SnO2/Zn2SnO4纳米结构的制备及光谱性质

采用自蔓延高温合成-喷射法制备了SnO2纳米线和SnO2/Zn2SnO4纳米结构,利用XRD、SEM、UV-vis和FT-IR对其物相、形貌和谱学性质进行了表征。结果表明:SnO2纳米线凝胶对紫外-可见光的透光度随着SnO2纳米线加入量的增加而增加,但是,SnO2/Zn2SnO4凝胶对紫外-可见光的透光度却随着SnO2/Zn2SnO4的增加而减少;与SnO2纳米线相比,SnO2/Zn2SnO4在1090,1430,1640,3450cm-14个特征波长附近对红外光谱的选择吸收率明显提高,因而对H2O、CH4、CO和CO2等气体的敏感性将显著增强。     

水热法制备F/Mn共掺杂SnO2纳米粒子

本文采用水热法制备了具有金红石结构的F-Mn共掺杂SnO2纳米粒子,研究了碱源、pH值、掺杂剂、表面活性剂、煅烧温度对F/Mn共掺杂SnO纳米粒子晶相、微观形貌、分散性和光学性能的影响。采用X射线衍射（XRD）、扫描电镜（SEM）和紫外/可见/近红外分光光度计对F-Mn共掺杂SnO2纳米粒子进行了表征。结果表明,该方法可以获得较高的结晶度、较小的粒径和分散良好的F-Mn共掺杂SnO2纳米粒子。F-Mn共掺杂SnO2涂层具有较好采光的同时有较高的近红外屏蔽性能,其中可见光透过率约为90%,近红外阻隔率约为93%左右。     

SnO2实心球制备及其在电接触材料中应用

以结晶四氯化锡(SnCl₄.5H₂O)和氢氧化钠(NaOH)为原料,采用水热法在180℃下反应25h成功地制备了SnO₂实心微球,并通过高能球磨法将SnO₂实心微球与化学Ag粉混合,并进行压制、烧结等工艺处理。考察了表面活性剂种类、水热时间及PH值对SnO₂微球形貌的影响,通过扫描电子显微镜(SEM)、X射线衍射仪(XRD)、透射电子显微镜(TEM)和维氏硬度计、电导率仪等分析手段对产物的形貌、结构及物理性能等进行了表征。结果表明,以十六烷基三甲基溴化铵(CTAB)为表面活性剂,反应温度为180℃、PH值13时,可以得到分散性良好的SnO₂微球,微球为实心状,球形度好,尺寸在1~4 μm之间;与Ag粉经压制、烧结后片材的电阻率为3.18 μΩ.cm、密度为71.5 g.cm_-3, 均比普通纳米SnO₂粉体与Ag制得的样品性能好。     

Pd掺杂SnO2纳米颗粒的合成、表征和气敏特性（英文）

利用非模板水热法合成了Pd掺杂的SnO2纳米颗粒,并利用透射电镜(TEM)、X射线衍射(XRD)和X光电子能谱(XPS)表征了Pd掺杂对晶体结构、表面形貌、微观结构、热稳定性和表面化学状态的影响。研究发现:水热过程中Pd掺杂对形成的SnO2纳米颗粒大小几乎没有影响,在500°C以下的煅烧过程中,掺杂的Pd可以有效抑制颗粒的生长,但在700°C以上时颗粒生长迅速。XPS结果显示合成样品中Pd的化学状态有三种:Pd0、Pd2+和Pd4+,其中的主化学状态Pd4+有效促进了气敏性能的提高。为了同时提高气敏性能和热稳定性,Pd的最佳掺杂量为2.0%?2.5%(摩尔分数)。     

SnO2/TiO2纳米管阵列对304不锈钢的阴极保护效果

目前,就SnO2/TiO2复合薄膜对不锈钢的光生阴极保护效果的研究有待深入。以两步阳极氧化法在钛箔表面制备TiO2纳米管阵列膜,并将其浸渍在不同浓度的SnO2溶液中,得到了SnO2/TiO2复合纳米管阵列材料。采用扫描电镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)研究了其表面形貌、晶型,用电化学方法研究了SnO2/TiO2复合纳米管阵列对304不锈钢的光生阴极保护特性及耐腐蚀性能。结果表明:TiO2纳米管排列规整,孔径约80~150 nm;以0.5 mol/L SnO2溶胶制备的SnO2/TiO2半导体供给外电路的电子数最高;在紫外光照1 h时,TiO2和SnO2/TiO2均对304不锈钢有一定的光生阴极保护作用;闭光后SnO2/TiO2光生电极在较长时间内维持较低电位,低于其在3.5%NaCl溶液中的自腐蚀电位,延时阴极保护作用可以达到8.5 h。     

溶液燃烧合成制备Ni-Y2O3纳米复合粉末（英文）

采用溶液燃烧合成和氢气还原两步法制备具有超细Y2O3弥散相的Ni-Y2O3纳米复合粉末。通过DTA-TG分析探讨燃烧机理,使用场发射扫描电镜、透射电镜和X射线衍射分析技术表征燃烧得到的粉末形貌和Ni-Y2O3纳米复合粉末的形貌和物相。详细讨论原料中硝酸镍与尿素配比对燃烧得到的粉末形貌、物相和比表面积的影响。高分辨透射形貌分析结果显示合成得到的Ni-Y2O3纳米复合粉末中均匀分布的Y2O3弥散相的尺寸在10 nm左右,并且在放电等离子烧结致密化后并未明显长大。     

固相-水热法制备LiFePO4-Li3V2（PO4）3复合材料及其电化学性能（英文）

分别采用固相-水热法和球磨法制备磷酸亚铁锂-磷酸钒锂复合正极材料(LiFePO4-Li3V2(PO4)3)。电化学性能测试表明,LiFePO4-Li3V2(PO4)3复合正极材料的电化学性能远远高于 LiFePO4和 Li3V2(PO4)3单独作为正极材料的性能,并且以固相-水热法制备的复合材料性能优于以球磨法制得的复合材料。研究发现 LiFePO4-Li3V2(PO4)3复合材料有 4 个氧化还原峰,相当于 LiFePO4 和 Li3V2(PO4)3 氧化还原峰的叠加。采用固相-水热法制备的LiFePO4-Li3V2(PO4)3 复合材料形貌较为规则,且有新相物质产生,这是导致其电化学性能较好的原因。     

水热法合成MoO3纳米带对其光吸收特性的影响（英文）

以仲钼酸铵为钼源,硝酸为沉淀剂,在强酸性反应体系通过水热法合成了MoO3纳米带。利用XRD、SEM、TEM和SAED对试样进行分析,结果表明:在水热法体系中合成MoO3纳米带时,随着pH值的增加和反应温度的升高,它们都有利于合成MoO3纳米带。在pH值为3、反应温度为240℃和反应时间96h下合成径向小于100nm的晶体MoO3纳米带,此MoO3纳米带的径向分布较不均匀。对不同条件下水热法合成的MoO3进行紫外可见光的吸收光谱分析可得,随着pH值的增加和反应温度的升高,获得的MoO3的光吸收能力是逐渐增加的。特别是MoO3纳米带具有良好的光吸收能力。     

水热法对合成WO3纳米棒形貌和光敏特性的影响（英文）

以钨酸钠为原料,硫酸钾为辅助盐,在强酸性反应体系通过水热法合成了WO3纳米棒。利用XRD、SEM、TEM和SAED对试样进行分析,结果表明:在水热法体系中合成WO3纳米棒时,随着pH值的增加和反应温度的升高,它们都有利于合成WO3纳米棒。在pH值为1.5、反应温度为240℃和反应时间48.0h下合成径向小于100nm的晶体WO3纳米棒,此WO3纳米棒径向分布较均匀。对不同条件下水热法合成的WO3纳米棒进行紫外可见光的吸收光谱分析可得,随着pH值的增加和反应温度的升高,获得的WO3纳米棒的紫外光吸收能力逐渐增强,并且具有良好的紫外光吸收能力。     

纳米SnO2磨料的制备及其在钌化学机械抛光中的应用（英文）

利用固相反应法制备纳米二氧化锡磨料并研究了制备条件对平均粒径的影响。结果表明,在500℃/4h条件下制得的纳米二氧化锡粉体在水中有良好的分散性和稳定性。利用自制的抛光液对高纯钌片进行化学机械抛光,与二氧化硅磨料抛光液比较,材料去除速率和表面粗糙度都降低。当抛光液中含1%(质量分数,下同)二氧化锡、1%过硫酸铵、1%酒石酸和3mmol/L咪唑,pH=8.0,抛光压力为17.24kPa时,材料去除速率(MRR)和表面粗糙度(Ra)分别为6.8nm/min和4.8nm。     

NaBH_4的水性还原法制备纳米铜颗粒(英文)

在碱性溶液中用NaBH4还原Cu2+制备纳米铜颗粒,研究NaBH4浓度和滴加速率对Cu纳米颗粒制备的影响。反应的最佳条件是:0.2mol/LCu2+,溶液pH12,温度313K,1%明胶作为分散剂,将0.4mol/LNaBH4溶液以50mL/min的速率加入CuSO4溶液中。氨水是最佳的络合剂。采用一系列实验研究不同时间点的反应进程。     

Preparation and electrochemical performance of nanosized Co3O4 via hydrothermal method

The hydrotalcite-type cobalt compounds were prepared through oxidation of Co（OH）2 gel using NH4OH as precipitating agent and H2O2 as oxidant. These hydrotalcite-type cobalt compounds were transformed into Co3O4 through hydrothermal decomposition with nanostructural deformation. The precursor and product were characterized by Fourier-transform infrared（FT-IR） spectrum, X-ray diffractometry（XRD） and transmission electron microscopy（TEM）. The electrochemical performances of as-prepared nanosized Co3O4 as anode materials in lithium-ion batteries were tested by charge-discharge test in the voltage range of 0-3.0 V. The influence of morphology of Co3O4 particle on the capacity and cycling performance was studied. The results show that the shape and size of the final product can be controlled by altering cobalt sources. The irregular cubic Co3O4 with the average particle size of about 10 nm shows the best electrochemical performance. After 10 charge-discharge cycles, the specific charge capacity retains 555 mA.h/g.     

Co掺杂ZnAl2O4纳米颗粒的制备与光学性质研究

以CTAB为表面活性剂,采用水热法成功制备了不同掺杂比例的Zn1-xCoxAl2O4（x=0,0.20,0.40和0.60）纳米晶。并对样品的晶体结构、形貌、化学成分、价态和光学性能进行表征。实验结果表明,本方法所制备的不同掺杂浓度的Zn1-xCoxAl2O4纳米颗粒为尖晶石结构,晶化程度良好。根据XRD数据计算了晶胞参数a、晶格间距dhkl、晶粒尺寸D,随着掺杂Co离子浓度的增加,均表现为减小趋势。XPS能谱显示大多数Co离子占据四面体中心位置,但有少量的Co离子占据八面体中心位置。随着掺杂Co离子浓度的增加,紫外吸收光的强度逐渐增加。     

Preparation of antimony-doped nanoparticles by hydrothermal method

Antimony-doped tin oxide (ATO) nanoparticles were prepared by the mild hydrothermal method at 200℃ using sodium stannate, antimony oxide, sodium hydroxide and sulfuric acid as the starting materials. The doped powders were examined by differential thermal analysis(DTA), X-ray diffractometry(XRD) and transmission electron microscopy(TEM). The doping levels of antimony were determined by volumetric method and iodimetry.The results show that antimony is incorporated into the crystal lattice of tin oxide and the doping levels of antimony in the resulting powders are 2.4%, 4.3%and 5.1%(molar fraction). The mean particle size of ATO nanoparticles is in the range of 25 - 30 nm. The effects of antimony doping level on the crystalline size and crystallinity were also discussed.     

Solvothermal synthesis and characterization of size-controlled Fe3O4 nanoparticles

Size-controlled Fe₃O₄ nanoparticles were prepared via a facile solvothermal method by using the mixed surfactants of SDS and PEG as protective reagents. The sizes of the nanoparticles can be varied from 15 to 190 nm by adjusting the experimental conditions. The influences of the protective reagents, reaction time, the initial concentration of the reactant, molar ratio of FeCl₃ and protective reagents on the size of the produced nanoparticles were studied. The size and morphology of the products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and scanning electron microscopy (SEM).     

N-doped carbon nanotubes synthesized in high yield and decorated with CeO2 and SnO2 nanoparticles

Nitrogen doped multiwalled carbon nanotubes (CN_xNTs) with high yield and purity have been successfully prepared from n-propylamine precursor with Co_xMg_1−xMoO₄ catalyst. The maximum yield of the CN_xNTs is 920%. SnO₂ and CeO₂ nanoparticles are decorated on the surface of CN_xNTs without any acid treatment due to the inherent interface activity. The TEM images reveal that SnO₂ and CeO₂ nanoparticles were anchored on the surface of the CN_xNTs uniformly, and the XPS results indicate that the doped nitrogen atoms of CN_xNTs play significant roles in immobilizing SnO₂ and CeO₂ nanoparticles, and the mechanism of the composite process has been discussed. The electrooxidation performance of the composites for NO at the modified electrodes was investigated. The CN_xNTs-based composites show greater activity and sensitivity than the conventional CNTs-based composites for NO electrooxidation, which render them excellent electrode materials for NO detection and other potential applications.     

纳米LiInO2光催化剂的溶胶-凝胶法制备与表征

本文利用溶胶-凝胶法制备了LiInO₂纳米材料,采用X-射线衍射(XRD)、扫描电镜(SEM)和紫外-可见吸收光谱等测试手段,研究了制备条件对LiInO₂微观结构的影响因素,并以亚甲基蓝为目标降解物研究了LiInO₂的光催化性能。研究结果表明：制备的LiInO₂纳米粒子具有LiFeO₂的晶型,颗粒尺寸约50-100纳米,制备样品的焙烧温度对其结构和性能产生了明显地影响,在氙灯(300W)照射90 min条件下,纳米LiInO₂对亚甲基蓝的光催化降解率达92%,活性位点捕获实验表明光生空穴在降解亚甲基蓝的机制中占主导作用。     

Catalytic effect of Ni nanoparticles on the desorption kinetics of MgH2 nanoparticles

Mg and Ni nanoparticles were prepared by hydrogen plasma-metal reaction (HPMR). MgH₂ nanoparticles were obtained by hydriding the Mg nanoparticles. Hydrogen storage kinetics of the MgH₂ nanoparticles doped with different amount of Ni nanoparticles was investigated by differential scanning calorimetry (DSC) and hydrogen desorption rate measurements. The obtained samples show superior hydrogen storage kinetics. 6.1 wt% hydrogen is desorbed in 10 min at 523 K under an initial pressure of 0.01 bar of H₂ when the proportion of Ni nanoparticles is 10 wt%. The desorption rate increases when enhancing the amount of catalyst. However, the activation energy of desorption does not decrease any more when the amount of Ni exceeds a value. The enhanced desorption kinetics are mainly attributed to the accelerated combination process of hydrogen atoms by the Ni nanoparticles on the surface of MgH₂.