Si3N4/Si表面Si生长过程的扫描隧道显微镜研究

利用原位扫描隧道显微镜和低能电子衍射分析了Si的纳米颗粒在Si₃N₄/Si(111)和Si₃N₄/Si(100)表面生长过程的结构演变.在生长早期T为350—1075K范围内,Si在两种衬底表面上都形成高密度的三维纳米团簇,这些团簇的大小均在几个纳米范围内,并且在高温退火时保持相当稳定的形状而不相互融合.当生长继续时,Si的晶体小面开始显现.在晶态的Si₃N₄(0001)/S 关键词： 氮化硅 扫描隧道显微镜 纳米颗粒     

蛋膜仿生制备纳米硫化锌

以鸡蛋膜作为生物载体,利用蛋膜上周期性分布的大分子与无机前驱体离子之间的螫合作用和电荷作用,引导和控制无机微晶在蛋膜载体上的形成、聚集和分布,成功制备了分散度好、形貌规整的平均粒径为95nm的ZnS纳米团簇.     

双金属催化剂催化间苯氧基苯甲醛加氢反应

利用硼氢化钠还原含其它金属盐的氯铂酸形成双金属合金纳米催化剂.Ru和Co的加入能提高催化剂的活性,当Pt/Ru摩尔比为5∶1、Pt/Co摩尔比为7∶1时,双金属协同效应最明显;Cu、Au、Ni的加入不同程度的降低了催化剂的活性.对Pt/Ru和Pt/Co体系,PVP的含量和反应温度都对催化反应的活性有影响.     

Electrocrystallization: Nucleation and growth of nano-clusters on solid surfaces

Electrocrystallization phenomena are considered and basic thermodynamic and kinetic concepts related to the electrochemical nucleation and growth are defined and discussed in details. Theoretical and experimental findings related to the stationary and non-stationary nucleation kinetics, growth of single two-and three-dimensional crystals as well as underpotential deposition phenomena and spatial distribution of clusters are reviewed and the reader is referred to suitable sources of reliable information on the most important subjects concerned. Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 6, pp. 669–698. The text was submitted by the author in English.     

Si_3N_4/Si表面Si生长过程的扫描隧道显微镜研究

利用原位扫描隧道显微镜和低能电子衍射分析了Si的纳米颗粒在Si3N4 /Si(111)和Si3N4 /Si(10 0 )表面生长过程的结构演变 .在生长早期T为 35 0— 10 75K范围内 ,Si在两种衬底表面上都形成高密度的三维纳米团簇 ,这些团簇的大小均在几个纳米范围内 ,并且在高温退火时保持相当稳定的形状而不相互融合 .当生长继续时 ,Si的晶体小面开始显现 .在晶态的Si3N4 (0 0 0 1) /Si(111)表面 ,Si的 (111)小面生长比其他方向优先 ,生长方向与衬底Si(111)方向一致 .最后在大范围内形成以 (111)为主的晶面 .相反 ,在非晶的Si3N4 表面 ,即Si3N4 /Si(10 0 ) ,Si晶体的生长呈现完全随机的方向性 ,低指数面如 (111)和 (10 0 )面共存 ,但它们并不占据主导地位 ,大部分暴露的小面是高指数面如 (113)面 .对表面生长过程进行了探讨并给出了合理的物理解释     

Weakly bound buffer layer as a template for metallic nano-clusters growth and film laser-patterning

Growth of metallic nano-clusters and control over their size are critically important for catalysis. Development of film patterning procedures at the nanometer scale has significant impact on future lithography. In this work, we present an approach to grow metallic nano-clusters and control their size using a weakly bound buffer layer as an intermediate substance and a template to control the clusters size at the range 1-15 nm.The buffer layer was further employed to create a pattern based on a selective laser ablation procedure. A thicker metallic film deposited on top of pre-patterned buffer layer has been demonstrated as a novel patterning technique at the sub-micron to nanometer scale employing a single laser pulse. The thermal stability of metallic structures prepared this way has been studied at temperature up to 1000 K.     

单分散水溶性金纳米团簇的制备及表征

采用改进的Brust方法,用硼氢化钠还原氯金酸,并以巯基丁二酸(MSA)、氮乙酰基半光胺酸(NAC)作为包裹剂,成功制备了单分散的水溶性金纳米团簇。高分辨透射电镜(HRTEM)结果表明,增大硫醇与氯金酸的比例并增加氯金酸的初始浓度,有利于得到尺寸更小的金纳米粒子。当氯金酸的浓度(C_Au)为9.3 mmol·L^-1,C_Au:C_S为1:30时,得到了直径约为1 nm、标准偏差为0.2 nm的Au@MSA纳米团簇。结合紫外(UV)、热重(TG)和X射线光电子能谱(XPS)分析结果,可以推测出单分散金纳米簇的化学式为[Au₃₈(MSANa)₂₆]或[Au₃₉(MSANa)₂₇]。     

Characterization of Au nano-cluster formation on and diffusion in polystyrene using XPS peak shape analysis

XPS peak shape analysis is used as a novel and nondestructive method to study Au nano-cluster growth mechanism on polystyrene (PS) as a function of deposition as well as diffusion and distribution of the nano-clusters in PS as a function of subsequent annealing at temperatures in the range from room temperature to above the glass transition temperature of PS. The Au nano-cluster size and density are determined for four different amounts of Au deposition. It is shown that this nondestructive method can give all mentioned information on such a metalized polymer without the need for any other complimentary and time consuming technique such as AFM, TEM and the destructive technique XTEM. Thus this method is suitable to monitor and control the degree of intermixing of metal nano-clusters and polymers which is of high technological interest.     

基于铜纳米簇的硝酸根微传感器的研究

基于循环伏安扫描(CV)的电化学沉积方法制备出多孔性纳米簇状结构铜膜,结合采用微机电系统(Micro electro mechanical systems,MEMS)技术制备的微电极芯片,研制出用于NO3-检测的安培型微传感器。考察该微传感器对NO3-的响应性能,在6.25~300mmol/L浓度范围内,灵敏度为0.0526mA/(mmol/L),线性度99.93%;在300~3500mmol/L浓度范围内,灵敏度为0.0353mA/(mmol/L),线性度99.18%。与文献报道相比,该传感器表现出更高的灵敏度。考察水体中常见的NO2-,Cl-,HPO42-/PO43-,SO42-,HCO3-/CO23-,Na+和K+等离子对该传感器的干扰性能,传感器表现出较好的抗干扰性能。采用该微传感器对实际水样进行测试,测试结果与具有权威资质的测试公司的测试结果之间具有一定的相关性。实验结果表明,采用循环伏安沉积方法在微电极表面制备的纳米簇状结构的铜敏感膜,比表面积大,催化活性高,对NO3-表现出了很好的敏感特性和选择性,适用于对微量NO3-的检测。     

氧化锌纳米簇-金纳米颗粒-壳聚糖复合膜修饰电极用于示差脉冲伏安法测定吗啡

将制备的氧化锌纳米簇和金纳米颗粒分散在壳聚糖中并滴涂在玻碳电极表面,制备了氧化锌纳米簇-金纳米颗粒-壳聚糖复合膜修饰电极(Au-ZnO-CHIT/GCE)。采用循环伏安法研究了吗啡在修饰电极上的电化学行为。结果表明:吗啡在该修饰电极上出现了一个氧化峰,提出了用示差脉冲伏安法测定吗啡的方法。吗啡浓度在5.3×10-6~6.5×10-4mol.L-1范围内与氧化峰电流呈线性关系,检出限(3S/N)为1.8×10-6mol.L-1。修饰电极用于尿液中吗啡的测定,回收率在80.0%~99.6%之间。