氧化铜纳米片组装的球形花状结构的制备、表征及其形成机制

在H_2O和乙醇形成的二元体系中,以CuCl_2·2H_2O为铜源,无水NaAc为沉淀剂,聚乙二醇(PEG)为形貌控制剂,采用一步水热法制备了氧化铜纳米材料。采用X射线衍射(XRD),扫描电子显微镜(SEM)和透射电子显微镜(TEM)等多种手段对产物进行结构表征。结果表明,所得产物具有单斜结构的氧化铜纳米片构建的球形花结构。研究了其生长过程,提出了相关的化学反应和可能的形成机制。     

微米聚苯胺/Fe_3O_4空心球的制备及吸波性能

采用界面聚合和Pickering乳液聚合相结合的方法,以甲苯为软模板,磁性Fe3O4纳米颗粒为稳定剂,十二烷基苯磺酸钠(SDBS)为乳化剂,过硫酸铵(APS)为氧化剂,盐酸(HCl)为掺杂剂,制备了掺杂态聚苯胺/Fe3O4(D-PANI/Fe3O4)空心球.作为比较,在不掺杂盐酸的条件下,制备了本征态聚苯胺/Fe3O4(PANI/Fe3O4)空心球.用透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线衍射(XRD)仪、傅里叶变换红外光谱(FTIR)仪、热重分析(TG)仪、振动样品磁强(VSM)计及恒压四探针测试仪对复合材料的形貌、结构、组成和电磁性能进行了表征.结果表明,D-PANI/Fe3O4空心球的直径约为2.8μm,电导率和饱和磁化强度(Ms)分别为2.75×10-2S/cm和54.26 A·m2/kg.用矢量网络分析(VNA)仪对D-PANI/Fe3O4空心球和PANI/Fe3O4空心球吸波性能进行分析,结果表明,D-PANI/Fe3O4空心球在12.64 GHz处的最小反射率为-43.3 d B,对应的匹配厚度为2 mm,其吸波性能明显优于PANI/Fe3O4空心球.     

不同表面形貌Cu2O空心球的制备及光催化性能

采用一步溶剂热法,以Cu(NO_3)_2·3H_2O为铜源,乙二醇(EG)为还原剂,聚乙烯吡咯烷酮(PVP)为表面活性剂,高温条件下制备形貌可控的Cu_2O空心球纳米材料。研究Cu(NO_3)_2·3H_2O与PVP的质量比值(w_(Cu(NO_3)_2·3H_2O)/w_(PVP))对Cu2O结构、形貌、比表面积以及光吸收特性的影响,并结合光催化机理讨论其对Cu_2O光催化性能的影响。此外,通过改变反应时间来研究Cu_2O的生长过程。结果表明,w_(Cu(NO_3)_2·3H_2O)/w_(PVP)=45时,得到的形貌为空心球表面覆盖纳米刺的Cu_2O纳米材料光催化性能最佳,在可见光辐照10 min的条件下,对甲基橙的降解率达94.3%。     

Co3O4空心球的简易合成及其电化学性能

通过简易的水热法"一锅"制备了Co3O4空心球。借助X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和傅里叶变换红外光谱法(FTIR)等对Co3O4的结构和形貌进行了表征。结果表明,产物由Co3O4纳米粒子构成,并形成明显的空心多孔结构。循环伏安法(CV)测试表明,所制得的Co3O4空心球呈现良好的电化学性能。本文同时对Co3O4空心球结构的形成过程和可能的机理进行了分析和讨论。     

孔状Co_3O_4纳米片和纳米棒的选择性合成和表征(英文)

利用两步实验选择性合成孔状Co3O4纳米片和纳米棒:首先,以Co(NO3)2·6H2O,NaOH和不同量的NH4F为原料在120℃水热6h的条件下合成了Co(OH)2-Co3O4纳米片(S1)和Co(OH)F-Co3O4纳米棒(S2);然后将所得纳米片和纳米棒在400℃时加热2h即得到多孔的Co3O4纳米片和纳米棒。所得产物用X射线衍射(XRD)、场发射扫描电子显微镜(FE-SEM)和透射电子显微镜(TEM)进行了表征。此外电化学测试表明Co3O4纳米棒的电容量比Co3O4纳米片的更大。     

S/Cd物质的量比对微波水热制备CdS微晶的形貌影响及光学性能研究

采用微波水热法,以CdCl2·H2O和Na2S2O3·5H2O为镉源和硫源,在不同的S/Cd物质的量比条件下合成了CdS微晶。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、场发射扫描电子显微镜(FE-SEM)、EDS、透射电子显微镜(TEM)等对样品的物相、形貌和元素组分进行了分析。结果表明:随着S/Cd物质的量比的增大,产物CdS的形貌发生规律性变化,由四面体结构逐渐转变为准球形结构;准球形结构具有分级结构,是由更小的纳米晶组装而成;光致发光性质研究结果表明,所得的CdS微晶具有较好的蓝光发射性能。     

胶质碳球为模板制备NiO空心球

以胶质碳球为模板、六亚甲基四胺为沉淀剂,在乙醇中溶剂热反应,再经500℃煅烧6 h制备了NiO空心球。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱(FTIR)和低温氮吸附-脱附,对NiO的结构和形貌进行了表征。结果表明溶剂热反应时间是制备完整NiO空心球的关键因素,溶剂热反应12 h,再经空气中煅烧,可制得形貌均一的NiO空心球。所得产物是由NiO纳米粒子组装而成的具有多孔结构的空心球。同时,本文对NiO空心球结构的形成过程和可能机理进行了分析和讨论。     

硅藻土原位负载网状纳米结构硅酸镁及其对Cr(Ⅵ)吸附性能

采用MgCl_2·6H_2O作为镁源,NH_3·H_2O作为沉淀剂,十六烷基三甲基溴化铵(CTAB)作为模板剂,以水热法在硅藻土表面原位生长纳米花状Mg(OH)_2,随反应时间增加,转变成单斜晶系网状结构Mg_3Si_4O_(10)(OH)_2纳米花。采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、氮气吸附-脱附测试、傅里叶红外光谱(FT-IR)、X射线光电子能谱(XPS)等测试手段对样品进行了表征,结果显示:反应时间为0.5～2.0 h时硅藻土表面以生长Mg(OH)_2为主,样品的比表面积为180 m~2·g~(-1);反应时间至3h时,硅藻土表面Mg(OH)_2转化成网状结构Mg_3Si_4O_(10)(OH)_2,样品比表面积增大到350 m~2·g~(-1),此复合结构对Cr(Ⅵ)最大吸附量可达570 mg·g~(-1)。     

NiFe2O4磁性纳米材料的溶剂热法一步合成

以Fe(NO_3)_3·9H_2O和Ni(NO_3)_2·6H_2O为原料,在未添加任何碱性沉淀剂和高温晶化处理的条件下,通过对实验条件(包括溶剂、溶剂热温度和时间)的优化,利用溶剂热法一步制备了具有良好结晶性和超顺磁性的NiFe_2O_4磁性纳米材料。结果表明:用H_2O和EtOH-H_2O做溶剂都不利于NiFe_2O_4的生成;用EtOH做溶剂,为了获得纯度较高的NiFe_2O_4磁性纳米材料,要保证适当的溶剂热温度和时间;所得材料的磁性能与材料中磁性组分NiFe_2O_4的含量和其结晶程度有关。该制备方法最突出的优点是简单、快速、成本低、从源头消除了污染,且所得的材料磁性能优良。     

二苯羧酸类稀土配合物对藤黄微球菌抑制作用的微量热研究

合成了4例二苯羧酸类稀土配合物:[Re_2(oba)_3(H_2O)_5]·H_2O[Re=La(1)、Ce(2)、Sm(3)、Er(4)](oba=4,4'-二羧基二苯基醚),利用元素分析、红外光谱和粉末X射线衍射等技术手段对其结构及组成进行了表征,热重分析表明,4例配合物具有良好的热稳定性。采用微量热法,实时跟踪监测4种目标配合物对藤黄微球菌的抑制作用,得到了热谱曲线。依据热动力学模型对热谱曲线进行解析,计算了生长和抑制过程的热动力学函数,在不同浓度配合物存在时,获得了细菌生长速率常数(k)、最大产热功率(P_(max))、传代时间(t_G)以及抑制率(I)等参数。结果表明,4种配合物对藤黄微球菌均具有抑制作用,抑菌效果依次为:[Er_2(oba)_3(H_2O)_5]·H_2O(4)[Sm_2(oba)_3(H_2O)_5]·H_2O(3)[Ce_2(oba)_3(H_2O)_5]·H_2O(2)[La_2(oba)_3(H_2O)_5]·H_2O(1)。     

中空分级结构Fe3O4@C/rGO复合材料的合成及其储锂性能

以氧化石墨烯(GO)为基底,Fe(NO_3)_3·9H_2O、异丙醇、甘油为原料,通过溶剂热法和后续热处理过程2步合成了Fe_3O_4@C/rGO复合材料,实现了碳包覆的Fe_3O_4纳米粒子自组装形成的分级结构空心球在氧化石墨烯片上的原位生长。采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和恒流充放电等手段分析了材料的物理化学性能与储锂性能。结果表明,该复合材料在5.0 A·g~(-1)的电流密度下,仍有437.7 mAh·g~(-1)的可逆容量,在1.0 A·g~(-1)下循环200圈后还有587.3 mAh·g~(-1)的放电比容量。这主要归因于还原态氧化石墨烯(rGO)对碳包覆Fe_3O_4分级空心球整体结构稳定性和导电性的提高。     

Hydrothermal synthesis and photocatalytic property of porous CuO hollow microspheres via PS latex as templates

Porous copper oxide (CuO) hollow microspheres have been fabricated through a simple hydrothermal method using PS latex as templates. The as-obtained samples were characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD) and Fourier transform infrared spectroscopy (FTIR). The influences of the mole ratio of Ethylenediamine (C₂H₈N₂) and copper acetate (Cu(Ac)₂·H₂O), hydrothermal temperature and time on the size and morphologies of the final products have been investigated. The possible formation mechanism of porous CuO hollow microspheres has been proposed and the specific surface area of the hollow microspheres with 81.71 m²/g is measured by BET method. The band gap value calculated from a UV–vis absorption spectrum of porous CuO hollow microspheres is 2.71 eV. The as-synthesized product exhibits high photocatalytic activity during the photodegradation of an organic dyestuff, rhodamine B (RhB), under UV-light illumination.     

片状Co9S8/ZnS/C复合材料的制备及电催化产氧性能

以六水合硝酸钴[Co(NO_3)_2·6H_2O]为钴源、六水合硝酸锌[Zn(NO_3)_2·6H_2O]为锌源、2,2′-硫代二乙酸(C4H6O4S)为硫源,采用溶剂热法制备出了片状的Co_9S_8/ZnS/C复合材料。采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和N_2吸附/脱附测试等手段对于片状Co_9S_8/ZnS/C复合材料结构和形貌等进行表征,同时对片状Co_9S_8/ZnS/C复合材料进行了电催化产氧性能测试。结果表明:片状Co_9S_8/ZnS/C复合材料的起始过电位为390 mV,塔菲尔斜率为144 mV·dec~(-1),具有高的电催化产氧性能。     

O/W/O double emulsion-assisted synthesis and catalytic properties of CeO2 hollow microspheres

CeO₂ hollow microspheres have been fabricated through a simple thermal decomposition of precursor approach. The precursor with an average size of 10 μm was prepared in a reverse microemulsions containing Ce(NO₃)₃·6H₂O and CO(NH₂)₂ at 160 °C. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscope (TEM), selected area electron diffraction (SAED) and scanning electron microscopy (SEM). The possible formation mechanism of hollow spheres was discussed. In addition, the CeO₂ hollow microspheres modified glassy carbon electrode exhibit excellent sensing performance towards methyl orange, which provide a new application of CeO₂ hollow spheres. The catalytic activity of CeO₂ hollow spheres on the thermal decomposition of ammonium perchlorate (AP) also was investigated by TGA. The catalytic performance of CeO₂ hollow spheres is superior to that of commercial CeO₂ powder.     

Influence of Microwave Synthesis Parameters on the Size and Morphology of the Resulting MgAl2O4 Nanoparticles

In the present study, Nano-sized magnesium aluminate powders were successfully synthesized via microwave process based on the reaction between Mg (NO₃)₂·6H₂O and Al (NO₃)₃·9H₂O in distilled water, at various conditions. The products were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy, photoluminescence (PL) spectroscopy, and EDAX analysis. The effects of different parameters such as reaction time and microwave power on the morphology, particle size, and PL properties of the product were studied by SEM images and the PL.     

以橡子为碳源制备的空心磁性碳纳米球及其吸附性能

以橡子为碳源,通过高温煅烧法制备了粒径均匀的磁性空心碳纳米球(MHCNS)。经过HCl浸泡处理可得MHCNS-1,再经HNO_3和NH_3·H_2O处理得MHCNS-2。MHCNS-2粒径均匀,直径为20～40 nm,球壁厚度为3～5 nm。MHCNS-2的尺寸可通过改变镍离子与氢氧化钾的添加量和比例进行调控。通过X射线粉末衍射、扫描电镜、透射电镜、振动样品磁强计等方法对制备的产物进行了表征,进而分析了其生长机制。MHCNS-2对于有机染料亚甲基蓝(MB)的吸附性能的实验结果表明,MHCNS-2具有强吸附性能,当MB溶液浓度为100 mg·L~(-1)时,吸附量可以达到185 mg·g~(-1)。MHCNS对布洛芬的载药释药实验结果表明,MHCNS-2载药率可达44%,释药率达70%,有着良好的载药与释药能力。     

Synthesis,structural characterization and reactivity of manganese tungstate nanoparticles in the oxidative degradation of methylene blue

Nanoparticles of manganese tungstate (MnWO₄) were prepared via an impregnation method using Mn(NO₃)₂·4H₂O and WO₃ as a source of Mn and W, respectively. The morphology of the manganese tungstate nanoparticles was studied in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). MnWO₄ nanoparticles showed severe catalytic performances for the degradation of organic dye (methylene blue, MB) in the presence of tert-butyl hydrogen peroxide, TBHP, as the oxidant at room temperature in water.     

Design and preparation of high-aspect-ratio zinc borate whiskers and their effects on mechanical properties of PP nanocomposite

Well-dispersed, high-aspect-ratio 4ZnO·B₂O₃·H₂O whiskers (4ZnO·B₂O₃·H₂O_HARw) were synthesized by a facile hydrothermal method with the aid of ZnSO₄·7H₂O. The formation mechanism was investigated, and the results showed that Zn²⁺ and SO ₄ ^2? ions played a crucial role in the control of 4ZnO·B₂O₃·H₂O_HARw extended along [010] direction. X-ray diffraction (XRD) analysis, high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), and thermogravimetry (TG)-differential scanning calorimetry (DSC) results confirmed that the powder was 4ZnO·B₂O₃·H₂O. Scanning electron microscopy (SEM) and TEM showed that the average aspect ratio of the product was about 100. Nanocomposites of surface-modified 4ZnO·B₂O₃·H₂O_SM-HARw/PP were prepared and their mechanical properties measured. The results suggested that the mechanical properties of 4ZnO·B₂O₃·H₂O_SM-HARw/PP composites were superior to composites made with low-aspect-ratio whiskers (4ZnO·B₂O₃·H₂O_SM-LARw), which displayed poorer mechanical properties even at low addition.