高分子模板调控不同形貌氧化亚铜的仿生合成

采用聚丙烯酰胺(PAM)为软模板,在CuSO4、Na2SO3体系中调控合成了片状、海胆状、一维线、针状聚集体氧化亚铜晶体。研究了不同浓度Cu2+、不同PAM含量及不同温度对晶体生长的影响。结果表明,PAM促使氧化亚铜异相成核,氧化亚铜形貌随PAM质量分数的变化而变化:当c(Cu2+)=0.5mol.L-1时,PAM质量分数为3.0%(常温引入体系),产物主要为片状晶体;PAM质量分数为1.0%、3.0%时(高温引入体系),分别获得一维线状、海胆状晶体;当Cu2+浓度为0.1 mol.L-1时,体系中高温引入质量分数3.0%的PAM,得到片层状晶体;当Cu2+浓度为0.3、0.4 mol.L-1时,得到针状聚集体氧化亚铜晶体。分别用X射线粉末衍射、冷场发射扫描电子显微镜和激光粒度仪对所制备的产品进行了表征。     

Dual II Heterojunctions Metallic Phase MoS2/ZnS/ZnO Ternary Composite with Superior Photocatalytic Performance for Removing Contaminants

Fabricating a high-performance photocatalyst to efficiently solve serious environmental problems is an urgent affair. Herein, a series of MoS₂/ZnO composites were successfully fabricated through a facile hydrothermal route using Na₂MoO₄, (NH₂)₂CS and urchin-like ZnO as precursors. According to the results of XRD and XPS, it was found that ZnS appeared in MoS₂/ZnO composite; meanwhile, the content was positively correlated with the weight of the precursor (NH₂)₂CS. It should be noted that the morphology and the metallic phase content of MoS₂ grown in situ on the surface of ZnO were affected by the molar ratio of Na₂MoO₄ and ZnO. Benefiting from the special dual II heterojunctions of MoS₂/ZnS/ZnO ternary composite, the material exhibited excellent charge separation and transfer performances. In the photocatalytic measurements, the MoS₂/ZnS/ZnO (Na₂MoO₄:ZnO 1:2 MZ2) composite not only exhibits excellent photocatalytic Cr^VI reduction activity of 42.3×10⁻³ min⁻¹, but also displays remarkable adsorption performance (nearly 32.1 %) for Cr₂ . In addition, the ternary composite shows dominant photocatalytic Cr^VI reduction activities compared to other photocatalysts. This work provides a high-efficient MoS₂/ZnS/ZnO ternary photocatalyst for environmental treatment.     

A simple method to synthesize sea urchin-like polyaniline hollow spheres

Oxidative polymerization of aniline diffusing out from polystyrene hollow spheres with ferric chloride results in the formation of sea urchin-like polyaniline composite hollow spheres, which provide a simple chemical way to assemble conducting polymer nanofibers into complex structure under mild condition.     

三维海胆状二氧化锰微球对电催化氧还原反应的晶型效应

采用水热法和高温煅烧法制备出了3种纯相(α,γ和β)的三维海胆状结构的MnO2微球,并系统地研究了它们的氧还原反应(ORR)性能。研究结果表明,3种MnO2微球的ORR活性依次为:α-MnO2>γ-MnO2>β-MnO2。α-MnO2微球具有最优的ORR性能,其起始电位为0.92 V(vs RHE),在电流密度为-3 mA·cm^-2处的电位为0.77 V(vs RHE)。α-MnO2微球优异的ORR活性主要归因于其具有更多的表面Mn3+和氧空位和更好的导电性。     

海胆状Eu2O3/Ag3VO4复合材料的水热合成及其光致发光性能

以硝酸银和氧化铕为金属源,P123为结构导向剂,乙醇和水为溶剂.本文通过前驱体合成路线,采用水热法得到海胆状Eu2 O3/Ag3 VO4微球,并探讨其合成条件;采用SEM、XRD、XPS等方法对样品进行了表征,并探讨了Eu2 O3/Ag3 VO4海胆状微纳米结构的形成过程.测试结果表明:在反应温度为80℃,反应时间为10 h时,所合成的海胆状Eu2 O3/Ag3 VO4微球直径约为4~5μm.针对合成的样品,研究了海胆状Eu2 O3/Ag3 VO4微球的光致发光性能,并考察Eu3+掺杂量对光致发光性能的影响,当Eu3+掺杂量为4;时,样品具有最好的光致发光性能.     

海胆状金纳米粒子表面形貌对表面增强喇曼散射特性的影响

采用改进的一步还原法合成了多种海胆状金纳米粒子,并对它们的表面增强喇曼散射特性与其表面形貌的关系进行了实验研究.实验表明,合成的海胆状金纳米粒子的直径及表面的尖刺大小可以通过改变加入到氯金酸溶液中的硝酸银的量来调节.当加入到氯金酸溶液中的硝酸银为1μL时,合成的海胆状金纳米粒子的直径最小而尖刺最长.同时测量的紫外-可见-近红外吸收光谱表明,海胆状金纳米粒子的局域表面等离子体共振带会随着加入到氯金酸溶液中的硝酸银量的增加而变宽.此外,通过喇曼标记分子对巯基苯甲酸(4MBA)的喇曼光谱测量发现,较小直径和较长尖刺的海胆状金纳米粒子具有更强的表面增强喇曼散射活性.     

基于疏水滤纸的金纳米花SERS 基底高灵敏检测牛奶中的三聚氰胺

将海胆状金纳米花(gold nanoflowers, GNFs)疏水滤纸基底和表面增强拉曼散射(surface-enhanced Raman scattering, SERS)技术相结合,实现了牛奶中三聚氰胺的高灵敏检测。由左旋多巴还原制备的GNFs拥有许多尖锐突起和尖端可激发强局部电磁场增强(electromagnetic enhancement, EM),产生大量的“热点”,提高SERS检测的灵敏度。采用疏水滤纸作为衬底,改进了纸基衬底上纳米材料分布不均匀的缺点。进而评估了SERS基底的灵敏度、稳定性和重现性。通过对加标牛奶中三聚氰胺的定量检测,在1×10_-3^~1×10_-9 ^mol/L范围内,牛奶中三聚氰胺的浓度对数与SERS强度呈良好的线性关系,检测限低至43 pmol/L,远低于同类检测方法。并且本方法检测实际样品结果与液相色谱法检测结果对比无显著性差异(p>0.05)。GNFs疏水滤纸SERS基底具有高灵敏度、稳定性、重现性和实用性的优点,为牛奶等其他食品中三聚氰胺的定量检测提供了参考价值。     

新型海胆状钨铜自支撑电极的制备及其葡萄糖无酶传感

该文采用方波脉冲法在光滑W70Cu30电极表面快速、高效制备海胆状结构的自支撑电极（U－WCu）,并用于葡萄糖的电化学检测,其表现出比单一纳米铜（N－Cu）更优异的电化学性能。考察了脉冲时间、脉冲频率和电势范围对葡萄糖电催化氧化的影响。采用循环伏安法（CV）比较了U－WCu电极和N－Cu电极在0.1 mol/L NaOH溶液中对葡萄糖的电催化氧化行为,构建了基于U－WCu海胆状电极的无酶电化学传感器。该电极的线性范围宽（2 μmol/L ~ 10 mmol/L）,检出限（S/N = 3）低至0.21 μmol/L,灵敏度高达4 983 μA?mmol?L-1?cm-2。方法有极好的重复性、重现性,良好的抗干扰性,以及长达8周的稳定性,并成功用于葡萄糖注射液中葡萄糖含量的测定。     

Photocatalytic Activity of Radial Rutile Titanium(IV) Oxide Microspheres for Aerobic Oxidation of Organics

Radial rutile TiO₂ nanorod homomesocrystals (TiO₂-NR HOMCs) or the so-called “sea urchin-like TiO₂ microspheres” were synthesized by using a hydrothermal method. TiO₂-NR HOMCs show photocatalytic activity for aerobic oxidative degradation of 2-naphthol under irradiation of UV- and visible light. Furthermore, extremely small iron oxide clusters were formed on the surface of TiO₂-NR HOMCs (FeO_x/TiO₂-NR HOMCs) by the chemisorption-calcination technique to reduce the band gap. The FeO_x-surface modification gives rise to drastic enhancement of the UV- and visible-light activity. Reversed double-beam photoacoustic spectroscopy measurements were performed for TiO₂-NR HOMCs and FeO_x/TiO₂-NR HOMCs to obtain the ERDT (energy-resolved distribution of electron traps)/CBB (conduction-band bottom) patterns. The ERDT/CBB pattern of TiO₂-NR HOMCs consists of two components derived from rutile (C1) and amorphous TiO₂ (C2). In the pattern, the surface electron traps in C2 exist near the CBB to be removed by the FeO_x-surface modification. By taking this finding into consideration, the striking surface modification effect is ascribable to the electrocatalytic activity (or the action as an electron reservoir) of the FeO_x clusters for multiple ORR, the suppression of recombination, and the increase in the visible-light harvesting efficiency.