金纳米粒子的电化学合成及光谱表征

采用电化学方法合成各种形状的金纳米粒子,生成的金纳米粒子形貌与施加电流有关,通过匀速递增电流电解的方法,可制备得到哑铃形,球形以及棒状金纳米粒子,采用恒电流电解方法主要获得球形及哑铃形纳米粒子。利用透射电镜、紫外-可见光谱及拉曼光谱对金纳米粒子进行相关表征。紫外-可见光谱研究发现金纳米棒出现位于近红外区间的吸收峰(985 nm),由此推测棒的长径比约为6。以结晶紫为探针分子,研究了金纳米粒子的表面增强拉曼光谱(SERS)效应,并分析得出其平躺的吸附模式。根据形貌表征的结果推断了纳米粒子的生长机理。     

Sonochemical preparation of SnS and SnS2 nano- and micropowders and their characterization

Sonochemical production of tin(II) and tin(IV) sulfides is investigated. Different conditions of syntheses are examined: used solvent (ethanol or ethylenediamine), source of tin (SnCl₂ or SnCl₄), the molar ratio of thioacetamide to the tin source, and time of sonication. The obtained powders are characterized by the X-ray diffraction method (PXRD), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDX), and the Tauc method. Raman and FT-IR measurements were performed for the obtained samples, which additionally confirmed the crystallinity and phase composition of the samples. The influence of experimental conditions on composition (is it SnS or SnS₂), morphology, and on the bandgap of obtained products is elucidated. It was found that longer sonication times favor more crystalline product. Each of bandgaps is direct and most of them show typical values – c.a. 1.3 eV for SnS and 2.4 eV for SnS₂. However, there are some exceptions. Synthesized powders show a variety of forms such as needles, flower-like, rods, random agglomerates (SnS₂) and balls (SnS). Using ethanol as a solvent led to powders of SnS₂ independently of which tin chloride is used. Sonochemistry in ethylenediamine is more diverse: this solvent protects Sn²⁺ cations from oxidation so mostly SnS is obtained, while SnCl₄ does not produce powder of SnS₂ but Sn(SO₄)₂ instead or, at a higher ratio of thioacetamide to SnCl₄, green clear mixture.     

金银合金纳米粒子的合成及其SERS研究

采用柠檬酸三钠作为保护剂,通过水合肼还原的方法合成了不同组成的Au-Ag合金纳米粒子。UV-Vis光谱中只观察到一个位于单金属银和金之间的等离子体共振峰, 表明金银已形成合金。TEM显示合成的粒子非核壳结构,金银分布均匀, 合金粒径在25 nm左右。用吡啶为探针分子研究了合金的表面增强拉曼光谱(SERS), 结果表明吡啶在合金表面表现出了不同于纯金和纯银的行为。     

Synthesis and Characterization of CdS Nanoparticles with Strong Electrolyte Behavior

The CdS nanoparticles whose structure is similar to a strong electrolyte were synthesized by the colloidal chemical method. The CdS nanoparticles with Cd²⁺-rich surface are capped by the electrically neutral ligand of 2,2-bipyridine (bpy), and the counterion, BPh₄ ^-, is adsorbed around the particle as balance charge. The donation from 2,2-bipyridine at 2-position to the Cd²⁺-rich surface of the CdS nanoparticles was characterized by X-ray photoelectron spectroscopy (XPS). These CdS nanoparticles can redisperse in pyridine (py) or DMF, and have high stability. The determination of electroconductivity and the electrophoresis deposition in dilute solution containing the CdS nanoparticles further prove the rationality of the above electrolyte structure of the CdS nanoparticles.     

Interface modification of MoS2 counter electrode/electrolyte in dye-sensitized solar cells by incorporating TiO2 nanoparticles

To achieve the high efficiency in dye-sensitized solar cells (DSSCs), the interface modification of MoS₂ counter electrode (CE)/electrolyte should be carried out. Making the modified MoS₂ CE by incorporating TiO₂ nanoparticles provides possibilities to enhance electrocatalytic activity. The DSSCs with the MoS₂/TiO₂ CE show enhanced performance compared with DSSCs with the MoS₂ CE. The experimental results revealed that the MoS₂/TiO₂ nanocomposite influences on the power conversion efficiency by enhancing electrocatalytic activity and increasing the active surface area that serve to increase the short circuit current. This understanding can provide guidance for the development of highly efficient DSSCs with platinum-free CEs.     

憎水性金属纳米粒子及其LB膜的制备与光谱表征

用油酸钠和十四烷基硫醇作为稳定剂,制备了高度单分散的疏水性银和金纳米溶胶。考察了单粒子层的π－Ａ曲线并建造了纳米粒子的ＬＢ膜。通过紫外可见光谱讨论了纳米粒子的分散状态,由红外光谱结果讨论了纳米粒子表面有机吸附层的状态。     

无机类富勒烯MoS2纳米材料的制备与表征

采用简单的沉淀法 ,利用聚乙二醇作为分散剂 ,盐酸羟铵为还原剂 ,以硫化铵为硫源合成了具有无机类富勒烯结构的纳米二硫化钼 ,通过粉末X射线衍射 (XRD)、扫描电镜 (SEM )和高分辨透射电镜 (HRTEM)等方法对其形貌和结构进行了表征 .结果表明 ,用聚乙二醇做分散剂 ,使其吸附在前驱物表面使颗粒环境呈现出一个相对隔绝的状态 ,在煅烧过程中 ,其空间位阻作用有利于MoS2 纳米颗粒形成无机类富勒烯结构 .     

Application of sonochemically synthesized SnS and SnS2 in the electro-Fenton process: Kinetics and enhanced decolorization

SnS and SnS₂ powders were synthesized with the use of ultrasound. The indirect sonication was applied with ultrasound frequency 40 kHz and acoustic power 38 W/L. Products of syntheses were examined with PXRD, TEM, EDX, XPS, and UV–Vis (the Tauc method) investigations. The resulting microparticles were used for tip coating of copper cathodes. These electrodes were used in the degradation of model azo-dye Metanil Yellow by the electro-Fenton process. The efficiencies of degradation using copper, SnS-coated copper, and SnS₂-coated copper cathodes are compared. Kinetics of degradation of Metanil Yellow in the electro-Fenton process with the application of three different cathodes is also investigated. It was found that the degradation follows pseudo-first-order and that SnS-coated copper cathode improves the efficiency of degradation, while SnS₂-coated copper cathode decreases the efficiency of degradation.     

桑色素修饰金纳米粒子自组装膜的制备及其性能研究

采用水相硅烷化方法,将γ-氨基丙基三乙氧基硅烷[H₂N(CH₂)₃Si(OC₂H₅)₃](APES)组装在石英表面,在基底表面修饰上氨基为末端的单层膜,并进一步在这种功能化的单层膜基底上组装金纳米粒子得到金纳米粒子/APES/石英的纳米复合结构。以制备的金纳米粒子自组装膜修饰石英为基底及DL-半胱胺酸为中介,利用桑色素(Morin)和DL-半胱胺酸的化学吸附作用,将桑色素间接组装在金纳米粒子自组装膜修饰石英基底表面,所构建的桑色素修饰金纳米粒子自组装膜对三苯基锡有灵敏的荧光识别作用。文章着重研究了桑色素修饰金纳米粒子自组装膜的制备以及组装条件对其荧光行为的影响,探讨了膜的响应特性及响应机理。     

掺杂铁的CeO2纳米颗粒的制备与表征

利用反相共沉淀法,合成了掺杂过渡金属铁的CeO2纳米颗粒.通过X射线衍射(XRD)、透射电镜(TEM)、傅里叶变换红外(FTIR)光谱、紫外-可见(UV-Vis)光谱等测试手段对产物进行了分析和表征.结果表明,掺杂铁的CeO2纳米颗粒是纯立方莹石结构;过渡金属铁掺入了CeO2的晶格;其相比于不掺铁的CeO2纳米颗粒吸收...     

Doping of Fullerene‐Like MoS2 Nanoparticles with Minute Amounts of Niobium

Inorganic fullerene‐like closed‐cage nanoparticles of MoS₂ and WS₂ (IF‐MoS₂; IF‐WS₂), are synthesized in substantial amounts and their properties are widely studied. Their superior tribological properties led to large scale commercial applications as solid lubricants in numerous products and technologies. Doping of these nanoparticles can be used to tune their physical properties. In the current work, niobium (Nb) doping of the nanoparticles is accomplished to an unprecedented low level (≤0.1 at%), which allows controlling the work function and the band gap. The Nb contributes a positive charge, which partially compensates the negative surface charge induced by the intrinsic defects (sulfur vacancies). The energy diagram and position of the Fermi level on the nanoparticles surface is determined by Kelvin probe microscopy and optical measurements. Some potential applications of these nanoparticles are briefly discussed.     

聚电解质包覆的铕(Ⅲ)配合物@SiO2荧光纳米粒的合成与性质

以二苯甲酰甲烷(DBM)、邻菲罗琳(phen)和丙烯酸(AA)为配体,制备了铕的配合物Eu(Ⅲ)(DBM)2-(phen)(AA).利用St(o)ber法合成了SiO2纳米粒.通过超声辅助,将脂溶性的强荧光铕配合物吸附到SiO2纳米粒上,再包覆阳离子聚电解质聚二烯丙基二甲基氯化铵(PDAC)和阴离子聚电解质聚丙烯酸(P...     

Preparation and Characterization of CdHgTe Nanoparticles and Their Application on the Determination of Proteins

CdHgTe nanoparticles (NPs) with the emission in the near-infrared regions were prepared in aqueous solution, and were characterized by transmission electron microscopy, X-ray diffraction spectrometry, spectrofluorometry and ultraviolet-visible spectrometry. Based on the fluorescence quenching of CdHgTe NPs in the presence of proteins, a novel method for the determination of proteins with CdHgTe NPs as a near-infrared fluorescence probe was developed. Maximum fluorescence quenching was observed with the excitation and emission wavelengths of 500 and 693 nm, respectively. Under the optimal conditions, the calibration graphs were linear in the range of 0.04 × 10⁻⁶–5.6 × 10⁻⁶ g ml⁻¹ for lysozyme (Lyz) and 0.06 × 10⁻⁶–6.1 × 10⁻⁶ g ml⁻¹ for bovine hemoglobin (BHb), respectively. The limits of detection were 13 ng ml⁻¹ for Lyz and 27 ng ml⁻¹ for BHb, respectively. Four synthetic samples were determined and the results were satisfied.     

琼脂糖凝胶/纳米金复合结构的制备及其表面增强拉曼性质

以琼脂糖凝胶为模板,将预先制备好的胶体金颗粒负载在琼脂糖凝胶的网状结构中,制备了琼脂糖凝胶/纳米金复合膜结构,采用透射电子显微镜、扫描电子显微镜、紫外-可见-近红外光谱仪对复合膜的结构和光学性质进行了表征,实验数据表明纳米金颗粒均匀的分散在琼脂糖凝胶膜上,并且呈现出优异的光学吸收特性。基于琼脂糖凝胶的溶胀收缩特性和纳米金颗粒可调的表面等离子体共振吸收特性,将琼脂糖凝胶/纳米金复合膜作为表面增强拉曼(SERS)基底材料,研究了其对拉曼信号分子尼罗蓝A(NBA)的SERS检测效果。结果表明,琼脂糖凝胶的多孔网状结构为纳米金颗粒的富集提供了良好的载体,随着琼脂糖凝胶在空气中失水收缩,纳米金颗粒间距离逐渐缩短,产生动态的热点效应,对拉曼信号分子具有良好的增强效应。     

牛血红蛋白与纳米雄黄相互作用的光谱研究

采用紫外-可见吸收光谱、荧光光谱研究牛血红蛋白(bovine hemoglobin,简称BHb)与纳米雄黄的相互作用。从紫外-可见吸收光谱可观察到,随着纳米雄黄浓度的增加,牛血红蛋白406 nm附近的特征Soret吸收带红移至413 nm,且强度逐渐降低。强度的降低表明纳米雄黄可能使部分血红素辅基逐渐从它们的键腔中脱离出来。特征峰位的红移推测为纳米雄黄中的砷结合了血红蛋白中的氧,诱导血红蛋白脱氧,变成脱氧血红蛋白,其构象由R态转变成T态。由荧光光谱研究可以得出随着纳米雄黄浓度的增加,牛血红蛋白338 nm处的荧光强度逐渐减弱,Stern-Volmer方程分析表明,纳米雄黄静态猝灭牛血红蛋白的内源荧光。紫外-可见吸收光谱与荧光光谱的计算结果均表明,牛血红蛋白与纳米雄黄的结合常数k的数量级达到109。     

CaAl2O4:Eu2+,Nd3+纳米粉体的合成与发光性质

采用溶胶-凝胶法制备了CaAlO4：Eu^2＋,Nd^3＋纳米粉体发光材料。利用DTA,TG,XRD,SEM,光谱分析等手段对样品进行了结构和性能分析。实验结果表明,800℃烧结的样品形成已CaAl2O4晶相,样品平均晶粒尺寸为20～40nm,与CaAlO4：Eu^2＋,Nd^3＋粗晶材料相比,样品的发光光谱发生了“蓝移”,热释光峰值向高温移动了96℃,且曲线形状变宽,发光衰减是由初始的快衰减和随后的慢衰减构成,发光余辉时间5h。     

室温合成硫化银纳米粒子及其X射线光电子能谱表征

在常温常压下制备了硫化银纳米粒子,选用廉价的氧化银和硫粉为原料,采用多聚甲醛为还原剂,并在乙二胺体系中完成了反应。所得产物用X射线光电子能谱、X射线粉末衍射和透射电镜进行了表征。X射线粉末衍射表明：产物为单斜相的硫化银;透射电子显微镜表明：产物为直径约为100nm的棒状纳米粒子,其对应的电子衍射斑点可以指标成(120)和(303),说明产物的结晶较好;X射线光电子能谱分析表明：产物中Ag属 1价而S属-2价,它们的原子个数比为Ag：S=1：0．453。对比实验表明：多聚甲醛和无水乙二胺都起了很关键的作用;多聚甲醛起了多重作用,它既是溶剂,又是中和剂,用以除去反应的副产物多个点-甲酸,从而加速了反应的进行。     

两种以Znq2为基体的新型电致发光材料的合成与性能

以8-羟基喹啉为配体的金属配合物是一种性能优良的有机电致发光材料,其中有关8-羟基喹啉铝(Alq₃)研究已有大量报道,8-羟基喹啉锌(Znq₂)研究还有待发展。介绍了两种以Znq₂为基体的新型有机电致发光材料Znq₂(H₂O)₂和(Znq₂)₄的合成方法。用IR、XRD、TG、DTA和荧光测试方法进行表征与分析表明:Znq₂(H₂O)₂和(Znq₂)₄的玻璃化温度(T_g)分别为104.2℃和204.9℃;在161℃下Znq₂(H₂O)₂脱去水分子成为Znq₂,在361℃高温下四聚体(Znq₂)₄裂解为单体Znq₂;Znq₂(H₂O)₂和(Znq₂)₄具有很好的发光性能,在光致发光谱中λ_max分别是505,550nm。     

自组装银纳米粒子及其SERS增强效应

采用柠檬酸三钠还原硝酸银方法制备出银纳米粒子, 并通过在玻璃表面修饰3-氨基丙基-三乙氧基硅烷( APTES)对银纳米粒子进行自组装。利用紫外-可见(UV-Vis)吸收光谱和扫描电子显微镜(SEM)测试手段对样品进行分析和表征。由测试结果可知银纳米粒子的尺寸比较均匀, 组装致密度较高, 基本以亚单层的形式分布于基底表面。进一步研究了以结晶紫(CV)为探针分子的自组装基底的表面增强拉曼光谱(SERS), 计算发现该基底的拉曼增强因子数量级达106。结果表明: 银纳米粒子自组装基底具有良好的SERS增强效应, 为痕量CV的检测提供了有效的方法。