均匀沉淀法制备不同粒径的纳米Cu（OH）2

以无水硫酸铜和氢氧化钡为原料,采用均匀沉淀法研究了不同粒径纳米Cu（OH）2的制备,考察了搅拌温度、硫酸铜溶液浓度等反应条件对纳米Cu（OH）2粒径的影响。实验结果表明,用均匀沉淀法可以制备出不同粒度的纳米Cu（OH）2颗粒。反应条件对纳米Cu（OH）2的粒径有显著影响,反应温度越高,纳米粒子的粒径越小;硫酸铜溶液的浓度越高,纳米粒子的粒径越大。     

水解-刻蚀法制备CuMnO2纳米片阵列薄膜及其催化性能

以CuO纳米片阵列为前体,通过水解-刻蚀法在水热条件下制备出了CuMnO₂纳米片阵列薄膜。由于同时存在具有催化活性的Cu（Ⅰ）和Mn（Ⅲ）,CuMnO₂纳米片阵列薄膜对催化H₂O₂氧化降解亚甲基蓝（MB）溶液具有优异的效果。进一步放大实验表明,该CuMnO₂薄膜具有稳定的催化性能。基于基底生长的薄膜催化剂能够解决粉体催化剂容易团聚、分离回收困难和容易造成二次污染等问题,在染料废水处理方面具有很好的工程应用前景。     

Cu2O/CuO/Cu电极光电催化还原CO2

利用表面氧化法在铜基底上制备CuO纳米带(CuO NRs),通过电化学法将Cu_2O沉积到CuO NRs上,得到复合电极Cu_2O/CuO/Cu。借助X射线衍射(XRD)、透射电子显微镜(TEM)对Cu_2O/CuO/Cu复合电极的结构进行了表征。通过线性扫描伏安法(LSV)、光电流-时间测试、电化学阻抗测试对Cu_2O/CuO/Cu复合电极光电催化CO_2性能进行了考察。借助变色酸分光光度法来测定CO_2光电还原产物。结果表明:氧化铜在铜基底上呈纳米带生长;复合电极Cu_2O/CuO/Cu对CO_2有较强的光响应性,表现出优异的光电催化性能;Cu_2O/CuO/Cu复合电极光电催化还原CO_2的主要产物是甲醇,在0.1 mol/L NaHCO_3溶液中光电催化6 h后,甲醇质量浓度为32.2mg/L。     

铜表面硬脂酸自组装膜的制备及耐腐蚀性能

应用自组装技术在Cu(OH)2纳米柱/CuO微花阶层结构表面制备硬脂酸自组装膜(SAM),运用电化学阻抗谱探讨了形成自组装膜的较佳浓度和自组装时间,通过极化曲线和循环伏安法考察了硬脂酸自组装膜在0.1 mol/L NaCl溶液中对铜电极的缓蚀性能.结果表明,当CuO/Cu(OH)2电极在8 mmol/L硬脂酸溶液中自组...     

YBa_2Cu_3O_(7-δ)纳米点的制备及其对超导磁通钉扎性能的影响

为了提高YBa_2Cu_3O_(7-δ)(YBCO)超导薄膜在磁场作用下的载流能力,首先使用YBCO前驱体溶液在LaAlO_3单晶基板上制备了钉扎中心。通过改变YBCO前驱体溶液的浓度,改变基板上YBCO钉扎中心的尺寸和密度。然后在YBCO纳米点上表面外延生长YBCO薄膜。分析了YBCO在纳米点上生长膜层的取向、织构,研究了YBCO纳米点的磁通定扎效果。结果表明:使用0.1 mol/L的低浓度YBCO前驱体溶液可以获得细小的,尺寸约为30 nm且分布均匀的YBCO纳米点;在其上沉积的YBCO薄膜具有良好的织构,其磁通钉扎效果最明显,表现出了良好的抗磁场效应。随着YBCO前驱体浓度的增加,钉扎中心的尺寸逐渐增大,对YBCO厚膜的磁通钉扎效果逐渐衰减。不同浓度YBCO前驱体制备的纳米点对YBCO厚膜的外延生长没有影响。     

吸附相反应结晶过程的模型与数值模拟

针对吸附相反应技术制备CuO/SiO2的过程,构建了体系中反应物的扩散传递、反应、成核、生长等过程的模型,通过深入剖析过程的机理,对复杂的微分方程组进行解耦。在MATLAB平台上数值求解模型,得到了本体相、吸附相中各组分的浓度随时间的变化以及CuO粒子的生长过程,为深入了解过程的内在规律提供了依据。结果表明:吸附层中Cu(OH)2的浓度迅速上升然后趋于定值,而本体相中的Cu(OH)2浓度一直维持在很低的水平;结晶过程的成核时间短,且最后获得了粒径窄分布的小粒径粒子。     

恒电流法制备Cu2O/TiO2复合纳米管阵列异质结光电极

通过在含F-离子的电解液中阳极氧化Ti薄片基底制备了TiO2纳米管阵列,随后通过恒电流沉积的方法在在TiO2纳米管阵列顶部原位电沉积了Cu2O纳米颗粒。场发射电子扫描显微镜显示TiO2纳米管这列被成功制备,通过恒电流电化学沉积后,TiO2纳米管阵列顶部出现大量纳米颗粒物质,并且随着沉积时间的延长,可以控制沉积物的量。通过X-射线衍射谱的特征衍射谱图我们可以发现TiO2锐钛矿的衍射峰以及相对较弱的Cu2O衍射峰,这说明Cu2O晶体的结晶度不高。在能谱（EDS）图中我们可以发现Ti、Cu、O三种元素,结合XRD以及FE-SEM结果我们可以指出,通过恒电流法确实可以在TiO2纳米管阵列顶部原位沉积Cu2O纳米颗粒。     

离子液体中CuO纳米棒的制备与结构表征

以离子液体1-丁基-3-甲基咪唑氯([bm im]C l)为介质,以Cu(CH3COO)2.2H2O和NaOH为原料,采用溶剂热反应法,制备了一维CuO纳米棒。用XRD、FESEM和TEM/SAED对产物进行了结构和形貌表征,结果表明:经140℃恒温反应20 h,可制备出CuO纳米棒,其长度约为70~100 nm,直径约为15~20 nm,两端为半球型;离子液体作为软模板剂,引导纳米晶体沿[010]方向生长。FTIR和TG分析表明:离子液体修饰在CuO纳米棒的表面,从而有效地阻止了CuO纳米棒的团聚。应用紫外-可见吸收光谱估测CuO纳米棒的带隙能量为2.64 eV。离子液体在反应中发挥了助溶剂、模板剂和修饰剂的三重作用。     

棒状形貌纳米氧化锌的合成及其应用

以六水硝酸锌和氨水-氢氧化钠为原料,采用液相沉淀法制备出氧化锌纳米棒。研究了氨水的初始浓度、滴加速度以及加热方式对纳米氧化锌形貌和尺寸的影响。结果表明：在氨水初始浓度为5%（质量分数）、滴加速度为60 g/h,并采用两段加热（成核生长温度为60 ℃、陈化温度为80 ℃）的方式,合成的纳米氧化锌呈棒状形貌,分散均匀,长径比达到11。纳米氧化锌对大肠杆菌具有很好的抑菌效果。水性聚氨酯中加入1.5%（质量分数）的棒状形貌纳米氧化锌后,可吸收250～400 nm的紫外线,拉伸强度从2.7 MPa增加到4.5 MPa。     

水解-刻蚀法制备CuMnO_2纳米片阵列薄膜及其催化性能

以Cu O纳米片阵列为前体,通过水解-刻蚀法在水热条件下制备出了Cu Mn O_2纳米片阵列薄膜。由于同时存在具有催化活性的Cu(Ⅰ)和Mn(Ⅲ),Cu Mn O_2纳米片阵列薄膜对催化H2O_2氧化降解亚甲基蓝(MB)溶液具有优异的效果。进一步放大实验表明,该Cu Mn O_2薄膜具有稳定的催化性能。基于基底生长的薄膜催化剂能够解决粉体催化剂容易团聚、分离回收困难和容易造成二次污染等问题,在染料废水处理方面具有很好的工程应用前景。     

膜电解处理含铜电镀废水研究

以氨水为电解质处理含铜电镀废水的膜电解过程中,通过阳离子交换膜迁移的主要离子包括Cu2、NH4+及H+,废水中Cu2的去除方式包括在电场力和渗析作用下废水中Cu2+通过阳离子交换膜进入阴极室,以及由于NH4+的迁移,在废水中形成Cu(OH)2絮体.采用膜电解技术,在V(氨水)∶V(纯水)分别为3∶5、2∶5、1∶8的情况下,对p(Cu2+)=109 mg/L电镀废水进行膜电解去除废水中Cu2的实验研究.结果表明,在V(氨水):V(纯水)为3∶5时,电解5h,废水中Cu2+去除率为94.71％,ρ(Cu2+)为5.79 mg/L;废水中形成的Cu(OH)2絮体中Cu2的质量浓度约占膜电解过程去除ρ(Cu2+)的40％.     

Synthesis of CuO nanowalnuts and nanoribbons from aqueous solution and their catalytic and electrochemical properties

One dimensional copper hydroxide nanostrands, two dimensional Cu(2)(OH)(3)NO(3) nanoribbons and three dimensional CuO nanowalnuts were synthesized from the same diluted copper nitrate solution with ethanolamine at room temperature and 10 °C, respectively. The Cu(2)(OH)(3)NO(3) nanoribbons were formed by slowly hydrolyzing ethanolamine at low temperature. The CuO nanowalnuts were formed through dehydration of copper hydroxide nanostrands in aqueous solution at room temperature. Although their average size is about 500 nm, the specific surface area of the CuO nanowalnuts can be as large as 61.24 m(2) g(-1), due to their particular morphology with assembling of 8 nm grains. The Cu(2)(OH)(3)NO(3) nanoribbons were converted to CuO porous nanoribbons, keeping the shape. The catalytic performance of the CuO nanowalnuts for CO oxidation is 160 mL h(-1) g(cat)(-1) which is 23 times higher than those of the CuO porous nanoribbons and 40 nm commercial CuO nanoparticles, respectively. The electrochemical properties of the CuO nanowalnuts were also examined in a lithium-ion battery. After 30 cycles, the capacity of the as-prepared CuO nanowalnuts could sustain 67.1% (407 mA h g(-1)) of the second cycle (607 mA h g(-1)) at a rate of 0.1 C.     

Synthesis and H2 uptake of Cu2(OH)3Cl, Cu(OH)2 and CuO nanocrystal aggregate

Monodispersed Cu₂(OH)₃Cl nanoplatelets, Cu(OH)₂ nanowires, CuO nanoparticles and nanoribbons with a spherical morphology were synthesized using hydrothermal and heat-treatment reactions, and their H₂ storage characteristics were examined. The Cu₂(OH)₃Cl nanoplatelets particles formed immediately after mixing the reactant, which subsequently formed larger uniform spherical particles in the submicron range. This procedure highlights a practical strategy for producing spherical Cu(OH)₂ and CuO materials consisting of monodispersed nanocrystals. The spherical aggregates of Cu₂(OH)₃Cl nanoplatelets heat-treated at 473 K could reversibly store up to 2.35 wt.% H₂ at 38 bar and 293 K.     

共沉淀法制备Cu/ZnO催化剂用于1,4-丁二醇合成吡咯

采用共沉淀法制备的Cu/ZnO催化剂成功应用于1,4-丁二醇合成吡咯的反应,利用气质、红外光谱对产物进行定性和定量分析,同时采用XRD、H2-TPR、N2O分解对Cu/ZnO催化剂的成分Cu0和ZnO的作用进行分析。实验研究表明,Cu0是该反应的催化活性中心,ZnO起到了分散和稳定铜颗粒的作用,这种作用是由于在催化剂制备过程中形成了CuZn(OH)2CO3和(CuZn)5(OH)6(CO3)2这两种前体导致的。尽管Cu0是该反应的催化活性中心,Cu/ZnO催化剂的催化活性与Cu0的比表面积不呈线性关系,该反应具有晶面敏感性。在常压、280 ℃、1,4-丁二醇的空速为0.46 h?1、氨醇摩尔比为1.1∶1条件下对催化剂进行评价,Cu/Zn摩尔比为1∶1时1,4-丁二醇的转化率为100%,吡咯有较佳的选择性为58%。     

THPED化学镀铜溶液中Cu(Ⅱ)的存在形式与阴极还原

采用循环迭代法研究了以四羟丙基乙二胺(THPED)为配位剂的化学镀铜溶液中Cu(Ⅱ)的主要存在形式。通过循环伏安法,研究了Cu(Ⅱ)的阴极还原反应。研究表明:THPED(以T表示)与Cu(Ⅱ)形成的配合物主要是CuT(OH)2和CuT2(OH)2,其浓度分别占总Cu(Ⅱ)浓度的56%和42%。CuT(OH)2和CuT2(OH)2分别在电位-0.7V和-1.2V左右(均相对于饱和甘汞电极)发生如下不可逆的电化学还原:CuT(OH)2+2e-→Cu+T+2OH-和CuT2(OH)2+2e-→Cu+2T+2OH-。     

Synthesis and characterisation of self-assembled SiC nanowires and nanoribbons by using sol–gel carbothermal reduction

ABSTRACT

Hexagonal-shaped 3C-SiC nanowires were grafted onto SiC nanoribbons by a sol–gel technique using ferrocene as catalyst. The nanowire diameter (～200?nm) and the nanoribbon width–thickness ratio (20:1) are uniform along their entire length. Their length is about several tens to several hundreds of micrometres. Meanwhile, single SiC nanostructure (nanowire or nanoribbon) was obtained by adjusting temperature field. A novel cooperative growth mechanism of vapour–liquid–solid and vapour–solid was proposed for the self-assembled SiC nanostructure. The self-assembled SiC nanowires and nanoribbons exhibit two strong broad photoluminescence peaks at wavelengths of about 373 and 471?nm, which are significantly shifted to the blue compared with the reported luminescence of SiC nanowires. This study will pave a way for the controllable synthesis of SiC nanowires and nanoribbons, and provide a simple method to connect them together firmly as potential applications for nanodevices in future.     

配位沉淀制备高比表面积氢氧化铜纳米线/纳米棒

以CuSO4?5H2O、氨水和NaOH为原料,采用配位沉淀法制备了不同形貌的Cu(OH)2纳米粉末,考察了NaOH用量、氨水用量和CuSO4初始浓度对颗粒形貌、粒度和比表面积的影响. 结果表明,在CuSO4初始浓度0.1 mol/L、摩尔比NH3:CuSO4=7和NaOH:CuSO4=2~4的条件下,Cu(OH)2由纳米线组装成花簇状,随NaOH用量增加,单头簇状结构减少,双头花簇状结构增多;在CuSO4初始浓度0.1 mol/L、摩尔比NaOH:CuSO4=2和NH3:CuSO4=7的条件下,得到由长径比为20~60的纳米线组成的直径为0.3~1 μm、长1~3 μm的花形簇状Cu(OH)2颗粒,其粒度分布均一,比表面积达83.3 m2/g,表面存在吸附水;在摩尔比NH3:CuSO4=3,NaOH:CuSO4=2的条件下,随CuSO4初始浓度降低,Cu(OH)2纳米线倾向组装成花形簇状结构.     

Amplified spontaneous emission from single CdS nanoribbon with low symmetric cross sections

CdS nanoribbons with various cross sections offer the opportunity to deeply understand the interaction between optical cavity and spontaneous emission. Herein, long tapered nanoribbons with the cross sections gradually changing were synthesized by a simple physical vapour deposition method. Morphology dependent micro-region photoluminescence (PL) spectroscopy is employed to show Purcell effect along different low symmetry cross sections. Spikes on the PL spectra reveal that local density of optical modes increases when the mode match happens between optical cavity and spontaneous emission. Bound exciton complex related amplified spontaneous emission is observed in a single CdS nanoribbon with well-defined elliptical cross sections and optimized width/thickness ratio ～1.45. Polarized Raman and TEM confirmed that the nanoribbon with the elliptical cross section adopts the [0002] growth direction with good quality. The results suggest that the cross section resonant cavity would be of importance for both fundamental and practical application of cavity quantum electrodynamics in CdS nanoribbon.     

Effect of sub-layer thickness on magnetic and giant magnetoresistance properties of Ni-Fe/Cu/Co/Cu multilayered nanowire arrays

Ni–Fe/Cu/Co/Cu multilayered nanowire arrays were electrodeposited into anodic aluminum oxide template by using dual-bath method at room temperature. Scanning electron microscopy and transmission electron micros-copy were used to characterize the morphology and structure of the multilayered nanowire arrays. Vibrating sample magnetometer and physical property measurement system were used to measure their magnetic and giant magnetoresistance (GMR) properties. The effect of sub-layer thickness on the magnetic and GMR proper-ties was investigated. The results indicate that magnetic properties of electrodeposited nanowires are not affect-ed obviously by Cu layer thickness, while magnetic layers (Ni–Fe and Co layers) have significant influence. In addition, GMR ratio presents an oscillatory behavior as Cu layer thickness changes. The magnetic and GMR properties of the multilayered nanowire arrays are optimum at room temperature for the material structure of Ni–Fe (25 nm)/Cu (15 nm)/Co (25 nm)/Cu (15 nm) with 30 deposition cycles.     

Influence of dehydrating agents on the oxidative carbonylation of methanol for dimethyl carbonate synthesis over a Cu/Y-zeolite catalyst

The influence of the dehydration by metal oxides on the synthesis of dimethyl carbonate(DMC) via oxidative carbonylation of methanol was studied. A Cu/Y-zeolite catalyst was prepared by the ion exchange method from CuCl_2·2 H_2O and the commercial NH_4-form of the Y type zeolite. The catalyst was characterized by X-ray fluorescence(XRF), N_2 adsorption(BET method), X-ray diffraction(XRD), and temperature-programmed desorption of ammonia(NH_3-TPD) to evaluate its Cu and Cl content, surface area, structure, and acidity. Reaction tests were carried out using an autoclave(batch reactor) for 18 h at 403 K and 5.5 MPa(2CH_3OH + 1/2O_2+CO?(CH_3O)_2CO + H_2O). The influence of various dehydrating agents(ZnO, MgO, and CaO) was examined with the aim of increasing the methanol conversion(X_(MeOH), MeOH conversion). The MeOH conversion increased upon addition of metal oxides in the order CaO MgO ZnO, with the DMC selectivity(SDMC) following the order MgO CaO ZnO. The catalysts and dehydrating agents were characterized before and after the oxidative carbonylation of methanol by thermogravimetric and differential thermogravimetric(TG/DTG), and XRD to confirm that the dehydration reaction occurred via the metal oxide(MO + H_2O → M(OH)_2). The MeOH conversion increased from 8.7% to 14.6% and DMC selectivity increased from 39.0% to 53.1%, when using the dehydrating agent CaO.