掺铟氧化锌纳米盘的制备、结构及性质研究

热蒸发Zn、In₂O₃和C粉混合物, 在没有催化剂的条件下制备出掺铟氧化锌纳米盘. 纳米盘呈六边形或十二边形, 均是结晶完好的纤锌矿结构的单晶, 对角线长度约1~3 μm , 厚度40~100 nm. 纳米盘的生长是由自催化固-液-气(V-L-S)机理控制, 在实验条件下Zn和In的液滴抑制纳米盘 [0001]方向的生长. EDS分析表明, 六边形纳米盘和十二边形纳米盘中In的含量相近, 约为2.2%. 室温光致发光谱显示掺杂后的紫外发射峰位稍有蓝移, 同时半高宽(HWHM)变大, 没有观察到绿光发射峰位.     

柠檬酸盐稳定的水溶性CdSe量子点的合成及表征

以柠檬酸三钠为稳定剂在水溶液中合成了水溶性CdSe量子点,用X射线粉末衍射、透射电镜、紫外-可见吸收光谱和荧光发射光谱对CdSe量子点的结构、形貌及其荧光性质进行了表征.结果表明合成的CdSe量子点为立方闪锌矿结构,呈球形,分散性良好,平均尺寸约为2.6nm,具有窄且对称的荧光发射光谱,半峰宽为45nm.     

水溶性的CdSe/ZnS纳米微粒的合成及表征

用L-半胱氨酸(Cys)作为稳定剂，合成了水溶性的CdSe/ZnS核壳结构的半导体纳米微粒。吸收光谱和荧光光谱表明，CdSe/ZnS纳米微粒比单一的CdSe纳米粒子具有更优异的发光特性。透射电子显微镜（TEM）、ED和XPS表征了CdSe/ZnS纳米微粒的结构、分散性及形貌。红外光谱证实半胱氨酸分子中的硫原子和氧原子参加了与纳米粒子表面的金属离子的配位作用。     

水溶性的CdSe/CdS/ZnS量子点的合成及表征

用L-半胱氨酸盐(Cys)作为稳定剂,合成了水溶性的双壳结构的CdSe/CdS/ZnS半导体量子点。吸收光谱和荧光光谱结果表明,双壳结构的CdSe/CdS/ZnS纳米微粒比单一的CdSe核纳米粒子和单核壳结构的CdSe/CdS纳米粒子具有更优异的发光特性。用透射电子显微镜(TEM)、ED、XRD、XPS和FTIR等方法对CdSe核和双壳层的CdSe/CdS/ZnS纳米微粒的结构、分散性及形貌分别进行了表征。     

A novel ultrasound-assisted approach to the synthesis of CdSe and CdS nanoparticles

Hexagonal CdSe and hexagonal CdS nanoparticles have been prepared using Cd(Ac)₂ and less hazardous elemental Se or S as precursors, respectively, with the aid of ultrasound irradiation under an atmosphere of H₂/Ar (5/95, V/V). The products consist of 7-10 nm nanocrystallites which aggregated in the form of polydispersive nanoclusters with sizes in the range 30-40 nm in the case of CdSe, and near monodispersive nanoclusters with a mean size of about 40 nm in the case of CdS. X-ray diffraction, high-resolution TEM and SAED patterns (selected area electron diffraction patterns) show that the as-prepared particles are well crystallized. X-ray photoelectron spectroscopy (XPS) measurements further confirm the formation of CdSe and CdS. Diffuse reflection spectra indicate that both the CdSe and the CdS nanocryslallites are direct band-gap semiconductors with band-gap values of about 1.83 and 2.62 eV, respectively. Control experiments demonstrate that the hydrogen is the reducing agent, and the extreme high temperature induced by the collapse of the bubble accelerates the reduction of elemental Se or S by hydrogen. An ultrasound assisted in situ reduction/combination mechanism is proposed.     

Ultrasonic synthesis of In-doped SnS nanoparticles and their physical properties

Indium (In)-doped Tin (II) Sulfide (SnS) nanoparticles (NPs) were synthesized by an ultra-sonication method and their optical, electrical, dielectric and photocatalytic properties were investigated. XRD patterns of the obtained NPs indicated formation of orthorhombic polycrystalline SnS. Field emission scanning electron microscopy exhibited flower-like NPs with particle sizes below 100 nm for both SnS and In-doped SnS samples. Optical analysis showed a decrease in energy band gap of SnS NPs upon In doping. In addition, electrical results demonstrated p-type nature of the synthesized SnS NPs and enhanced electrical conductivity of the NPs due to increased tin vacancy. Dielectric experiments on SnS NPs suggested an electronic polarizations effect to be responsible for changing dielectric properties of the particles, in terms of frequency. Finally, photocatalytic experiments revealed that high degradation power can be obtained using In-doped SnS NPs.     

光谱法研究CdSe/CdS/ZnS量子点与壳聚糖的复合

通过CdSe/CdS/ZnS量子点与壳聚糖之间的静电作用,用共混法制备了壳聚糖-CdSe/CdS/ZnS复合物.用荧光光谱、紫外-可见光谱、红外光谱对所得的壳聚糖-CdSe/CdS/ZnS复合物进行了表征.研究结果表明:壳聚糖-CdSe/CdS/ZnS复合物具有良好的光学性能.     

Preparation and characterization of high-specific-surface-area activated carbons from K2CO3-treated waste polyurethane

An activated carbon with high specific surface area was prepared from polyurethane foam by chemical activation with K2CO3 and the influences of carbonization temperature and impregnation ratio on the pore structure of the prepared activated carbon were investigated. It was found that the specific surface area of the activated carbon was at a maximum value (about 2800 m(2)/g) at a carbonization temperature of 1073 K and at an impregnation ratio of 1.0. It was concluded that the polyurethane foam structure was modified during impregnation by K2CO3, K2CO3 promoted charring during carbonization, and then the weight loss behavior was changed below 700 and above 1000 K, carbon in the char was consumed by K2CO3 reduction, and this led to the high specific surface area. The prepared activated carbon had a very sharp micropore size distribution, compared with the commercial activated carbon having high specific surface area. The amounts of three organic vapors (benzene, acetone, and octane) adsorbed on the prepared activated carbons was much larger than those on the traditional coconut shell AC and the same as those on the commercial activated carbon except for octane. We surmised that the high specific surface area was due to the modification of the carbonization behavior of polyurethane foam by K2CO3.     

CdSe纳米结构单元的制备与自组装

纳米CdSe作为一种重要的半导体纳米材料,在发光二极管、生物标记、太阳能电池等领域有着广泛的应用。本文综述了CdSe纳米结构单元制备与自组装的最新研究进展。归纳出了6种有代表性的制备与组装方法,详细介绍了这些方法的原理以及采用这些方法制备的CdSe纳米结构。最后,对这一领域的发展方向作了展望。     

Preparation of CdSe/ZnSe Core-shell Nanocrystal in One-step Reaction

IntroductionSemiconductor nanocrystals show strong size-de-pendent properties when their size is similar to or smal-ler than the excition Bohr radius of the bulk materialsand quantum confinement occurs for the space-con-fined motion of the electrons and holes in the nano-re-gion of materials[1—5].Because of the excellent opticaland electronic properties,semiconductor nanocrystalsare currently being investigated as emitting materials forthin-film light-emitting devices(LED)[6,7],low-thresh-ol…     

纳米CdSe与聚4-乙烯基吡啶盐的复合与表征

用巯基乙酸作稳定剂在水相中合成了CdSe纳米颗粒. 聚4-乙烯基吡啶季铵盐(PVPNI)通过静电作用与CdSe纳米颗粒复合形成了纳米复合材料.该复合材料通过红外光谱数据（IR）、电感耦合等离子发射光谱（ICP-AES）、透射电镜（TEM）等方法进行了表征,并通过紫外可见吸收光谱(UV-Vis)和荧光光谱(PL)对其光学性质进行了研究.结果表明,复合材料的形成,改善了纳米CdSe的分散性,并提高了纳米CdSe的荧光强度.     

Synthesis and characterization of gallium oxide nanoparticles

This review is based on the literature describing several methods for the synthesis of gallium oxide nanoparticles. Several techniques have been used for the synthesis of gallium oxide Ga₂O₃ nanoparticles. Gallium oxide Ga₂O₃ nanoparticles have been synthesized from different precursors. Different synthetic methods and different precursors produce nanoparticles which vary in size and shape. Over a dozen of synthetic methods for preparation of gallium oxide Ga₂O₃ nanoparticles together with the characterization techniques used have been discussed.     

无膦方法合成高质量CdSe纳米晶及其光学性质

以合成的十碳酸镉作为Cd前驱体, 十八烯作为单质硒溶剂, 并添加十八胺作为活性剂, 在无三丁基膦或三辛基膦参与的条件下, 以较低温度制备了具有闪锌矿结构的高质量的CdSe纳米晶. 利用吸收光谱、荧光光谱(PL)、X射线衍射(XRD)、透射电镜(TEM)对不同反应时间得到的CdSe纳米晶进行形貌和光谱性质表征. 实验结果表明, 采用该无膦法只需调控反应时间就可得到粒径均一、分散性好的CdSe纳米晶, 其荧光波长可覆盖470-630 nm的可见光区, 而荧光峰半高宽则始终保持在24-30 nm之间并具有较高的荧光量子产率(535 nm处大于60%). 最后, 对CdSe纳米晶量子产率随反应时间变化的原因进行了分析.     

不同形貌/晶型CdSe纳米材料的合成

以乙二胺(en)为溶剂, 通过调控反应物中镉源与硒源的摩尔比得到了不同形貌与晶型的CdSe纳米材料, 达到了同时调控形貌与晶型的目的. 当反应物中镉源与硒源摩尔比为1∶1时, 得到的产物为en体系常见的六方相棒状CdSe纳米晶体；当反应物中镉源与硒源摩尔比为1∶2时, 得到的产物为立方相CdSe纳米颗粒. 进一步研究结果表明, 反应体系中Se^2－离子生成的多少及速度是影响反应进程得到不同产物的关键.     

模板法制备CdSe纳米材料及其光电性能

采用电化学沉积法,在阳极氧化铝（AAO）模板中成功制备出CdSe纳米管和纳米线。利用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X射线衍射分析（XRD）和能量色散X射线光谱仪（EDS）对材料的形貌、结构和元素组成进行了表征。借助紫外-可见吸收光谱等对材料光催化活性进行了研究。结果表明：通过控制沉积电量可成功制备CdSe纳米管和纳米线;CdSe纳米材料为立方晶型与六方晶型的混合,经350℃退火处理后,CdSe纳米材料中由立方晶型向六方晶型转变,光照开路电位差值明显增强,在0 V（vs SCE）电位下的光照电流密度也有所提高,光电转换性能增强;CdSe纳米线的吸收边在710 nm左右,禁带宽度约为1.85 eV,CdSe纳米管相对于CdSe纳米线具有更高的光电转换性能和光催化活性,经7 h光照后,罗丹明B降解效率高达53.93%,另外,本文还讨论了CdSe纳米材料在AAO模板孔壁的生长机理。     

模板法制备CdSe纳米材料及其光电性能

采用电化学沉积法,在阳极氧化铝（AAO）模板中成功制备出CdSe纳米管和纳米线。利用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X射线衍射分析（XRD）和能量色散X射线光谱仪（EDS）对材料的形貌、结构和元素组成进行了表征。借助紫外-可见吸收光谱等对材料光催化活性进行了研究。结果表明：通过控制沉积电量可成功制备CdSe纳米管和纳米线;CdSe纳米材料为立方晶型与六方晶型的混合,经350℃退火处理后,CdSe纳米材料中由立方晶型向六方晶型转变,光照开路电位差值明显增强,在0 V（vs SCE）电位下的光照电流密度也有所提高,光电转换性能增强;CdSe纳米线的吸收边在710 nm左右,禁带宽度约为1.85 eV,CdSe纳米管相对于CdSe纳米线具有更高的光电转换性能和光催化活性,经7 h光照后,罗丹明B降解效率高达53.93%。另外,本文还讨论了CdSe纳米材料在AAO模板孔壁的生长机理。     

Synthesis and characterization of water-soluble CdSe nanoparticles capped by AOT

Water-soluble CdSe nanoparticles were synthesized using AOT (sodium bis(2-ethylehexyl)-sulfosuccinate) as stabilizer, cadmium acetate and Na2SeSO3 as precursors in aqueous phase. The influence of some key factors, such as reaction time, temperature, concentration and molar ratio of precursors on the optical properties of CdSe nanoparticles was systematically investigated through UV-Vis and PL spectra. Powder X-ray diffraction (XRD) was used to characterize the crystalline structure of synthesized CdSe nanoparticles. As-prepared CdSe nanoparticles exhibit an apparent quantum confinement effect and typical hexagonal wurtzite structures. Finally, the optimal experimental conditions were obtained.     

基于CdSe/ZnS量子点构建多巴胺荧光检测方法的研究

以CdSe/ZnS量子点为荧光探针,基于多巴胺对CdSe/ZnS量子点的荧光猝灭效应,建立了一种可快速测定多巴胺的荧光检测方法。在最优实验条件下(pH7.4,反应时间20min),多巴胺浓度在0.01~0.7μmol/L范围内与CdSe/ZnS量子点的荧光猝灭强度比值呈良好的线性关系(r=0.996),方法检出限为1.6×10-4μmol/L,相对标准偏差为1.2%。与文献报道的方法相比,该方法的检出限更低,更为灵敏,可用于多巴胺注射液及人体尿样中多巴胺的快速检测。     

11-巯基烷酸修饰cdse/cds纳米晶的合成及荧光增敏法测定溶菌酶

巯基烷酸;纳米晶;量子点;cdse/cds;溶菌酶     

Semiconductor quantum dots and metal nanoparticles: syntheses,optical properties,and biological applications

We review the syntheses, optical properties, and biological applications of cadmium selenide (CdSe) and cadmium selenide–zinc sulfide (CdSe–ZnS) quantum dots (QDs) and gold (Au) and silver (Ag) nanoparticles (NPs). Specifically, we selected the syntheses of QDs and Au and Ag NPs in aqueous and organic phases, size- and shape-dependent photoluminescence (PL) of QDs and plasmon of metal NPs, and their bioimaging applications. The PL properties of QDs are discussed with reference to their band gap structure and various electronic transitions, relations of PL and photoactivated PL with surface defects, and blinking of single QDs. Optical properties of Ag and Au NPs are discussed with reference to their size- and shape-dependent surface plasmon bands, electron dynamics and relaxation, and surface-enhanced Raman scattering (SERS). The bioimaging applications are discussed with reference to in vitro and in vivo imaging of live cells, and in vivo imaging of cancers, tumor vasculature, and lymph nodes. Other aspects of the review are in vivo deep tissue imaging, multiphoton excitation, NIR fluorescence and SERS imaging, and toxic effects of NPs and their clearance from the body. Figure Semiconductor quantum dots and metal nanoparticles have extensive applications, e.g., in vitro and in vivo bioimaging Tamitake Itoh and Abdulaziz Anas contributed equally to this article.