以生物蛋白为模板控制合成MnO_2纳米颗粒

利用生物模拟矿化技术原位合成金属氧化物纳米颗粒。利用超分子蛋白纳米空腔结构作为反应模板矿化组装纳米材料,马脾铁蛋白作为限制性反应器控制金属离子水解、氧化还原等反应组装成单分散的纳米粒子。在碱性条件下脱铁铁蛋白限制性合成Mn氧化物纳米颗粒,通过透射电子显微镜(TEM)、EDX元素分析对产品的结构和组成进行表征,产品为球形颗粒状,直径分布在3～8nm范围。此外,采用紫外、可见吸收光谱分析对蛋白组装过程做了实验研究并对纳米材料形成机理进行了讨论。     

CoO/CdS纳米复合材料的制备及其光催化降解亚甲基蓝的研究

采用物理气相沉积法制备CoO/CdS纳米复合材料,通过扫描电子显微镜(SEM)、X射线衍射仪(XRD)、X射线能谱仪(E DS)和紫外-可见分光光度计(UV-Vis)对其形貌、结构和光吸收性质进行表征,并以亚甲基蓝溶液的光催化降解为探针反应,在可见光下考察CoO/CdS纳米复合材料的光催化性能.结果表明,CoO/CdS纳米复合材料的光催化活性显著高于CdS纳米颗粒,100 min后亚甲基蓝降解率达到92.4％.     

溶剂热法合成纳米级CoO粉体及其生长习性

以四水醋酸钴和无水乙醇为原料,采用溶剂热法在150℃制备了纳米晶体CoO. 利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等手段对产物进行了分析和表征. 结果表明,产物CoO晶体为面心立方结构,晶粒尺寸约为50 nm,大小均匀,分散性好. 研究了不同合成条件对CoO晶粒尺寸的影响,并分析了CoO的结晶习性,在低过饱和度条件下,CoO晶体因{111}晶面生长速度最慢而显露,因此它的形貌为八面体     

CuO(CoO,MnO)/SiO2纳米复合气凝胶催化剂载体的溶胶-凝胶法制备及成胶机理

采用正硅酸乙酯(tetraethyl orthosilicate,TEOS)和Cu,Co,Mn的醋酸盐溶液,通过溶胶-凝胶法、常压干燥制备了过渡金属氧化物含量高达75%(质量分数)的CuO(CoO,MnO)/siO2纳米复合气凝胶,对其成胶机理进行了分析.结果表明:制得的CuO(CoO,MnO)/SiO2纳米复合气凝胶具有SiO2气凝胶的纳米孔隙三维网络结构和高比表面积;当过渡金属醋酸盐与TEOS的比例不同时,Cu,Co和Mn能够与氧在网络结构中形成不同程度的-O-M-O一桥键连接;通过气凝胶的多孔网络分隔作用,可使更多过渡金属氧化物CuO,CoO和Mno的超细粒子均匀分散于CuO(CoO,MaO)/SiO2复合气凝胶或SiO2气凝胶骨架中.这种结构既有利于提高催化剂负载量,又能充分利用CuO,CoO和MaO的助催化作用,因此CuO(CoO,MnO)/SiO2纳米复合气凝胶可作为催化剂载体用于催化合成碳酸二苯酯及其它催化领域.     

CuO（CoO，MnO）／SiO2纳米复合气凝胶的溶胶-凝胶法制备、成胶机理及表征

采用正硅酸乙酯(tetraethyl orthosilicate.TEOS)和Cu、Co、Mn的醋酸盐溶液.通过溶胶-凝胶法、常压干燥制备了过渡金属氧化物含量高达75wt%的CuO(coO,MnO)/SiO2纳米复合气凝胶.采用透射电镜(TEM),傅里叶变换红外分析(FTIR)、电子散射能谱分析(EDS)和化学分析等对其微观结构、组成及成胶机理进行了探讨.结果表明:CuO(coO,MnO)/SiO2纳米复合气凝胶的颗粒约在5～10nm,并具有SiO2气凝胶的纳米孔隙三维网络结构和高比表面积;根据过渡金属醋酸盐与TEOS比例的不同,Cu、Co和Mn能够与氧在网络结构中形成不同程度的-0-M-o-桥键连接;通过气凝胶的多孔网络分隔作用,可使更多金属氧化物CuO、CoO和Mno的纳米粒子均匀分散于CuO(coO,MnO)/SiO2复合气凝胶或SiO,气凝胶骨架中.这种结构既有利于提高催化剂负载量,又可充分利用CuO,CoO和MnO的助催化作用.     

含氟两亲纳米颗粒的制备与表征

采用Stber方法合成SiO_2纳米颗粒,通过Pickering乳液模板法制备含氟两亲纳米颗粒(SiO_2/APTES/HFBA),并对其表面活性进行评价。利用粒径分析仪、傅里叶变换红外光谱仪(FT-IR)和表面张力仪对含氟两亲纳米颗粒的粒径分布、化学组成和界面活性进行分析表征。结果表明,实验合成的SiO_2纳米颗粒粒径分布狭窄,平均粒径为192 nm。制备的含氟两亲纳米颗粒(SiO_2/APTES/HFBA)在质量分数达到0. 6%时,其在界面上的吸附达到饱和,此时,表面张力为35. 2 m N/m,具有较优异的界面活性。     

单分散性Fe_3O_4/CoO/SiO_2复合纳米粒子的制备与表征

采用溶剂热法,在160℃下,以聚乙烯吡咯烷酮(PVP)为表面活性剂,制备Fe3O4/CoO复合纳米粒子;然后采用St觟ber法,在35℃下,以氨水催化正硅酸乙酯(TEOS),制备Fe3O4/CoO/SiO2复合纳米粒子。考察反应物配比、氨水浓度、醇水比对Fe3O4/CoO/SiO2复合粒子磁学性能的影响。对复合纳米粒子采用X射线衍射(XRD)、透射电子显微镜(TEM)、交流梯度磁强计(VSM)、差热分析(DTA)等手段进行表征分析。结果表明:Fe3O4/CoO/SiO2复合纳米粒子晶形生长良好,粒径在20nm左右。利用CoO进行表面修饰后,提高了纳米Fe3O4粒子的饱和磁化强度,通过包覆SiO2进行表面改性后,提高了纳米Fe3O4粒子的分散性和稳定性。实验确定了Fe3O4/CoO复合粒子与TEOS的摩尔比1∶2、TEOS与氨水的摩尔比1∶3、无水乙醇与蒸馏水的体积比2∶1为最佳反应物配比。     

氟化SiO2纳米颗粒双疏涂层的制备及性能研究

采用氟化硅烷偶联剂对合成的单分散SiO2纳米颗粒进行表面接枝改性,并通过旋涂法将制备的氟化SiO2颗粒沉积在硅晶基板上.采用粒径分析仪、傅里叶变换红外光谱仪(FTIR)、热重分析仪(TG-DTA)、扫描电镜(SEM)和接触角测量仪对氟化SiO2纳米颗粒涂层的表面形貌、化学组成、接枝密度和润湿性能进行分析表征.结果表明:氟化硅烷偶联剂在SiO2纳米颗粒表面的接枝密度为5.94 nm-2;制备的氟化SiO2纳米颗粒薄膜具备微纳米双重复合网络结构,增加了涂层表面的粗糙程度;氟化SiO2纳米颗粒涂层展现出超疏水和强疏油性能,水和柴油在氟化SiO2纳米颗粒薄膜上的接触角分别为158.4°和125.7°.     

化纤应用及处理

TQ340.6520133243用于制备生物活性聚酯的甲壳质和载银甲壳质纳米颗粒的合成及其特性Ali S.Wazed…;Carbohydrate Polymers,2011,83(2),p.438(英)文章聚焦于甲壳质纳米颗粒(CSN)的合成,通过与三聚磷酸钠进行离子型凝胶反应,随后加载银离子,生产载银甲壳质纳米颗粒(Ag-CSN)。载银的目的是在纳米颗粒成形过程中强化甲壳质的抗菌性,这样,当其被应用于聚酯织物时可提高杀菌性。CSN和Ag-CSN的平均颗粒尺寸分别是115nm和165nm。     

腐生葡萄球菌合成纳米钯异位还原废水中Cr(Ⅵ)

利用腐生葡萄球菌(Staphylococcus saprophyticus.JJ-1)合成金属钯纳米颗粒,对其进行了表征;并利用"细菌/钯纳米颗粒"复合体系还原Cr(Ⅵ).结果表明,与其它检测的碳源相比,以甲酸钠为碳源还原钯盐,合成钯纳米颗粒的速度最快.在细胞干质量浓度为0.8g/L时,所合成的钯纳米颗粒催化还原Cr(...     

Anchoring CoP nanoparticles on the octahedral CoO by self-phosphating for enhanced photocatalytic overall water splitting activity under visible light

Designing an effective and stable composite photocatalyst is of significance for the further realization of practical applications. In this study, a series of CoP/CoO composites are successfully prepared by a straight one-step phosphating method. The reasonable design and controllable preparation of CoP/CoO composite make it exhibit improved photocatalytic performance for overall water splitting and excellent stability under visible light irradiation in comparison with pure CoO, which is derived from the CoP nanoparticles well dispersed on the (111) facets of CoO octahedrons, intimate interface between them and efficiently accelerated of photo-induced electrons from CoO to CoP. This study presents a simple method to design highly-effective composite photocatalysts for overall water splitting to meet the energy demand.     

Cobalt oxide nanoparticles on mesoporous MCM-41 and Al-MCM-41 by supercritical CO2 deposition

CoO and Co₃O₄ nanoparticles were uniformly dispersed inside mesoporous MCM-41 and Al-MCM-41 supports using supercritical CO₂ reactive deposition. This method represents a one-pot reproducible procedure that allows the dissolution of the organocobalt precursor and supports impregnation in supercritical CO₂ at 70 °C and 110 bar, followed by the precursor thermal decomposition into cobalt species at 200 °C and 160 bar. By the relative concentration of the cobalt precursor [cobalt (II) bis (η⁵-ciclopentadienil)], the load of cobalt nanoparticles was controlled and then determined by Inductively Coupled Plasma (ICP-OES). The synthesis of CoO and Co₃O₄ species inside the MCM-41 and Al-MCM-41 substrates was confirmed by X-ray Photoelectron (XPS) and Laser Raman Spectroscopies (LRS). By N₂ adsorption and Small Angle X-ray Scattering (SAXS), it was determined that the hexagonal arrangement as well as the surface area and pore size of the substrates changed after the addition of cobalt. By means of X-ray mapping from SEM images, a homogeneous distribution of cobalt nanoparticles was observed inside the mesopores when the cobalt loading was 1 wt.%. In addition, spherical cobalt nanoparticles of average diameter close to 20 nm were detected on the outer surface of MCM-41 and Al-MCM-41 supports when the cobalt content was higher. On the other hand, by Transmission Electron Microscopy (TEM), it was possible to measure the interplanar distance of the crystalline plane of the outer nanoparticles, which was later compared with the theoretical distance values which allowed identifying the CoO and Co₃O₄ phases.     

Selective Allylic oxidation of Cyclohexene by a Magnetically Recoverable Cobalt Oxide Catalyst

Abstract  

In this work, we prepared a new magnetically recoverable CoO catalyst through the deposition of the catalytic active metal nanoparticles of 2–3 nm on silica-coated magnetite nanoparticles to facilitate the solid separation from liquid media. The catalyst was fully characterized and presented interesting properties in the oxidation of cyclohexene, as for example, selectivity to the allylic oxidation product. It was also observed that CoO is the most active species when compared to Co²⁺, Co₃O₄ and Fe₃O₄ in the catalytic conditions studied.     

大孔SiO_2载体制备La_(0.8)Sr_(0.2)CoO_3及其对NO+CO的催化性能

以具有高比表面积的大孔SiO_2为载体,采用浸渍法,通过控制浸渍液浓度的不同原位制备不同负载率的稀土钙钛矿型复合氧化物La_(0.8)Sr_(0.2)CoO_3/SiO_2样品。利用X射线衍射、比表面积、扫描电镜和X射线光电子能谱等分析方法对样品进行表征,结果表明,载体表面均匀负载La_(0.8)Sr_(0.2)CoO_3,且随着负载率增加,样品比表面积下降。考察不同负载率的La_(0.8)Sr_(0.2)CoO_3/SiO_2样品对NO+CO的催化活性,结果表明,与比表面积和结晶度相比,负载率在该催化实验体系中是影响最大的因素,综合催化效果最好的样品负载La_(0.8)Sr_(0.2)CoO_3质量分数为50.47%。     

CoO AS ADDITIVE IN POSITIVE ELECTRODE OF NICKEL-METAL HYDRIDE BATTERY

A series of positive electrodes for Ni/MH battery were fabricated by addition of CoO.The morphology and microstructure of the electrodes were examined by SEM and EDS, and electrochemical behavior was investigated in three-compartment appliances at room temperature.The electrochemical performance of the positive electrodes with CoO was improved. Under the same charge-discharge cycle, the electrodes with CoO showed higher specific capacity, lower charge mean voltage and higher discharge mean voltage. But further increasing the content of CoO in the electrodes contributed negative effect on the overall performance. Addition of 8% (mass) CoO was suggested to be a suitable content for the positive electrode.     

Glycerol Hydrogenolysis over Co Catalysts Derived from a Layered Double Hydroxide Precursor

Abstract  

Co catalysts, obtained from a layered double Co–Zn–Al hydroxide, are highly active and stable towards the hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO) in aqueous media. The Co-673 catalyst, containing a CoO species, provided a glycerol conversion of 67.7% and a 1,2-PDO selectivity of 50.5%. The Co-873 catalyst comprising 16 nm Co nanoparticles gave a glycerol conversion of 70.6% and a 1,2-PDO selectivity of 57.8%. It was revealed that the CoO species in the Co-673 catalyst was readily converted to 50 nm Co particles under the glycerol hydrogenolysis conditions. The Co catalysts maintained a stable size and phase in recycling tests.     

The preparation and characteristics of cobalt blue colored mica titania pearlescent pigment by microemulsions

Blue pearlescent pigment was obtained by coating microemulsion-synthesized CoAl₂O₄ nanoparticles onto mica titania. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) showed that the spherical CoAl₂O₄ spinel was around 20 nm and dispersion of the nanoparticles on the coated surface was uniform. EDS revealed that the coating rate and coating efficiency of Co was about 3.12% and 97%, respectively. The study results indicate that the optimum technology parameters were 1:1 CoO:Al₂O₃ molar ratio, and the coating ratio of CoAl₂O₄ was 3.7–4.6% by weight.     

Synthesis of CoO/Ni Composite Powders for Molten Carbonate Fuel Cells

CoO/Ni composite particles were prepared by the advanced mechanical-coating method called Mechanofusion™. These composite particles were composed of nickel particles uniformly covered with fine CoO particles. A new cathode structure for molten carbonate fuel cells (MCFCs), where the NiO core was coated with an outer layer of lithiated cobalt and nickel solid-solution oxide (Li(Co,Ni) oxide), was formed by oxidation and lithiation using these CoO/Ni composite particles. The solubility of nickel in this Li(Co,Ni) oxide layer into carbonate melt decreased to two-thirds of that of NiO when used as a cathode for MCFCs.