Pt/Au双金属纳米粒子和壳聚糖/二氧化硅溶胶-凝胶杂化膜漆酶传感电极的邻苯二酚检测

利用Pt/Au双金属纳米粒子和壳聚糖/二氧化硅（CS-SiO₂）溶胶-凝胶复合材料固定漆酶（Lac）,制得漆酶生物电极（Pt-Au-CS-SiO₂-Lac/GC）. 采用循环伏安曲线（CV）研究了邻苯二酚（CC）在该漆酶电极的电化学性能. 实验结果表明,Pt-Au-CS-SiO₂-Lac/GC电极对邻苯二酚的电催化在8×10^-7 ~ 1×10^-4 mol·L^-1浓度范围,其浓度与还原峰电流呈线性关系,相关系数r = 0.9993,检出限7.9×10^-8 mol·L^-1,该检测方法灵敏度高,线性范围宽,稳定性好.     

Pt/MnO2纳米结构催化剂的制备与结构表征

采用一种简单的方法合成了Pt/MnO2纳米结构催化剂.通过改变还原时间、反应温度、聚乙烯吡咯烷酮（PVP）的用量、Pt负载量等,研究了反应条件对Pt/MnO2纳米结构催化剂的Pt纳米粒子的粒径大小、粒径分布和分散性影响.并在最佳条件下合成一系列不同载体和Pt负载量的Pt/MnO2纳米结构催化剂.通过X射线衍射（XRD）...     

Pt/Ni双金属纳米溶胶的制备及催化制氢性能

采用化学共还原法制备了聚乙烯吡咯烷酮(PVP)稳定的Pt/Ni双金属纳米溶胶.采用紫外-可见光谱(UV-Vis)、透射电子显微镜(TEM)对所合成的Pt/Ni双金属纳米溶胶进行了表征, 并系统研究了PVP用量、还原剂用量和浓度、双金属比例对该双金属纳米溶胶催化剂催化性能的影响.结果表明, 所制备的双金属纳米溶胶的平均粒径在2.0 nm左右, Pt/Ni双金属纳米溶胶的催化活性比Pt及Ni单金属纳米溶胶的高, 当Pt/Ni摩尔比为1:4时, 纳米溶胶的催化活性最高, 其活性值为16640 mol_H2·mol_Pt^-1·h^-1.所制备的Pt/Ni双金属纳米溶胶催化剂具有很好的耐久性, 5次催化实验后该催化剂仍保持较高的催化活性.该双金属纳米溶胶催化NaBH₄水解反应的活化能为48 kJ/mol.     

Pt/Au双金属纳米微粒的催化性能

制备了不同比例的Pt/Au双金属纳米微粒,应用UV-VIS、TEM等手段对其结构进行了表征,并比较了它们对丁醛氢化还原反应的催化活性.     

SnO2纳米粒子的制备与表征

The SnO2 nano-particles with rutile structure were prepared by a Water/Oil (W/O) microemulsion system, composed of Triton X-100 1-hexanol/Cyclohexane/Water. The particles were also compared with that synthesized by citric acid method. The powders were characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM) and infrared spectroscopy (IR). The result showed that the SnO2 particles prepared by microemulsion had fine shape and narrow range of particle size distribution. The crystallite size calcined at 600℃ was 11.49 nm,while the crystallite size prepared by citric acid method was about 17.4 nm.     

Pt/Cu双金属纳米颗粒的制备及其催化制氢活性

采用化学共还原法合成了聚乙烯吡咯烷酮保护的Pt/Cu双金属纳米颗粒(BNPs),并采用紫外可见吸收光谱、透射电子显微镜、高分辨透射电子显微镜等对所合成的Pt/Cu BNPs进行了表征。研究了化学组成对Pt/Cu BNPs催化Na BH4水解制氢性能的影响。结果表明,所制备的Pt/Cu BNPs平均粒径为1.8~2.3nm,其催化活性远高于单金属Pt和Cu NPs的活性,其中Pt90Cu10BNP的催化活性最高,其在30℃的条件下,催化Na BH4制氢的活性可达6570mol-H2·mol-cat-1·h-1,约为相同粒径的Pt单金属NP的1.6倍。密度泛函理论的计算结果表明,Pt/Cu BNPs优异的催化性能可归因于电荷转移效应,Pt原子与Cu原子之间发生的电子转移使得Pt原子带负电而Cu原子带正电,荷电的Pt和Cu原子成为催化反应的活性中心。     

Au/Ag核-壳结构纳米粒子的制备及其SERS效应

随着大量有关表面增强拉曼散射 (SERS)的实验和理论研究的开展 ,金属纳米粒子作为一类重要的 SERS增强介质 ,已引起了人们浓厚的研究兴趣 [1] .而 Au和 Ag作为最常用的活性基底物质 ,更是研究的热点 [2 ,3 ] .最近 ,美国印第安那大学的 Nie等 [4 ] 在单个银纳米粒子上 ,观察到高达 1 0 14 ～ 1 0 15的SERS因子 .同时 ,他们的另外一项工作表明银纳米粒子的形状和大小对 SERS活性有很大影响 [5] .但是 ,由于 Ag溶胶制备的重复性较差 ,且粒度分布不均匀 ,通过控制银颗粒大小而调控 SERS活性是相当困难的[6] .与 Ag相比 ,Au在可见光…     

基于Pt/Au双金属修饰针灸针的非酶葡萄糖传感器

通过在不锈钢针灸针（AN）表面依次电沉积金（Au）纳米颗粒和铂（Pt）纳米颗粒,基于它们在AN表面的协同作用,实现了一种用于非酶葡萄糖检测的电化学生物传感器。首先,通过扫描电子显微镜对其功能界面（Pt/Au/AN）进行表征,结果显示类似卷心菜的纳米材料均匀致密地分布在AN表面。然后,通过循环伏安法和电化学阻抗法对Pt/Au/AN电极的电化学特性进行了研究。结果表明,与Au/AN或Pt/AN电极相比,Pt/Au/AN电极对葡萄糖氧化表现出优越的电催化活性。这表明双金属Pt/Au的接触界面是葡萄糖氧化的重要电催化位点。在pH7.4的模拟生理介质中,制得传感器的线性范围为0.1~35 mmol·L^-1,检测限为0.0763 mmol·L^-1,对葡萄糖的检测表现出较高的灵敏度和良好的抗干扰性能、稳定性。此外,该传感器已成功用于人体血清葡萄糖的检测。     

SiO2 /Au核壳结构纳米粒子的制备及表征

通过以金纳米粒子为表面晶种和壳生长的方法制备了金纳米壳包覆二氧化硅的复合纳米粒子。采用TEM 和UV-Vis对复合粒子进行了表征和研究，结果表明所得到的复合粒子粒径均匀、金纳米壳光滑完整，且壳厚度可通过反应物的用量来控制。当核半径与壳厚度之比在4到13之间变化时,复合粒子的光学共振峰在可见光区到近红外光区范围内可发生大于500 nm波长的移动。     

单分子层保护纳米 Au 粒子表面配位催化剂的制备及其应用

 贵金属纳米粒子由于其小尺寸效应而表现出特殊的催化性能. 综述了纳米 Au 粒子表面配位催化剂的制备方法及其在催化中的应用. 由于 Au 可与硫化物形成配位键, 所以硫化物可在 Au 表面形成有序单分子膜. 单分子膜保护的 Au 纳米粒子具有非常好的溶解性、分散性、稳定性, 以及由不同的表面功能团而导致的不同的催化性能. 该催化体系兼具均相催化剂和多相催化剂的特点, 这对开发新型催化剂具有重要的理论和实际意义.     

Local structural characterization of Au/Pt bimetallic nanoparticles

In this study, we examined the amount-dependent change in morphology for a series of Au/Pt bimetallic nanoparticles synthesized using chemical reduction. The Au/Pt molar ratio was varied from 1/1 to 1/4 to synthesize Pt shell layers with different thicknesses. We have obtained that these bimetallic nanoparticles can form flower-like nanoparticles. Moreover, an extended X-ray absorption fine structure (EXAFS) analysis was used to demonstrate the structure of Au/Pt bimetallic nanoparticles. The EXAFS results confirmed the formation of a core–shell structure and inter-diffusion between Au and Pt atoms. The composition of the shell layer was found to be Pt-enriched Au/Pt alloy.     

Pt@Ag/Pt复合型纳米颗粒的合成与表征

通过吸附在铂纳米颗粒表面的氢交替还原硝酸银和氯铂酸,得到了复合型纳米颗粒Pt@Ag／Pt,用紫外-可见吸收光谱（UV-Vis）、透射电子显微镜（TEM）、X-射线衍射（XRD）对其进行了表征。通过氢化催化苯甲醛反应,由于Pt与Ag双金属间的协同效应,其催化活性较纯铂好。     

ZnO/Ag复合纳米粒子的制备与表征

以乙酸锌为前驱物,乙醇为溶剂,油酸钠为表面修饰剂,采用溶液化学法,在乙醇体系中制得纳米Zn O。然后缓慢加入一定量的硝酸银乙醇溶液,在乙醇的还原作用下将Ag+还原为Ag纳米粒子,制得Zn O/Ag复合纳米粒子。通过紫外-可见吸收光谱(UV-Vis)、荧光光谱(FL)、透射电子显微镜(TEM)和X射线衍射(XRD)等方法对所制备的氧化锌-银复合纳米粒子样品进行表征。结果表明,所合成的Zn O/Ag复合纳米粒子为球形,尺寸为20-30nm且粒径分布较窄。Ag纳米粒子附着于Zn O纳米粒子表面,并起到良好的表面修饰作用。对制备Zn O/Ag复合纳米粒子的机理进行了初步探究。     

Morphology and optical properties of thin silica films containing bimetallic Ag/Au nanoparticles

We have studied the optical spectra in the UV and visible regions, the morphology by scanning electron microscopy (SEM), and the X-ray photoelectron spectra (XPS) of bimetallic Ag/Au nanoparticles incorporated into transparent silicate films in the sol-gel transition stage. The bimetallic nanoparticles, obtained by a combination of photoreduction and thermal reduction, form structures of the alloy or core-shell type. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 44, No. 6, pp. 348–353, November–December, 2008.     

Rh/Co双金属纳米颗粒的制备及其催化制氢性能

以ISOBAM-104为保护剂,采用共还原法制备了一系列不同组成的Rh/Co双金属纳米颗粒(BNPs)。采用紫外-可见吸收光谱、透射电镜及高分辨透射电镜对纳米颗粒的结构及组成进行了表征。结果表明,所制备的Rh/Co BNPs的粒径小于6.0nm,具有合金结构。催化制氢实验结果表明,Rh_(20)Co_(80)BNPs具有最高的催化制氢活性,其TOF值可高达12880mol-H_2·h~(-1)·mol-Rh~(-1),远高于Rh和Co单金属纳米颗粒的催化活性。     

pH敏感的金纳米颗粒的制备及表征

利用立方硅氧烷(odaaps)作为保护剂合成了金纳米颗粒,利用紫外-可见(UV-vis)吸收光谱、透射电镜(TEM)对纳米颗粒进行了表征。通过改变纳米溶胶的pH值,从而改变立方硅氧烷上羧基的存在形式,控制纳米颗粒表面的电荷,实现金纳米颗粒的可逆聚集与分散;当将其pH值降低至2.5时,颗粒能够完全沉淀,加碱调节其pH与原始值(pH=9)一致时,聚集的颗粒会自动重新分散形成溶胶,其具有与起始一致的高分散性。     

Preparation and characterization of nanostructured thin films of Au and Ag nanoparticles synthesized by ascorbic acid on modified glass surface

Immobilization of Ag and Au nanoparticles (NPs) synthesized by ascorbic acid on chemically modified glass surface has been studied. 3‐[2‐(2‐Aminoethylamino)ethylamino]propyl‐trimethoxysilane (AMPTS), N‐(2‐aminoethyl)‐3‐aminopropyltrimethoxysilan, and 3‐trimethoxysilyl‐1‐propanethiol (MSPT) were used as surface modifying agents. To improve immobilization efficiency, the ammonia solution has been used along with the silane reagents, which assisted to adsorb the metal NPs on glass surface. It was found that AMPTS and MSPT have considerable effect on deposition of Ag and AuNPs on glass substrate. The fabricated thin films were characterized by using UV‐Vis spectroscopy, atomic force microscopy, energy‐dispersive X‐ray spectroscopy and subjected to antimicrobial resistance test. The UV–Vis spectra show a distinctive plasmon resonance absorbance peak for thin films of Au and AgNPs prepared with MSPT and AMPTS, respectively. Atomic force microscopy images indicate that formation of Au and AgNPs with spherical morphology after immobilization on the glass substrate and also the dimensions of NPs on the surface appear larger than those observed in the parent colloidal solution. Energy‐dispersive X‐ray spectroscopy measurements confirmed the presence of silver and gold on the modified glass surface, and elemental composition was measured. The Au and AgNPs thin films show antibacterial activity against gram negative (Escherichia coli) and gram positive (Staphylococcus aureus) bacteria in comparison with a blank sample. Copyright © 2015 John Wiley & Sons, Ltd.     

State of the art in the electrochemical characterization of the surface structure of shape-controlled Pt,Au, and Pd nanoparticles

The application of shape-controlled metal nanoparticles in electrocatalysis has improved significantly the activity, selectivity, and even the stability of many relevant electrocatalytic reactions. It is well accepted that, by controlling the shape of the nanoparticles, it is possible to provide nanoparticles with a preferential surface structure. However, to fully understand the capabilities of these nanomaterials, it is extremely relevant to correlate shape, surface structure, and electrocatalytic reactivity. Particularly, establishing the correlations between surface structure and reactivity is the key point to be studied and understood. Consequently, having tools to characterize the surface structure of these nanoparticles is of critical importance. In this short review, we discuss about the progress in the in situ characterization of the surface structure of shaped Pt, Au, and Pd nanoparticles by electrochemical probes. The results here included clearly demonstrate the potentialities of the electrochemical tools to gain detailed information of the surface structure of these shaped nanomaterials.     

Au/Si 载体负载单层Pt 催化剂的制备及其电催化性能的研究

以Si 纳米粉为载体, 通过化学镀的方法在其表面部分沉积纳米Au 颗粒后, 再通过欠电位的方法在Au 颗粒表面沉积了单层及亚单层的Pt. 通过透射电子显微镜(TEM), 循环伏安(CV)等方法对所制备的Pt/Au/Si 催化剂进行了形貌及电化学性能的表征. 结果表明, 该单层Pt 覆盖的Au/Si 催化剂对于甲醇的质量电催化活性是商业E-TEK(Pt/C)的8 倍,相比于不同层数的Pt, 单层覆盖时Pt 的利用率最高, 该单层Pt 负载Au/Si 催化剂对于抑制CO 的中毒的性能也比商业E-TEK(Pt/C)有明显的提高.     

Phytosynthesis of Au, Ag and Au-Ag bimetallic nanoparticles using aqueous extract and dried leaf of Anacardium occidentale

Present study reports a green chemistry approach for the biosynthesis of Au, Ag, Au-Ag alloy and Au core-Ag shell nanoparticles using the aqueous extract and dried powder of Anacardium occidentale leaf. The effects of quantity of extract/powder, temperature and pH on the formation of nanoparticles are studied. The nanoparticles are characterized using UV-vis and FTIR spectroscopies, XRD, HRTEM and SAED analyses. XRD studies show that the particles are crystalline in the cubic phase. The formation of Au core-Ag shell nanoparticles is evidenced by the dark core and light shell images in TEM and is supported by the appearance of two SPR bands in the UV-vis spectrum. FTIR spectra of the leaf powder before and after the bioreduction of nanoparticles are used to identify possible functional groups responsible for the reduction and capping of nanoparticles. Water soluble biomolecules like polyols and proteins are expected to bring about the bio-reduction.