乙二醇中机械化学法制备纳米CuO粉体

以CuSO4·5H2O与NaOH为反应物, 在乙二醇中机械化学法直接合成了纳米CuO粉体.用扫描电镜(SEM)、透射电镜(TEM)和X射线衍射(XRD)对产物进行了表征.结果表明,产物CuO颗粒大小比较均匀,平均粒径30nm左右.对于反应机理,认为是固-固反应中放出的大量的热,使Cu(OH)2直接转化为CuO粒子.该方法具有合成工艺简单、产率高等特点.     

室温固相合成前体法制备纳米CuO粉体

以Cu(NO3)2·3H2O和NH4HCO3为原料,利用室温固相反应首先制备出对H2O2分解具有极高催化活性的纳米级混合碱式铜盐粉体,然后经230℃焙烧2h得纳米CuO粉体,并借助XRD、SEM、FT IR、TEM、TGA和DTA等手段对产物的结构、大小、形貌及相关性质进行了表征。结果表明获得了外貌呈球形、大小均匀、无团聚、平均粒径为28nm的纳米CuO粉体。     

CuO/ZnO复合光催化剂的制备和性能

以十六烷基三甲基溴化铵为生长调节剂用一步水热法合成了纳米CuO/ZnO复合光催化剂。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱仪(XPS)、荧光光谱仪(FL)和紫外-可见光谱仪(UV-Vis)等手段对其表征,在紫外光照射下研究了不同CuO配比的复合光催化剂对目标降解物甲基橙的光催化效果和循环稳定性。结果表明,CuO/ZnO复合光催化剂主要由CuO纳米颗粒和ZnO纳米片组成;引入适量的CuO可调节ZnO的光吸收性能,提高紫外光催化效率;过量(?7%)的CuO抑制ZnO的紫外光催化效率;CuO/ZnO在光催化过程中具有良好的稳定性。     

高分子网络凝胶法制备YAG:Er~(3+)纳米晶粉体及其光谱性质

采用高分子网络凝胶法,在较低温度下制备了YAG:Er~(3+)纳米晶粉体.分别用热重-差热分析(TG-DSC)、X射线衍射(XRD)、扫描电子显微镜(SEM)以及激发和发射光谱对样品进行了表征.结果表明:石榴石晶相的形成温度为880℃,与YAG纳米晶粉体相比,用Er~(3+)代替Y~(3+)后,YAG:Er~(3+)纳米晶粉体还是以石榴石晶相为主,未发生明显变化;YAG:Er3~(3+)纳米晶粉体有丰富的吸收谱线,并且在260nm激发光激发下YAG:Er~(3+)纳米晶粉体可以发射出377nm紫光,可以作为紫光光源的考虑对象.     

不同形貌CuO纳米粒子的制备与性能

采用CuSO4.5H2O、Cu(NO3)2、(CH2)6N4和NaOH为原料,采用沉淀法分别制备纤维状CuO纳米粒子和纺锤状CuO纳米粒子,用透射电镜和X射线衍射仪对产物的大小﹑形貌和组成进行表征;按质量比为9∶1的比例将黑索金分别与纤维状CuO纳米粒子和纺锤状CuO纳米粒子混合,对样品进行热失重测试分析,根据黑索金热分解温度的变化来衡量催化剂的活性。结果表明,采用沉淀法制备CuO纳米粒子时,反应温度、终点pH值对产物形貌有显著影响;不同形貌的CuO纳米粒子对黑索金的分解催化作用效果不同。     

不同溶剂对溶胶-凝胶法制备La2CuO4晶体的影响

以硝酸镧和硝酸铜为起始原料,柠檬酸为络合剂,分别以蒸馏水、乙醇、乙二醇和乙二醇甲醚为溶剂,采用溶胶-凝胶法制备了La2CuO4纳米晶。通过X射线衍射(XRD)、红外光谱(IR)、扫描电子显微镜(SEM)和紫外-可见-近红外光谱(UV-Vis-NIR)等方法对La2CuO4粉体进行了测试和表征;研究了不同溶剂对La2CuO4相组成、官能团、显微结构以及光学性能的影响。结果表明,以蒸馏水、乙醇和乙二醇为溶剂,600℃煅烧保温2h,均能获得单一La2CuO4物相,而以乙二醇甲醚为溶剂时,产物含有杂质相,所得粉体的形貌依次为网片状、蜂窝状、网状和块状。根据UV-Vis-NIR分析,所得La2CuO4的光学带隙分别为1.37、1.30、1.33和1.32eV。     

以阳极氧化铝模板为基底水热法合成纳米氧化铜

本文将阳极氧化铝(AAO)模板与水热法相结合,在150℃的条件下,以AAO模板为衬底制备了CuO纳米片及片状CuO晶体网络结构。反应过程中不需要添加任何辅助试剂,硫酸铜氨分解成氧化铜,并在阳极氧化铝模板上生成氧化铜纳米片及氧化铜纳米片网状结构。用SEM、XRD对制备的纳米CuO进行了形貌表征和结构分析,初步探讨了CuO纳米片网状结构的形成机理。     

TiN/聚吡咯纳米复合材料的制备及表征

采用氨解法制备了纳米氮化钛(TiN)粉体,对纳米TiN粉体进行表面改性,使其均匀分散到吡咯单体中.采用原位聚合法制备了TiN/聚吡咯(PPy)纳米复合材料.对合成的复合材料用X射线衍射(XRD)、透射电镜(TEM)、傅立叶变换红外光谱(FT-IR)、四探针测试仪等方法进行了表征与检测.结果表明:PPy成功地包覆在TiN纳米颗粒表面,形成了纳米TiN/PPy复合材料.复合材料具有优良的电性能.     

针状纳米CuO的制备及其催化性能研究

研究了水热反应条件对纳米CuO结构和形貌的影响.采用XRD、FTIR、TEM等测试手段对产物进行了表征,并用热分析法考察了不同粒径纳米CuO对高氯酸铵(AP)分解的催化作用.结果表明通过调节反应物浓度可以控制针状CuO直径在8～15nm,通过控制反应温度和反应时间可以得到CuO和Cu2O两种产物.不同粒径的纳米CuO均能强烈催化AP的分解,其中8nm的针状纳米CuO催化活性最强,可使AP高温分解峰降低93.64℃,分解放热量由590.12J/g增至1390J/g.     

液体羧基丁腈橡胶对纳米Si3N4粉体表面处理研究

用液体羧基丁腈橡胶作表面处理剂处理纳米氮化硅(Si3N4)粉体.结果表明:液体羧基丁腈橡胶包覆在纳米Si3N4粉体的表面,并与其发生了化学作用,有效地阻止了纳米Si3N4粉体的团聚;处理过的Si3N4粉体粒径明显减小,在有机溶剂中的分散性良好;亲水性减小,亲油性增加,表面自由能明显降低,处理后的纳米Si3N4粉体更容易在聚合物中分散.     

挤压角度对AgCuO复合材料组织演变的影响

研究了挤压角度对AgCuO复合材料组织变化的影响。通过试验结果与有限元模拟结果进行对比,进一步证实有限元模拟的真实性以及试验结果的准确性。结果表明:当两个立方CuO位置较近且周围没有单斜CuO时,立方CuO都从多边形变为直线形纤维;而当单斜与立方CuO位置较近时,立方CuO由多边形变为弯曲的纤维状,单斜CuO也发生了部分变形。此外,随着模具角度的增大,试样表面附近的CuO颗粒分散性逐渐增强,立方CuO纤维不断变细变长,而且立方CuO颗粒纤维化现象沿径向向内逐渐减少。试样所受应力不断增加,且最大应力出现在定径带入口附近;变形区作用范围不断减小,但应力却不断增加。     

A novel solid-stabilized emulsion approach to CuO nanostructured microspheres

Nanostructured CuO microspheres were prepared by a novel solid-stabilized emulsion for the first time. SEM, TEM, XRD, size analysis and BET measurement were used to characterize the CuO microspheres. The average diameter of the CuO microspheres was 2.8 μm. The surfaces of the CuO microspheres were made of pin-like nanostructures with a pin diameter of 95 nm and a pin length of at least 600 nm. The XRD analysis indicated that the CuO nanostructured microspheres were of monoclinic lattice. The specific surface area of the CuO nanostructured microspheres was about 56.8 m²/g. A mechanism for the formation of the CuO microspheres with nanostructured surfaces was proposed.     

Spherical CuO synthesized by a simple hydrothermal reaction: Concentration-dependent size and its electrocatalytic application

Spherical CuO was synthesized by a simple hydrothermal reaction with the yield as high as ∼90%. The size of the CuO spheres can be facilely and selectively controlled to range from several hundred nanometers to a few micrometers simply by adjusting the concentration of the reactants. The CuO spheres consist of many small and uniform nanoneedles with tips about tens of nanometers in diameter. Interestingly, it was found that the initial concentration of reactants plays an important role in the formation of spherical CuO with different size. A growth mechanism of spherical CuO was also proposed based on the observed results. The cyclic voltammogrametry reveals that CuO nanospheres exhibit a remarkable electrocatalytic activity for the oxidation/reduction of H₂O₂. This study provides a promising route for the facile and cost-effective synthesis of inorganic nano- and micromaterials, and the synthesized CuO shows great promise in electrochemical applications.     

铈掺杂氧化铜纳米颗粒的制备及其抗菌性能研究

采用水热法制备了铈离子掺杂的氧化铜纳米颗粒(Ce-CuO NPs)。FESEM图像显示掺杂氧化铜为球形和近球形颗粒;XRD图谱表明,当掺杂量低于10%时,图谱中只出现了单斜结构的CuO衍射峰,当掺杂量增加至15%时,形成了CeO2独立相;ICP分析表明,铈元素的掺杂对CuO NPs中铜离子的释放具有促进作用。铈掺杂氧化铜纳米颗粒的抗菌测试结果显示,其对革兰氏阳性菌金黄色葡萄球菌(S.aureus)的抗菌能力,较革兰氏阴性菌大肠杆菌(E.coli)更为显著;其中,5% Ce-CuO NPs在0.05 mg/mL的低浓度下表现出最佳的抗菌效果。Cu^2+与细菌细胞表面的结合在抑制细菌生长的过程中起到重要作用。     

Scalable microwave-assisted continuous flow synthesis of CuO nanoparticles and their thermal conductivity applications as nanofluids

We have demonstrated the novel and scalable synthesis of CuO nanoparticles by an integration of microwave and flow synthesis. The shape and size of CuO nanoparticles were tuned by changing the concentration of copper precursor. The production rate of CuO nanoparticles was found to be 5?g/h with 70% conversion of copper acetate into the CuO nanoparticles. The thermal conductivity of CuO nanofluid prepared in ethylene glycol showed linear enhancement with increase in the volume content of CuO nanoparticles produced in batch and flow reactors.     

Effect of CuO Addition on the Sintering Behavior and Electrical Conductivity of 3Y-TZP

Yttria stabilized tetragonal zirconia polycrystals （3Y-TZP） doped with CuO was prepared, to get two compositions, 0.3 and 1 mole fraction CuO, respectively. The dilatometric study of the samples showed sintering to be improved for the samples doped with 0.3 mole fraction CuO, and to be deteriorated for the samples doped with 1 mole fraction CuO. The 1 mole fraction CuO doped 3Y-TZP showed higher tetragonal/monoclinic phase transformation which was accompanied by grain growth. The electrical conductivity decreased with the addition of CuO.     

Understanding the Antibacterial Mechanism of CuO Nanoparticles: Revealing the Route of Induced Oxidative Stress

To date, there is still a lack of definite knowledge regarding the interaction of CuO nanoparticles with bacteria and the possible permeation of the nanoparticles into bacterial cells. This study was aimed at shedding light on the size‐dependent (from the microscale down to the small nanoscale) antibacterial activity of CuO. The potent antibacterial activity of CuO nanoparticles was found to be due to ROS‐generation by the nanoparticles attached to the bacterial cells, which in turn provoked an enhancement of the intracellular oxidative stress. This paradigm was confirmed by several assays such as lipid peroxidation and reporter strains of oxidative stress. Furthermore, electron microscopy indicated that the small nanoparticles of CuO penetrated the cells. Collectively, the results reported herein may reconcile conflicting concepts in the literature concerning the antibacterial mechanism of CuO nanoparticles, as well as highlight the potential for developing sustainable CuO nanoparticles‐based devices for inhibiting bacterial infections.     

Preferred orientation and interdiffusion in zinc oxide/copper oxide multilayered films

ZnO/CuO and ZnO/ZnO CuO/CuO multilayered films were deposited on Pyrex substrates at <100° C by ion-beam sputtering. The preferred orientation and interdiffusion of these films were examined for films with varying layer repeat lengths (pari thickness). X-ray diffraction analysis showed a preferred ZnO (002) orientation parallel to the surface in annealed ZnO layers of ≈1 to ≈3 nm thickness; no peak was observed for films with a layer repeat length smaller than 1.1 nm. The degree of preferred orientation reduced with increasing layer thickness in ZnO/CuO films and with increasing ZnO CuO thickness in ZnO/ZnO CuO/CuO films. The decay rate of the low-angle X-ray intensity showed that interdiffusivity is largely dependent on the layer repeat length. A smaller layer repeat length gave a larger value of interdiffusivity.     

Syntheses and gas-sensing properties of CuO nanostructures by using [Cu(pbbt)Cl2]2·CH3OH as a precursor

The rod-like and dandelion-like CuO nanomaterials have been prepared by the decomposition of a copper complex [Cu(pbbt)Cl₂]₂·CH₃OH (pbbt = 1,1′-(1,3-propylene)-bis-1H-benzotriazole) in the presence of suitable surfactants and alkalies under hydrothermal conditions. The CuO nanorods are about 50 nm in diameter and up to 500-700 nm in length; the average diameter of the dandelion-like CuO microspheres is of 2 μm. A formation mechanism for the CuO nanomaterial was proposed. The gas-sensing properties of as-prepared CuO nanomaterial were studied. The sensitivity of the as-prepared CuO nanorods was better than that of dandelion-like CuO particles, and the CuO nanorods displayed special sensitivity to alcohol.     

Synthesis and characterization of CuO nanoparticles from liquid ammonia

A new type of CuO nanoparticles were synthesized in liquid ammonia in the presence of sodium metal. First, Cu nanoparticles were obtained by reducing copper nitrate with the alkali metal in liquid ammonia, then, CuO nanoparticles were formed in the ambient conditions. The morphology and structure of as-prepared CuO nanoparticles were characterized by TEM and XRD, and the reason of aggregation of CuO nanoparticles was supposed.