进行...As is well known, many metal oxides are functional materials with excellent physical and chemical properties, and widely applied in many fields including catalysts, microelectronic devices, energy storage and conversion. Among these metal oxides, ZnO and SnO2 have been considered as the most promising functional materials due to highly sensitive gas sensing property and excellent photoelectrical p...学位：理学博士院系专业：化学化工学院化学系_无机化学学号：B20032500

热力学在无机化学“四大平衡”教学中的应用

利用化学反应吉布斯自由能变化?_rG_m~?来计算无机化学\"四大平衡\"的平衡常数,解释诸如沉淀-溶解平衡教学中为什么要求微溶强电解质等问题,并从化学反应等温式类推了电极反应的等温式,推导了复杂电极的标准电极电势与其简单电极的标准电极电势之间的关系,拓展了热力学在现行基础化学教学上的应用范围。国家基础科学人才培养基金(J1310024

Ag2S nanocaps from AgBr nanoplates: Template symmetry breaking synthesis induced by the polar surfaces

HK-RGC General Research Funds [2 HKUST 605710, 604809]; Hong Kong Scholar Program [XJ2011031]; program for New Century Excellent Talents in University [NCET-11-0294]Hexagonal cap-like nanocrystals (nanocaps) of Ag2S are synthesized through a simple ion-exchange reaction by using polar {111} faceted, hexagonally shaped AgBr nanoplates as sacrificial templates, in which the bottom/top surfaces presented distinct reactivity with S2- ions due to their different atomic compositions and arrangements. Surprisingly, the Ag2S nanocaps presented strong surface-enhanced Raman scattering activity

Surface structure-controlled synthesis of nanocrystals through supersaturation dependent growth strategy

纳米晶体很多重要的物理化学性质与其表面结构密切相关, 纳米晶的表面结构调控及相关理论研究是前沿和热点领域.; 本评述总结了非平衡态过饱和条件下纳米晶体生长热力学相关理论及其在离子晶体、分子晶体、贵金属、氧化物、金属有机框架等5类纳米晶体表面结构控制中的应; 用. 从热力学推导出的"类"Thomson-Gibbs方程可以发现, 晶体裸露晶面的表面能与其生长过程生长基元的过饱和度成正比.; 该理论揭示了过饱和度在纳米晶体表面结构控制中的重要作用, 为合理设计合成具有特定表面结构的纳米晶提供了有效指导.Many physical and chemical properties of nanocrystals are closely; related to their surface structures. Studies on the surface structure; control of nanocrystals and related theories are hot and frontier; research topics recently. In this review, we introduce the; supersaturation control strategy and its application in the surface; structure control of nanocrystals ranging from ionic, molecular,; metallic, metal oxide, to metal-organic frameworks crystals. Deduced; from thermodynamics, it can be found that the surface energy of; nanocrystals is directly proportional to the supersaturation of growth; units. The relationship between supersaturation and surface energy; provides an important theoretical basis for the controlled synthesis of; nanocrystals with specific surface structure.国家重点基础研究发展计划; 国家自然科学基金项目; 中央高校基本科研业务费专项资金资助; 中国博士后科学基

Electrical and photocatalytic properties of Na2Ti6O13 nanobelts prepared by molten salt synthesis

Single-crystalline Na2Ti6O13 nanobelts were prepared on large-scale by molten salt synthesis at 825 degrees C for 3 h. The obtained nanobelts have typical width of less than 200 nm and thickness of 10-30 nm, and length up to 10 mm. The growth direction of the nanobelts was determined to be along [ 0 1 0]. Electrical transport property of an individual nanobelt was measured at room temperature and ambient atmosphere, and results showed that the nanobelts are semiconductor. Na2Ti6O13 nanobelts exhibited good photocatalytic efficiency for the degradation of RhB under UV irradiation. (C) 2008 Elsevier B. V. All rights reserved

高指数晶面裸露的贵金属纳米晶体的合成

由于在高指数晶面上存在高密度的台阶位、扭结位原子等,高指数晶面裸露的贵金属纳米晶体一般表现出优越的物理化学性能,在催化、电化学等方面都有很重要的应用前景.近年来,研究人员围绕高指数晶面的制备进行了大量的工作并取得了一定进展.本文重点从合成制备方法的角度出发,结合本课题组的相关研究,系统总结了现有的有关制备高指数晶面裸露的贵金属纳米晶体的一些最新研究成果.从电化学方法、"帽"式试剂保护法、欠电位沉积原子层保护法、动力学调控、氧化刻蚀溶解再生长法以及模板法等几个方面对现有的高指数晶面裸露的贵金属纳米晶体的制备进行了总结

Formaldehyde-assisted synthesis of ultrathin Rh nanosheets for applications in CO oxidation

National Basic Research Program of China [2011CBA00508]; National Natural Science Foundation of China [21171142]; program for New Century Excellent Talents in University [NCET-11-0294]; Fundamental Research Funds for the Central UniversitiesUltrathin Rh nanosheets with a thickness of approximately 1 nm were synthesized via a simple surfactant-free hydrothermal route, using Rh(II) acetylacetonate as the precursor and formaldehyde as the shape controller. CO and H-2 originating from the formaldehyde decomposition played key roles in the formation of ultrathin Rh nanosheets

Mesoporous Mn3O4-CoO core-shell spheres wrapped by carbon nanotubes: a high performance catalyst for the oxygen reduction reaction and CO oxidation

National Natural Science Foundation of China [51173055]; Fundamental Research Funds for the Central Universities [2013QN158]; Research Fund for the Doctoral Program of Higher Education of China [20130142120024]The controllable synthesis of transition metal oxide nanomaterials has attracted considerable attention for the replacement of the current precious metal catalysts. Herein, we have developed a facile method to successfully synthesize Mn3O4-CoO core-shell mesoporous spheres, which are wrapped by carbon nanotubes (CNT), and investigated the catalytic activity for the oxygen reduction reaction (ORR) and CO oxidation for the first time. The ORR process on the Mn3O4-CoO/CNT catalysts was via a complete oxygen reduction process (4e(-)), and the catalytic activity was far better than for the Mn3O4/CNT and CoO/CNT catalysts. The durability even out-performed the commercial Pt/C catalysts. As compared with the Mn3O4/CNT and CoO/CNT catalysts, the Mn3O4-CoO/CNT catalysts also exhibited better catalytic activity for CO oxidation. The initial and complete conversion temperatures for the Mn3O4-CoO/CNT catalysts can decrease to 30 and 120 degrees C, respectively. The good catalytic activity for the ORR and CO oxidation is due to the high specific surface area (138.9 m2 g(-1)) provided which gives many catalytically active sites, mesoporous structure (15 to 120 nm) favoured for molecule accessibility to the active surface of the nanocrystals and mass transport, and the synergistic catalytic effect of Mn3O4 and CoO catalytically active sites

海马学习记忆中的作用

正近十年来,关干学习记忆的神经机制问题中,大量的研究涉及海马与记忆的关系,大多数材料表明,海马与记忆的早期阶段有关,或与探究反射有关。因而损毁海马导致条件反射难于建立和巩固,探究反射消退(习惯化)不能。但是对于海马作用的机理尚存在不同的理解。近年来,我们就海马与学习记忆的关系进行了多方面的探讨：观察了损毁和电刺激海马对学习记忆的影响；动物在学习时海马,皮层的电活动变化,并与兄弟单位协作观察了海马单个神经元的自发和诱发活动的特点。现在上述的材材进行简要总结。中国心理学

Intense and wavelength-tunable photoluminescence from surface functionalized MgO nanocrystal clusters

We report fancy brilliant photoluminescence (PL) from surface functionalized MgO nanocrystal clusters (NCs). Single-crystal-like MgO NCs were prepared by a simple one-pot pyrolysis method in the mixed organic solvent of octylamine (OTA) and oleic acid (OA) using magnesium acetate as a precursor. Under the chemical equilibrium of etching and re-growth with the assistance of OA, the MgO products were surface functionalized. It was found that such surface functionalized MgO NCs exhibited intense visible light PL with high PL thermal-stability, and the apparent quantum yield was as high as 19 +/- 1%. In addition, through controlling the synthetic temperature and the reaction time, the functionalized surfaces of MgO NCs were facilely tuned, resulting in the tuneable wavelength of the PL from blue-violet to yellow. Different low-coordinated oxygen sites, capping OA and carbonate species on the surface of the MgO nanocrystals were thought to be the origin of PL at different wavelengths. Considering the intense PL, high PL stability at ambient conditions, low cost and low toxicity, such MgO NCs might have potential applications in medicine and biology as a new kind of fluorescent label.National Natural Science Foundation of China[20725310, 20721001, 21073145, 20801045]; National Basic Research Program of China[2007CB815303, 2011CBA00508