以介孔氧化硅薄膜为模板电沉积合成新型纳米结构

首次以不同孔道结构的介孔氧化硅薄膜为模板,采用电化学沉积的方法,合成了金属铜和半导体氧化锌的纳米材料,并对其结构进行了表征．以六方孔道结构的介孔氧化硅模板获得了直径为7nm的金属铜纳米线阵列;以笼状体心立方孔道结构的模板获得了具有哑铃状形貌的铜单质纳米颗粒．对于氧化锌纳米结构,电化学沉积过程使得氧化锌完全填充氧化硅模板的孔道,分别得到了具有六方和体心立方介孔结构的Zn0/SiO2纳米复合物薄膜．     

疏水性有序介孔氧化硅薄膜的制备

采用溶胶−凝胶技术并结合蒸发诱导自组装工艺, 以三嵌段共聚物EO₂₀PO₇₀EO₂₀ (P123)为模板剂, 使用浸渍提拉法制备了有序介孔氧化硅薄膜, 并使用不同的表面修饰剂对薄膜进行表面处理, 制备了疏水性有序介孔氧化硅薄膜. 利用FT-IR、小角XRD、HRTEM分别表征薄膜的化学物种和孔结构, 探讨了热处理温度和老化时间对薄膜介孔结构的影响, 通过接触角测试研究薄膜的疏水性能, 考察了修饰剂种类、修饰浓度和修饰时间对薄膜疏水性的影响, 结果表明所制备的薄膜为高度有序的介孔氧化硅薄膜, 孔径大小约为8 nm|表面修饰对薄膜的有序性有一定影响, 经三甲基氯硅烷(TMCS)和g-氨丙基三乙氧基硅烷(KH-550)修饰后的薄膜具有很好的疏水性能, 接触角分别为112°和96°|修饰后薄膜的水汽稳定性良好, 仍能保持有序介孔结构, 孔径达7.5 nm, 接触角达93°.     

电化学沉积金纳米线结构及其电学特性

用电化学沉积方法,在有机介孔模板上制备出直径为90nm的金纳米线.透射电子显微镜(TEM)分析结果表明,纳米线表面光滑并呈单晶结构.去除有机模板的金纳米线阵列用扫描电子显微镜(SEM)测试,纳米线顶端呈平台状,直径分布均一.我们利用原子力显微镜(AFM)测量了金纳米线阵列的微观结构,得到与SEM相一致的结果.在大气和室温条件下,用导电AFM针尖在接触模式下测量了单根纳米线的轴向I-V特性曲线,其结果为金属性.     

电化学沉积金纳米线结构及其电学特性

用电化学沉积方法，在有机介孔模板上制备出直径为90 nm的金纳米线.透射电子显微镜（TEM）分析结果表明，纳米线表面光滑并呈单晶结构.去除有机模板的金纳米线阵列用扫描电子显微镜（SEM）测试，纳米线顶端呈平台状，直径分布均一.我们利用原子力显微镜（AFM）测量了金纳米线阵列的微观结构，得到与SEM相一致的结果.在大气和室温条件下，用导电AFM针尖在接触模式下测量了单根纳米线的轴向I－V特性曲线，其结果为金属性.     

介孔氧化钨电色薄膜的制备与性能研究

采用一种新的非离子型gemini表面活性剂结构导向模板, 成功制备了介孔氧化钨薄膜. 通过SAXRD, TEM和N₂吸附-脱附等方法考察薄膜的制备和微结构特性, 发现获得的产物具有三维蠕虫介孔结构, 比表面积可达145.5 m²• g^－1. 测定了该薄膜在无水高氯酸锂/碳酸丙烯酯电解质溶液中的循环伏安和电致变色性能, 并与无模板薄膜进行了对比研究. 研究表明, 由于具有更大的电化学活性比表面, 纳米介孔氧化钨薄膜表现出增强的电色性能, 在633 nm波长处的透过率调制幅度可达60%以上, 着色效率为51.7 cm²•C^－1.     

还原氧化石墨烯表面聚苯胺纳米阵列的制备及电化学电容性能

本文以阳极氧化铝(AAO)膜为模板,通过恒电位法在自组装还原氧化石墨烯(rGO)膜表面制备有序聚苯胺(PANI)纳米线阵列。通过拉曼光谱和场发射扫描电子显微镜分别对其结构和微观形貌进行了表征,并对PANI纳米线阵列的电化学电容性能进行了测试。结果表明,rGO膜表面可电沉积PANI,电沉积得到的PANI纳米线阵列具有比PANI薄膜材料更高的电容和比电容。     

激光刻蚀模板中电沉积特殊结构CIGS薄膜

本文利用激光刻蚀模板,在水溶液中电沉积制备金属铜薄膜,讨论了温度、电流、硫酸铜浓度对薄膜形貌的影响. 采用SEM对制备的铜薄膜进行表征,结果表明在沉积温度为30 ℃,沉积电流为4 A·dm^-2(表观工作电流密度),硫酸铜浓度在20 ~ 50 g·L^-1的水溶液中电沉积可以得到中空馒头状和开口碗状结构的铜薄膜. 利用激光刻蚀模板,在离子液体1-丁基-3-甲基咪唑三氟甲磺酸盐([BMI][TfO]) - 30 Vol%丙醇混合电解质中电沉积CIGS薄膜,研究了沉积电势、沉积时间对薄膜形貌的影响. SEM观察发现,在沉积电势为-1.8 V,沉积时间为1.5 h条件下电沉积可以得到近似柱状的簇状花束样的CIGS薄膜, 电沉积铜后再进一步电沉积CIGS,得到了均匀有序的鼓包柱状结构的Cu/CIGS复合薄膜. 用恒电势方波法对制备的薄膜真实表面积进行测试,计算结果表明,与无模板电沉积制备的CIGS薄膜相比,激光刻蚀模板法制备的Cu/CIGS复合薄膜的表面积提高了约8倍.     

孔径可调的介孔SiO2自支持薄膜的溶剂挥发诱导自组装合成与表征

以十六烷基三甲基溴化铵(CTAB)为模板剂, 正硅酸乙酯为硅源, 在弱酸性条件下利用溶剂挥发诱导自组装(EISA)合成出具有介孔结构的二氧化硅薄膜. 通过控制EISA过程中溶剂挥发的环境, 可在1.4~3.1 nm的范围内调节介孔结构的孔径. 实验表明, 较快的溶剂挥发速率有助于较大孔径的介孔结构生成. 用该方法合成的介孔薄膜具有蠕虫状孔道结构和良好的孔径均一性. 在外观上, 该薄膜具有均匀、透明和无缺陷等特点, 可以自支撑, 并且具有一定的韧性.     

氧化铝模板中Ag纳米线阵列的选择性生长

利用Ag离子与Br离子之间的化学沉积作用在孔隙中充满明胶的阳极氧化铝(AAO)模板中制备了AgBr/AAO纳米介孔复合材料.材料选择性曝光后,利用原位显影液对其进行化学显影,在AAO模板中选择性得到Ag纳米线阵列.实验结果表明:Ag纳米线是连续的、致密的,且具有多晶结构,充满了曝光部分的模板孔隙.本文还对影响Ag纳米线选择性生长的因素进行了简单讨论.     

介孔TiO_2薄膜光波导共振传感器对苯并(a)芘的探测灵敏度

采用溶胶-凝胶分子模板法在覆金的玻璃基底上制备了厚度约为295 nm的介孔TiO_2薄膜,再经表面化学修饰形成表面疏水的光波导共振(OWR)传感芯片,用于探测水中苯并(a)芘。利用Kretschmann棱镜耦合结构观测到OWR芯片在可见-近红外波段只有一个共振波谷,基于相位匹配条件确定了该共振波谷对应于二级横磁导模(TM2);进一步利用Fresnel理论并结合Bruggeman介电常数近似方程对实验测得的导模共振波长进行拟合,得出介孔TiO_2薄膜的多孔度约为0.4;利用疏水介孔TiO_2薄膜OWR传感芯片对水中苯并(a)芘小分子进行了原位和离位探测,结果表明离位探测灵敏度比原位探测高2倍多,其最低检测限约为100 nmol·L~(-1);对比实验指出OWR传感芯片的多孔结构和疏水化处理都有助于提高芯片对苯并(a)芘的探测灵敏度。研究表明这种介孔TiO_2薄膜OWR传感芯片具有良好的稳定性,可重复利用。     

Usefulness of Mesoporous Silica as a Template for the Preparation of Bundles of Bi Nanowires with Precisely Controlled Diameter Below 10 nm

The reduction of the diameter of Bi nanowires below 10 nm has been an important target because of the theoretical prediction with regard to significant enhancement in thermoelectric performance by size reduction. In this study, we have demonstrated the usefulness of mesoporous silica with tunable pore size as a template for the preparation of thin Bi nanowires with diameters below 10 nm. Bi was deposited within the templates through a liquid phase deposition using hexane and 1,1,3,3‐tetramethyldisiloxane as a solvent and reducing agent, respectively. Bundles of thin Bi nanowires with non‐crystalline frameworks were successfully obtained after the template removal. The diameter was precisely controlled between about 6 nm and 9 nm. The judicious choices of mesoporous silica and deposition conditions are critical for the successful preparation. The reliable formation of such thin Bi nanowires reported here opens up exciting new possibilities.     

氨基功能化有序介孔Si02薄膜组装Au纳米粒子复合材料的可调色散性质

以聚环氧乙烷-聚环氧丙烷-聚环氧乙烷(P123)为模板剂,采用共溶胶的蒸发诱导自组装方法制备了氨基功能化介孔SO2薄膜,然后利用氯金酸(HAUCl4)与介孔SiO2薄膜孔道内壁的氨基之间的中和反应组装Au纳米粒子,制备得到Au/SiO2纳米复合材料.用TEM,XRD和UV-Vis光谱对材料进行了测试.结果表明,无水乙醇...     

模板合成法制备金纳米线的研究

近年来,利用化学和物理方法制备各种高度有序的纳米结构材料已经成为学术界的研究热点之一．其中,在特定的模板中沉积各种材料而构建纳米点阵的方法,具有制备简便,成本较低等优点,而且在尺度上可以突破刻蚀技术的局限性,具有广泛的应用前景［１］．常用的模板有阳极氧化多孔铝（ＡＡＯ）、多孔硅和聚合物等,其中ＡＡＯ模板具有耐高温,绝缘性好,孔洞分布均匀有序,而且大小可控等特点［２］,是使用较为广泛的一种．利用阳极氧化铝为模板,采用电化学方法［３～７］或压差注入法［８］制备有序的纳米粒子点阵,已经在润滑［９］、电…     

Synthesis of ultrahigh-density ordered arrays of metallic nickel nanowires in mesoporous silica films

Two-dimensional (2D) mesoporous silica films were employed as a template to fabricate ultrahigh-density ordered arrays of metallic nickel nanowires via electroless deposition.     

Gold electroless reduction in nanosized channels of thiol-modified SBA-15 material

A new procedure for the preparation of high aspect ratio Au nanowires utilizing gold electroless reduction in the hexagonally ordered, thiol-modified nanosized channels of the SBA-15 material is reported. Two different Au precursors were adsorbed onto pedant thiol groups, covalently bonded to the mesoporous silica surface, and used as seeds to grow extended Au nanostructures by treatment in Au electroless reduction bath. It is shown that the dimensions and the assembly of the Au seeds are important parameters for the subsequent electroless reduction process. The [AuCl4]- ions complexed to the TOAB molecules assembled on the thiol-modified mesoporous surface of the SBA-15 material are suitable precursors for the subsequent gold electroless reduction. The resulting structures are several micrometer long Au nanowires with uniform diameters of about 5 nm, having large single-crystalline domains. The TEM results clearly show that the growth of the Au nanowires is templated by the channel structure of the SBA-15 material.     

Synthesis of confined Ag nanowires within mesoporous silica via double solvent technique and their catalytic properties

Ag nanowires within the channels of mesoporous silica have been successfully synthesized via a double solvent technique, in which n-hexane is used as a hydrophobic solvent to disperse mesoporous silica and an AgNO(3) aqueous solution is used as a hydrophilic solvent to fill mesochannels. The morphology of the obtained Ag (nanowires, nanoparticles or nanorods) can be controlled by adjusting the concentration of AgNO(3) solution and the template pore size. HRTEM images demonstrate extensive Ag nanowires with several to tens of hundreds nanometers in length are deposited along the long axis of mesochannels when the atomic AgNO(3)/Si ratio is 0.090. When the atomic AgNO(3)/Si ratio is 0.068 or 0.11, there is a combination of Ag nanoparticles and nanowires; nanoparticles are mainly formed when the atomic AgNO(3)/Si ratio is higher than 0.14. Further, the catalytic results of the oxidation of styrene show that styrene oxide and benzaldehyde are the main products of the reaction, and the morphology and diversity of Ag in Ag/mesoporous silica composites have an effect on the conversion of styrene and selectivity of styrene oxide.     

Magnetic cobalt nanowire thin films

Two-dimensional (2D) and three-dimensional (3D) magnetic cobalt nanowire thin films with tunable 3-10 nm wire diameters have been electrodeposited using mesoporous silica templates containing 2D hexagonal or 3D cubic pore channels. As compared to bulk cobalt films, the cobalt nanowire thin films exhibit enhanced coercivities and controllable magnetic anisotropy through tuning of the mesostructure and dimension of the nanowires. Such novel magnetic nanowire thin films may provide a new platform for high-density information storage applications.     

An observation of palladium membrane formation on a porous stainless steel substrate by electroless deposition

The membranes made of palladium and its alloys are used for the extraction of high quality hydrogen from a mixture of gases. Most of recent research is focused on the development technologies for depositing a durable ultra-thin palladium membrane on a porous substrate in order to assure a good mechanical support and maximize the flux of hydrogen permeation. The formation of a palladium membrane deposited on a porous stainless steel substrate by an electroless process is recorded and described in this paper. The palladium deposition progress around the pore area at the surface of the substrate in the initial stages is illustrated. A bridge model is presented to describe the membrane formation around the pore area of the substrate. This model, together with the micrographs showing the deposition progress on the pore areas, will lead to the control of the deposition process for a membrane fabrication as well as the design and modification of a substrate.     

Palladium coated porous anodic alumina membranes for gas reforming processes

Nanostructured ceramic membranes with ultrathin coatings of palladium metal have been demonstrated to separate hydrogen gas from a gas mixture containing nitrogen with 10% carbon dioxide and 10% hydrogen at temperatures up to 550 °C. The mechanically robust and thermally durable membranes were fabricated using a combination of conventional and high-efficiency anodisation processes on high purity aluminium foils. A pH-neutral plating solution has also been developed to enable electroless deposition of palladium metal on templates which were normally prone to chemical corrosion in strong acid or base environment. Activation and thus seeding of palladium nuclei on the surface of the template were essential to ensure uniform and fast deposition, and the thickness of the metal film was controlled by time of deposition. The palladium coated membranes showed improved hydrogen selectivity with increased temperature as well as after prolonged exposure to hydrogen, demonstrating excellent potential for gas separation technologies.     

Macroporous Au materials prepared from colloidal crystals as templates

In this paper, we reported the preparation of macroporous Au materials using organic colloidal crystals as templates and their catalytic activity for electroless copper deposition. The poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)) copolymer colloids were deposited in an orderly manner onto the silicon surface, together with the infiltration of the Au nanoparticles into the interspaces of the colloids. The formed hybrid colloidal crystal subsequently was sintered at approximately 550 degrees C to remove the organic components fully to obtain a macroporous Au framework with three-dimensional ordered porous structure. The pore diameter was around 310 nm and almost monodisperse. It was demonstrated that the macroporous Au materials exhibit catalytic activity and can induce electroless copper deposition.