Ni纳米线阵列的电化学组装及磁性能研究

利用二次氧化法制备了多孔阳极氧化铝(AAO)模板,通过恒电位沉积法在模板内组装了Ni纳米线阵列。采用SEM、TEM、SAED、EDS和VSM等检测技术对填孔过程、阵列形貌、结构和磁性能进行了分析和表征。结果表明,Ni纳米线在纳米孔中的生长过程经历四个阶段,填孔终止时间控制在第三阶段。适宜AAO模板中Ni纳米线沉积的电位为-0.9 V,pH为3.5。Ni纳米线是沿着(111)方向生长的单晶结构。当外磁场平行或垂直Ni纳米线阵列时,在磁场强度周期变化下,测量纳米线阵列磁滞现象的闭合磁化曲线,Ni纳米线阵列在平行和垂直两个方向的磁性不同,剩余磁化强度Mr与饱和磁化强度Ms之比分别为0.282和0.055,其矫顽力是293 Oe、100 Oe。     

铂/介孔碳纳米线复合材料的制备及电催化性能研究

以碳材料为载体的催化剂在电催化领域得到广泛关注,采用双模板法技术,将200 nm孔径的阳极氧化铝模板与嵌段共聚物模板F127相结合,利用气相还原和高温碳化技术,合成了以介孔碳纳米线为载体的含铂量为10 wt%的铂/介孔碳纳米线复合材料。并对其在甲醇的电氧化性能方面进行了考察。结果表明,由于介孔碳纳米线的存在,增加了材料的有效比表面积,使铂的有效催化能力显著提高。     

多孔阵列聚合物模板及铜微/纳米线的可控制备

金属纳米线阵列材料是最具潜力的高时空分辨X射线强辐射源材料之一。采用集束热拉伸法,通过尺寸设计和参数控制,制备了包埋高度取向的聚苯乙烯微纳米线有序阵列结构的聚甲基丙烯酸甲酯复合丝,通过后续包埋、切片、溶解等处理过程,获得孔径/孔间距约为1∶1的多孔聚甲基丙烯酸甲酯模板。通过光学显微镜和扫描电镜(SEM)观察,二级模板的孔径及孔间距尺寸约十几微米,三级模板的孔径及孔间距尺寸约500 nm。利用电化学沉积技术在制备的模板上成功地生长了铜微/纳米线,铜纳米线长度超过10μm。该研究为特定尺寸要求的金属微纳米线阵列的制备提供了技术支持。     

Ni_(79)-Fe_(21)合金纳米线的电化学制备与表征

以多孔氧化铝为模板,采用控电位沉积方法制备了Ni-Fe纳米线及其阵列。能谱分析表明,纳米线组成为Ni79-Fe21。X-射线衍射测试表明,Ni-Fe纳米线呈面心立方Ni固溶体结构。磁滞回线测试表明,控电位制备的Ni-Fe纳米线阵列具有良好的软磁性能,500℃退火处理后,Ni-Fe合金纳米线具有硬磁性。     

控电位法制备CdSe纳米线阵列及其性能研究

以SeO2为硒源,以阳极氧化铝为模板,采用电化学方法对SeO2在碱性电解液中的还原过程进行了分析,确定了控电位制备CdSe纳米线的沉积电位和镀液组成,并分析了其沉积机理。在此基础上,以阳极氧化铝为模板,通过控电位法成功获得CdSe纳米线阵列。采用扫描电子显微镜、透射电子显微镜和X-射线衍射对所制备的材料进行了形貌和结构表征。扫描电镜形貌分析表明,CdSe纳米线阵列高度有序、直径均一;直径约100 nm,与模板孔径一致。X-射线衍射测试表明,所制得的CdSe纳米线为立方晶型。光电性能测试表明,CdSe纳米线阵列电极的开路电位差值为324.8 mV,高于CdSe薄膜(125.5 mV);光催化降解罗丹明B测试表明,5 h后,CdSe纳米线的降解率达94.29%,强于CdSe薄膜(52.03%)。     

模板法交流电沉积铜纳米线阵列及其表征

先通过二次阳极氧化法制备多孔阳极氧化铝膜模板,再采用交流电沉积法将Cu金属填入模板的纳米孔洞中得到铜纳米线阵列。分别采用扫描电镜、透射电镜和X射线衍射仪对Cu纳米线阵列的形貌和晶体结构进行表征。结果表明,多孔氧化铝模板的孔洞排布致密、均匀而有序。交流电沉积所得Cu纳米线为单晶结构,直径为60~90 nm,长度为0.5~4.0μm。     

以多孔氧化铝为模板钴纳米线阵列的制备

以多孔氧化铝为模板,采用交流电沉积的方法制备了钴纳米线阵列膜.采用扫描电子显微镜(SEM)对电沉积钴纳米线前后的多孔氧化铝模板的形貌进行表征,通过透射电子显微镜(TElM)观察钴纳米线的表面形貌.结果表明:金属钴沉积到多孑L氧化铝模板的纳米孑L中,钴纳米线的平均直径约为50n/n,与氧化铝模板的孔径相一致.     

铜金属纳米线的制备及其图案化

采用电化学沉积法在孔径为200nm的阳极氧化铝膜AAO模板中成功制备了Cu金属纳米线阵列、结合紫外线光刻法组装了图案化铜纳米线阵列.电化学沉积法可通过控制沉积时间来获得具有不同长径比的铜纳米线阵列;图案化的纳米线排列规整,高度有序;且纳米线组成的形状与掩膜相同.     

聚苯胺纳米线阵列的电化学组装研究

利用二次氧化法制备了多孔阳极氧化铝模板,通过控制电位聚合技术在阳极氧化铝模板内组装了聚苯胺纳米线阵列。采用扫描电子显微镜、透射电子显微镜和能谱仪等检测技术对填孔过程和阵列的形貌、结构进行分析和表征。结果表明,苯胺在纳米孔中的聚合过程经历四个阶段,填孔终止时间控制为第二阶段结束时间。阳极氧化铝模板中苯胺聚合适宜的电位为1.0V,pH为2.5。聚苯胺纳米线的直径均匀,约为70nm,与模板孔径基本一致,为非晶结构。     

铂钴合金修饰的乙酰胆碱酯酶生物传感器的研制铂钴合金修饰的乙酰胆碱酯酶生物传感器的研制

采用恒电位沉积技术,通过聚碳酸酯模板直接在玻碳电极上制得铂钴合金纳米线阵列,将其固定酶制成乙酰胆碱酯酶(AChE)生物传感器,用于抑制剂有机磷农药辛硫磷的测定。考察了电位、pH值、底物浓度等条件对传感器测定辛硫磷的影响。在优化条件下,检测辛硫磷的线性范围为7.00×10-4~8.20 mmol·L-1,检测下限为2.35×10-4mmol·L-1。该传感器具有操作简单、检测范围宽、灵敏度高等优点,用于蔬菜、水果中有机磷农药的测定,效果良好。     

多元氧化物纳米丝阵列的电泳沉积

以多孔氧化铝(porous alumina)为模板,用电泳沉积技术组装了高度有序的钛酸钡(BaTiO3)、钛酸锶(SrTiO3)、锆钛酸铅(lead zirconate titanate,PZT)等多元氧化物纳米丝阵列.用扫描电镜(scanning electron microscope,SEM)、透射电镜(transmission electron microscope,TEM)、选区电子衍射(selected area electron diffraction,SAED)、X射线衍射(x-ray diffraction,XRD)等手段表征多元氧化物纳米丝阵列.SEM照片显示:所得纳米丝连续、致密,纳米丝直径略小于模板孔径且模板填充率很高.XRD和SAED显示:纳米丝为多晶钙钛矿型结构.因此,电泳沉积法是一种很有发展前途的制备氧化物纳米丝阵列的方法.     

溶胶凝胶-模板法制备一维金纳米材料

采用HAuCl4水溶液和柠檬酸三钠水溶液制备了金溶胶,利用多孔氧化铝(AAO)为模板,采用浸泡金溶胶-凝胶的方法,制备了一维金纳米材料。利用扫描电镜、透射电镜、选区电子衍射、X射线衍射对产物进行了表征。结果表明通过控制金胶的浓度和模板的浸泡时间,可分别获得管状和线状结构的一维金纳米材料,其直径为200 nm左右,长度可达几十微米,由细小的金晶粒组成。     

Synthesis of mesoporous Si/SiC with three-dimensional structure derived from C/silicalite-1 via magnesiothermic reduction

C/silicalite-1 composites were successfully synthesized by using industrial silica sol as silica source and multiwalled carbon nanotube (MWCNTs) as carbon source under hydrothermal method. Then, C/silicalite-1 composites were transformed into mesoporous Si/SiC through magnesiothermal reduction at relatively low temperature (650 °C). The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and Brunauer–Emmett–Teller analysis (BET). The XRD patterns and TEM micrographs exhibit that C/silicalite-1 composites are transformed into Si/SiC. The SEM images exhibit that Si/SiC keeps the three-dimensional structure of silicalite-1. BET analysis shows that the specific surface areas and mesoporous distribution of Si/SiC are 274 m²/g and 4.69 nm, respectively.     

弱酸性条件下SBA-16型二氧化硅介孔材料的合成与表征

引言 有序介孔材料由于具有较大的比表面积、均一可调的孔径(2～50 nm)、规则可控的形貌、较高的热稳定性和耐水解性等性能,在分离、吸附、催化、生物材料、信息材料、碳纳米管制备等领域有着广泛应用[1-3].     

Synthesis of single-crystalline lanthanum hexaboride nanowires by Au catalyst

Lanthanum hexaboride (LaB₆) nanowires have been successfully fabricated by the facile catalytic reaction of lanthanum (La) powders, and gas mixture of boron trichloride (BCl₃), hydrogen and argon, where Au was used as the catalyst. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected-area electron diffraction (SAED) were used to characterize the composition, morphology and structure of the samples. Single crystal column-shape LaB₆ nanowires were obtained. It is expected that LaB₆ nanowires can provide thermionic emission, field-induced emission, and thermal field-induced emission of electrons for TEM, SEM, flat panel displays, as well as many electronic devices that require high-performance electron source.     

An organic/inorganic hybrid mesoporous silica membrane: preparation and characterization

An organic/inorganic hybrid mesoporous silica membrane composed of mesoporous silica materials inside the channels of polycarbonate filtration membrane (PC) was synthesized by using aspiration-induced infiltration method, and the surfactant in as-prepared membrane was removed by employing template-extraction method. The obtained materials were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD),transmission electron microscopy (TEM) and N₂ adsorption–desorption measurement. The SEM images and EDS elemental analyses show that as-synthesized materials in PC are one-dimensional silica rods estimated as 200 nm in diameter and 9 μm in length. Moreover, the results of XRD, TEM and N₂ adsorption–desorption analysis clearly demonstrate that such silica rods are mesoporous materials with two-dimensional hexagonal mesostructure and the average mesopore diameter is about 3.0 nm. In addition, the porosity of organic/inorganic hybrid mesoporous silica membrane was further examined by molecule permeation. It is found that small molecule, such as rhodamine B, can transport across the membrane, but relatively large molecule, such as horse radish peroxidase, can not transport across the membrane, indicating that it is size-selectivity of such a membrane for molecule permeation, which has the potential application in the molecule filters to separate bio-macromolecule from small molecule.     

CoPt_3纳米线阵列的制备及特性研究

在具有纳米级孔洞的多孔氧化铝模板上,用电化学方法成功地制备了CoPt3纳米线有序阵列复合膜。分别用透射电子显微镜(TEM)、选区电子衍射(SAED)、X射线衍射(XRD)、振动样品磁强计(VSM)和SQUID对样品进行了测试与表征。形貌观察和物相分析表明,模板中的CoPt3纳米线构成的阵列,排列均匀有序,长约1.5微米,直径35纳米;而纳米线中的CoPt3为L12无序结构。磁性研究表明,纳米线的无序晶体结构决定了纳米线阵列弱的磁晶各向异性;同时纳米线中部分小晶粒在400K左右表现出顺磁性,导致纳米线阵列居里温度的下降。比较低温和室温下的磁滞回线,低温下有大的矫顽力,从另一方面证明纳米线中的小晶粒确实存在相转变。     

Ordered Mesostructured CdS Nanowire Arrays with Rectifying Properties

Highly ordered mesoporous CdS nanowire arrays were synthesized by using mesoporous silica as hard template and cadmium xanthate (CdR₂) as a single precursor. Upon etching silica, mesoporous CdS nanowire arrays were produced with a yield as high as 93 wt%. The nanowire arrays were characterized by XRD, N₂ adsorption, TEM, and SEM. The results show that the CdS products replicated from the mesoporous silica SBA-15 hard template possess highly ordered hexagonal mesostructure and fiber-like morphology, analogous to the mother template. The current–voltage characteristics of CdS nanoarrays are strongly nonlinear and asymmetrical, showing rectifying diode-like behavior.     

Deposition of Pd into mesoporous silica SBA-15 using supercritical carbon dioxide

Pd was deposited into mesoporous silica SBA-15 using supercritical CO₂ (scCO₂). Palladium hexafluoroacetylacetonate [Pd(hfac)₂] was dissolved in scCO₂ and impregnated into the support at very mild conditions, 40 °C and 85 bar. Then the organometallic precursor was reduced with H₂ in the CO₂ mixture or, after depressurization, in pure H₂. Materials were characterized by TGA, XRD, TEM, SEM, EDX, ICP-OES and N₂-adsorption experiments. Pd nanoparticles evenly distributed into the support (1-3 mol% Pd by ICP-OES) are only obtained when the reduction is performed in pure H₂. Cluster size is limited in two dimensions by the pore size of the support but clusters grow larger with increasing impregnation time and turn into small nanowires. The catalytic activity of the Pd/SiO₂ composite material was confirmed following the reduction of 4-nitrophenol to 4-aminophenol in water by UV-vis spectroscopy.     

Co/Zn-Grafted Mesoporous Silica Nanoparticles Catalyzed Cyclohexanimine Oxidation under UV Irradiation: High Performance Ozonation Process

Silicon - A new series of cobalt/zinc-grafted mesoporous silica nanoparticles (CZ-MSN) catalysts were synthesized and characterized using FTIR, SEM, TEM, XRD and nitrogen adsorption-desorption. The...