磷酸铋纳米棒的可控合成及其光催化性能

采用水热法合成了形貌可控的磷酸铋纳米棒光催化剂,并以亚甲基蓝(MB)为探针研究了其光催化活性.利用粉末X射线衍射(XRD),透射电镜(TEM)和紫外-可见漫反射光谱(UV-VisDRS)对产物进行了表征.研究发现甘油含量、水热时间、水热温度及前驱体浓度会影响磷酸铋纳米棒的形貌及结构.甘油含量和前驱体浓度主要影响产物形貌.随着甘油含量的增加,产物的长径比先增大后减小.前驱体浓度越低,所得BiPO4纳米棒的尺寸越小,长径比越大.水热时间短时,产物结晶度差,且为六方相,时间延长后转化为单斜相.水热温度过低或过高均不利于完美晶体的形成,160°C时产物的结晶度最高.实验结果表明:BiPO4纳米棒在紫外光下具有良好的光催化性能,其光催化活性受长径比和尺寸大小影响的总体趋势是长径比越大,尺寸越小,其光催化活性越强.结晶度对BiPO4的光催化性能影响较大,结晶度越高,其光催化活性越好.单斜相BiPO4的光催化活性较六方相的强.     

羟基磷酸铜的快速绿色合成

通过研究羟基磷酸铜的合成条件, 提出了一种快速绿色的新合成方法, 在不使用有机胺和减少磷酸使用量的条件下, 降低水热晶化的温度, 缩短了合成所需要的时间. 同时对所制得样品的苯酚羟化催化活性进行了表征.     

氧化铜纳米晶的合成及性能研究

通过水热方法,合成出CuO纳米片,类纳米花等纳米结构,X光衍射表明样品为单斜CuO,透射电镜和高分辨透射电镜表征了样品的形貌和尺寸,观察到CuO纳米晶是由小的晶粒聚集而成的多晶结构。同时讨论了实验中各实验参数在合成CuO纳米晶时所起的作用： KOH具有促进CuO结晶的作用;十六烷基三甲基溴化铵可以控制反应产物尺寸;柠檬酸钠能够影响纳米粒子的排布规则程度,从而进一步影响CuO纳米晶的形貌和尺寸。另外我们还研究了CuO纳米片的光学性能和氮气吸附性质。     

原硅酸镉纳米线的合成与表征

硅酸盐因其基本结构单元[SiO4]四面体可通过共用顶点连接成各种结构形式,易形成具有大比表面积的多孔结构,且具有良好的热稳定性和化学稳定性,目前已广泛用于选择性催化、分子筛、气体的吸附与分离等领域．另外,硅酸盐还是一类优良的发光材料基质．如Mn^2 或其它稀土离子激活的Zn2SiO4、Mg2SiO4和CdSiO3等．由于原料来源广泛和价格低廉．硅酸盐的研究已引起人们的关注．     

Temperature-controlled Hydrothermal Synthesis of Copper(I or II) Coordination Polymers via a Variety of Copper Coordination Modes

Two 1D coordination polymers Cu₂^I(C₆N₃H₄)₂(1) and Cu^II(C₆N₃H₄)₂·H₂O(2) based on benzotriazole(Bta) were hydrothermally synthesized by controlling the crystallization temperature. Single-crystal X-ray diffraction (XRD) analyses reveal that compound 1 is a 1D tubular structure constructed from two types of 1D chains {-Cu-N=N-N-}_n, where the Cu(I) ions adopt linear, triangular, and tetrahedral coordination modes to connect two types of Bta ligands via π-π interaction inside the tubular-like chain. For compound 2, the Cu(II) ions assume a quadrilateral coordination mode linking to the Bta ligands to give 1D straight chains, which stacks through π-π interactions to construct a 2D layer structure. Further characterizations including elemental analyses, infrared IR spectra, thermogravimetric(TG) analyses and luminescence properties have been done.     

铜纳米线的液相制备及其表面修饰研究进展

在现代纳米科学技术领域中,铜纳米线由于具有独特的光学、电学、力学和热学性质而成为制备透明柔性导电电极的优良材料。铜价格低廉,自然存储量较大,是实际应用中替代贵金属的理想材料。然而,将铜离子还原为单质铜比较困难,且单质铜非常容易被氧化,这成为应用中亟需解决的关键问题。如何制备单分散、稳定且具有抗氧化性的铜纳米线也成为该领域的研究热点。在各种制备铜纳米线的方法中,液相还原法不仅可以解决以上问题,且该方法具有制备条件限制少、成本低、简单易行等优点而被广泛应用于铜纳米线的大量合成。本文从铜纳米线的研究背景和研究价值入手,首先综述了不同（光滑或粗糙、单晶或孪晶）铜纳米线的液相制备方法及其生长机制。讨论了铜纳米线的氧化及其抗氧化表面包覆问题。最后对铜纳米线的研究意义和应用前景做出展望。     

Electrostatically Dissipative Polystyrene Nanocomposites containing Copper Nanowires

Summary: A scalable synthesis of copper nanowires by alternating current electrodeposition into porous aluminium oxide was used to produce multigram quantities of 16 nm diameter by >2 µm long nanowires. Polystyrene nanocomposites were prepared by solution processing. The composites containing unpassivated nanowires were non‐uniformly dispersed and showed electrical percolation at ≈2 vol.‐% Cu loading, while the composites containing HSC₁₈H₃₇‐passivated nanowires were uniformly dispersed, but remained resistive up to at least 10 vol.‐% Cu loading.

Copper nanowires prepared by alternating current electrodeposition into porous aluminium oxide templates.     

桥连氧化钨纳米线的可控合成及气敏性质

The rapid development of industrialization has resulted in severe environmental problems. A comprehensive assessment of air quality is urgently required all around the world. Among various technologies used in gas molecule detection, including Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, mass spectroscopy (MS), electrochemical sensors, and metal oxide semiconductor (MOS) gas sensors, MOS gas sensors possess the advantages of small dimension, low power consumption, high sensitivity, low production cost, and excellent silicon chip compatibility. MOS sensors hold great promise for future Internet of Things (IoT) sensors, which will have a profound impact on indoor and outdoor air quality monitoring. The development of nanotechnology has significantly enhanced the development of MOS gas sensors. Among various nanostructures like nanoparticles, nanosheets and nanowires, the emergence of quasi-one-dimensional (q1D) nanowires/nanorods/nanofibers, with unique q1D geometry (facilitating fast carrier transport) and large surface-to-volume ratio, potentially act as ideal sensing channels for MOS sensors with extremely small dimension, and good stability and sensitivity. These structures have thus been the focus of extensive research. Among the various MOS nanomaterials available, tungsten oxide (WO_3-x, 0 ≤ x < 1) nanowires feature the characteristic properties (multiple oxidation states, rich substoichiometric oxides with distinct properties, photo/electrochromism, (photo)catalytic properties, etc.), and unique q1D geometry (single-crystalline pathway for fast carrier transport, large surface-to-volume ratio, etc.). WO_3-x nanowires have broad applications in smart windows, energy conversation & storage, and gas sensing devices, and have thus become a focus of attention. In this paper, the fundamental properties of tungsten oxide, synthesis methods and growth mechanism of tungsten oxide nanowires are reviewed. Among various (vapor-liquid-solid (VLS), vapor-solid (VS) and thermal oxidation) growth methods, the thermal oxidation method enables an in situ integration of WO_3-x nanowires on predefined electrodes (so-called bridged nanowire devices) via the oxidation of lithographically patterned W film at relatively low growth temperature (~500 ℃) because of interfacial strain, defects and oxygen on the surface of the W film. The novel bridged nanowire-based sensor devices outperform traditional lateral nanowire devices in terms of larger exposure area, low power consumption via self-heating, and greater convenience in device processing. Recent progress in bridged WO_3-x nanowire devices and sensitive NO_x molecule detection under low power consumption have also been reviewed. Power consumption of as low as a few milliwatts was achieved, and the detection limit of NO₂ was reduced to 0.3 ppb (1 ppb = 1 × 10^-9, volume fraction). In situ formed bridged WO_3-x nanowire devices potentially satisfy the strict requirements of IoT sensors (small dimension, low power consumption, high integration, low cost, high sensitivity, and selectivity), and hold great promises for future IoT sensors.     

Synthesis and Characterization of ZnO Nanowires

Zinc oxide is a wide bandgap (3.37 eV) semiconductor with a hexagonal wurtzite crystal structure. ZnO prepared in nanowire form may be used as a nanosized ultraviolet light-emitting source. In this study, ZnO nanowires were prepared by vapor-phase transport of Zn vapor onto gold-coated silicon substrates in a tube furnace heated to 900 ?C. Gold serves as a catalyst to capture Zn vapor during nanowire growth. Size control of ZnO nanowires has been achieved by varying the gold film thickness…     

银纳米线的制备及电催化还原氧性能研究

分别以聚乙烯基吡咯烷酮(PVP),乙二醇作为软模板和还原剂,采用不同晶种(AgCl、Ag)快速合成了银纳米线.通过SEM和TEM表征,证明合成银纳米线材料形貌均一,颗粒含量很少.并且发现以AgCl为晶种合成的银纳米线长径比为200左右(SNWH),而以Ag为晶种合成的长径比为30左右(SNWL).以银纳米线作为电催化氧...     

液固相水热法制备氧化硅纳米线

利用液固相水热反应方法, 以硅溶胶为硅源, 在三价铁辅助下与乙二胺的水溶液在180 ℃反应4 d后生成具有P21212空间群结构的单晶氧化硅纳米线. 用扫描电子显微镜、透射电子显微镜和多晶X射线衍射对制备的样品进行了表征, 系统研究了有机胺、金属盐、反应时间及反应温度等条件对氧化硅纳米线生长的影响. 结果表明, 随着有机胺碳链的增长, 产物形貌逐渐由纳米线转变为纳米片; 金属阳离子的存在对纳米线形貌有较大的影响, 而阴离子的存在并不影响纳米线的生成; 过低的铁含量导致反应进行不完全, 而过多的铁盐加入则会导致反应中剩余铁氧化物吸附到氧化硅纳米线表面, 进而影响到产物纯度; 反应时间延长及反应温度的提高都有利于氧化硅纳米线的生长. 最佳反应条件为: 有机胺为乙二胺, 硝酸铁为铁源, 硅溶胶为硅源, 硅/铁摩尔比为1∶0.4, 乙二胺与水的体积比为8∶5, 温度为180 ℃.     

疏水性杂化分子筛的控制合成及催化应用

以乙基三乙氧基硅烷和甲基三乙氧基硅烷为有机硅源, 分别通过转动和静态干胶转化法一步合成出乙基和甲基功能化杂化分子筛并对其进行了表征. 通过对合成路线、 有机基团碳链长度、 凝胶配比等的调变, 实现了对杂化分子筛疏水性的有效调控, 合成出水接触角为124°的疏水性杂化分子筛. 以疏水性杂化分子筛为载体制备的Ru负载催化剂在催化苯酚加氢反应中表现出优异的催化性能, 这归因于疏水/亲油的催化剂表面有利于苯酚分子在催化剂表面的富集进而促进反应的进行.     

Pd纳米晶的调控合成及其在燃料电池中的应用

贵金属Pd纳米晶体的催化性能与其表面结构有着密切联系。基于目前Pd多面体纳米晶体可控合成技术的发展,Pd纳米晶体催化性能的进一步优化及其在催化领域的应用前景依然广阔。本文主要阐述了关于Pd多面体纳米晶的制备及其作为电催化剂在燃料电池中应用的最新研究进展。在介绍纳米晶体的生长机理及其表面结构与晶体形状的关系之后,重点描述了Pd多面体纳米晶体常见的几种制备方法,概述了Pd多面体纳米晶体作为催化剂在燃料电池阴极和阳极中的应用。最后总结展望了Pd多面体纳米晶体作为催化剂的研究方向及其发展前景。     

Hydrothermal Synthesis of Brucite Type Copper Hydroxide Squarate [Cu3(OH)2(C4O4)]·4H2O

Herein we report synthesis of a new brucite type copper hydroxide squarate, Cu₃(OH)₂(C₄O₄)₂·4H₂O [P2₁/c, a = 5.6437(4) Å, b = 12.8357(9) Å, c = 9.1507(6) Å, β = 95.892(1)° and Z = 2] by hydrothermal method, and its characterization by single crystal diffraction analysis as well as by IR spectroscopy. The rather wide spread of Cu–O bond lengths, can be primarily rationalised by the Jahn‐Teller effect, and secondarily by the connectivities of the CuO₆ octahedra.     

球形、花形和线状钒酸铋的可控合成及光催化性能

通过无模板、无助剂的可控水热法, 制备出球形、花形和线状钒酸铋(BiVO₄), 研究了其光学和可见光催化性能. 通过X射线衍射(XRD)和透射电镜(TEM)观测其结构和形貌特征. XRD谱线显示, 所制备的样品为单斜晶体结构. TEM结果表明, 通过控制水热过程的反应参数可以得到不同形貌的纳米粉体. 基于不同条件下制备的样品的微结构分析, 提出了这些不同形貌的形成机制. 紫外-可见漫反射光谱(UV-Vis DRS)表明BiVO₄样品的带隙能约为2.19-2.33 eV. 利用可见光(λ>420 nm)照射下的罗丹明B(RhB)降解实验评价了BiVO₄样品的光催化性能. 结果表明, BiVO₄的光催化活性比商用TiO₂催化剂P25 和掺氮TiO₂ (N-TiO₂)高得多. 所制备的球形BiVO₄光催化效率最高, 经可见光照射180 min, RhB溶液的降解率可达100%. 系统地研究了结构和形貌对不同pH值下制备的BiVO₄样品光催化活性的影响.     

Facile Chemical Conversion Synthesis and Luminescence Properties of Uniform YF3 Nanowires

Well-dispersed YF₃ nanowires were synthesized by a designed hydrothermal conversion method with Y(OH)₃ nanowires as precursor. Various equipments were used to characterize the samples. The results show that Y(OH)₃ nanowires precursor was prepared through a simple hydrothermal process, which then served as the precursor for the fabrication of YF₃ nanowires by a hydrothermal process. The whole process was carried out under aqueous conditions without any organic solvent, surfactant or catalyst. The conversion process from Y(OH)₃ precursor to YF₃ nanowires was investigated by time-dependent experiments. The possible formation mechanism of YF₃ nanowires was presented in detail. Under UV excitation, 5%(mass fraction) Eu³⁺ or 5%(mass fraction) Tb³⁺ doped YF₃ samples exhibit strong red or green emission, corresponding to the characteristic lines of Eu³⁺ and Tb³⁺, respectively. Moreover, the luminescence colors of the Eu³⁺ and Tb³⁺ codoped YF₃ samples can be tuned from red, yellow and green-yellow to green by simply adjusting the relative doping concentrations of the activator ions under a single wavelength excitation, which might find potential applications in the fields of, such as, light display systems and opto- electronic devices.     

Hydrothermal Synthesis of Nanorods and Nanowires of Mg/Al Layered Double Hydroxides

Layered double hydroxides (LDHs) are a class of synthetic anion clays, characterized by the formula[MⅡ1-xMⅢx (OH)2]x (An- )x/n·yH2O (where M =metal and A = anion, usually carbonate)[1-3]. A large number of LDHs with a wide variety of M Ⅱ-M Ⅲ cation pairs including M Ⅰ-M Ⅲ ( e. g. , Li-Al ) and M Ⅱ-MⅣ( e. g. , Co-Ti) have been reported. Thus the identities of the cations(MⅠ , MⅡ , MⅢ and MⅣ) and the interlayer anion (An-) together with the value of the stoichiometric coefficient (x) may vary widely, giving rise to a large class of isostructural materials.     

GaSb纳米线的CVD可控制备及其光学表征

采用CVD法合成GaSb纳米线,并分析生长时间对其长度的影响,随后对其进行光学表征.实验过程中,分别采用喷金法和滴金法对硅片进行预处理,再置于相同条件下制备GaSb纳米线;之后对其进行表征分析,根据扫描电子显微镜（SEM）表征结果证实,两种方法制备的纳米线都满足VLS生长机制.且发现GaSb纳米线的生长长度,可以通过改变其生长时间来进行控制.通过该纳米线的透射电子显微镜图（TEM）、X射线衍射图（XRD）等结构表征,表明该纳米线为结晶品质优良的立方闪锌矿结构;同时,从GaSb纳米线的拉曼光谱（Raman）及光致发光谱（PL）可以反映该纳米线具有优良的光学性质.由此证明,采用CVD法制得的纳米线光学性质优异,且可以实现可控制备.     

碳热还原制备不同形貌的碳化硅纳米线

以酚醛树脂为碳源，正硅酸乙酯为硅源，硝酸镧和表面活性剂为调控剂，通过溶胶-凝胶和碳热还原反应制备了不同形貌的碳化硅纳米线。采用X射线衍射、扫描电子显微镜、透射电子显微镜和X射线散射能谱对所制备的碳化硅纳米线进行表征。结果表明，通过此方法所制备的碳化硅纳米线均为立方结构的β-SiC，分别具有直线状、竹节状和链珠状、分枝状等不同形貌。金属催化剂和表面活性剂对碳化硅纳米线的结构和形貌变化有重要影响。     

溶剂热制备氧化锌纳米线

ZnO nanowires were synthesized mildly through an absolute alcohol solvothermal process at 120 ℃ for 12 h using ZnAc₂·2H₂O and NaOH as raw materials and PEG400 as a soft template. The cyrstal structure and morphology of the nanowires were characterized by XRD, SEM, TEM and HRTEM. The results indicate that the diameter of ZnO nanowires is 40 nm, the length can reach 2 μm and the nanowires are of high purity, homogeneity and well crystallinty. The influence of the various factors on the formation of ZnO nanowires and formation mechanism were also discussed.