基于氮掺杂碳纳米颗粒荧光猝灭-恢复方法检测还原型谷胱甘肽

分别以海藻酸钠和色氨酸为碳源和氮源,采用固相法一步合成出了量子产率为47.9%的氮掺杂荧光碳纳米颗粒(N-CNPs)。根据铜离子存在的条件下,N-CNPs荧光强度的恢复情况与还原型谷胱甘肽浓度成正比的关系,建立基于N-CNPs检测还原型谷胱甘肽的新方法。优化了溶液pH及反应时间等条件。在pH 6.0、铜离子浓度30μmol/L条件下,谷胱甘肽在0.2~45μmol/L浓度范围内与N-CNPs荧光恢复强度呈良好的线性关系,检出限为50 nmol/L。方法具有灵敏度高、选择性好、操作简单等优点,可用于实际样品中谷胱甘肽的检测。     

射频磁控溅射制备TiO2-xNx薄膜及其光催化特性研究

利用射频磁控溅射在玻璃衬底上制备了透明TiO2 和 TiO2-x Nx 薄膜样品,通过 X 射线衍射(XRD)、原子力显微镜(AFM)及 UV Vis分光光度计等测试手段表征了样品的结构、形貌和光催化性能。结果表明制备的薄膜为锐钛矿相结构。随着 N2/Ar气流比的增大薄膜样品出现新的物相,吸收光谱向可见光方向展宽,在N2/Ar流量比为 3∶100 时,制备的薄膜在可见光区具有很好的光催化性能。     

氮掺杂TiO_2中空复合微球的制备及可见光光催化性能

为了提高TiO2的可见光光催化性能,以微米级聚苯乙烯微球为模板,钛酸四丁酯为前驱体,三乙胺为氮源,采用静电吸附自组装法制备了粒径为1.20μm、壳层的厚度约为30nm且球形形貌良好的氮掺杂TiO2中空复合微球,采用SEM、XPS、XRD和紫外-可见分光光度计研究了其结构及光催化性能。结果表明:氮进入TiO2晶格内取代了部分O并改变了晶格中Ti和O的化学状态,但对TiO2晶型结构没有明显影响;氮掺杂后的TiO2中空复合微球禁带宽度变窄,氮掺杂TiO2中空复合微球不仅在紫外区有较强的光吸收能力,在可见光区也表现出较强的光响应性,对甲基橙的光催化降解率较Degussa P25型纳米TiO2的明显增强。研究结果对TiO2在光催化领域的应用具有理论指导意义。     

Room-temperature hydrogenation of halogenated nitrobenzenes over metal–organic-framework-derived ultra-dispersed Ni stabilized by N-doped carbon nanoneedles

Ultra-dispersed Ni nanoparticles (7.5 nm) on nitrogen-doped carbon nanoneedles (Ni@NCNs) were prepared by simple pyrolysis of Ni-based metal–organic-framework for selective hydrogenation of halogenated nitrobenzenes to corresponding anilines. Two different crystallization methods (stirring and static) were compared and the optimal pyrolysis temperature was explored. Ni@NCNs were systematically characterized by wide analytical techniques. In the hydrogenation of p-chloronitrobenzene, Ni@NCNs-600 (pyrolyzed at 600 °C) exhibited extraordinarily high performance with 77.9 h^–1 catalytic productivity and > 99% p-chloroaniline selectivity at full p-chloronitrobenzene conversion under mild conditions (90 °C, 1.5 MPa H₂), showing obvious superiority compared with reported Ni-based catalysts. Notably, the reaction smoothly proceeded at room temperature with full conversion and > 99% selectivity. Moreover, Ni@NCNs-600 afforded good tolerance to various nitroarenes substituted by sensitive groups (halogen, nitrile, keto, carboxylic, etc.), and could be easily recycled by magnetic separation and reused for 5 times without deactivation. The adsorption tests showed that the preferential adsorption of –NO₂ on the catalyst can restrain the dehalogenation of p-chloronitrobenzene, thus achieving high p-chloroaniline selectivity. While the high activity can be attributed to high Ni dispersion, special morphology, and rich pore structure of the catalyst.     

微波法制备具有可见光活性的氮掺杂二氧化钛

采用乙二醇作为溶剂，脲为氮源，用微波法制备了氮掺杂的二氧化钛纳米催化剂。采用傅立叶变换红外（FTIR），波长色散谱（WDS），X射线衍射（XRD），X射线光电子能谱（XPS）等对样品的化学组成以及表面基团进行了表征和分析。在模拟太阳光和可见光的条件下对甲基橙进行光催化降解评价，结果表明该催化剂在没有降低二氧化钛紫外区活性的同时具有较高可见光催化活性。     

掺氮TiO_(2-x)N_x薄膜托槽的制备及其性能研究

利用射频磁控溅射制备了氮掺杂TiO2-xNx薄膜托槽,通过X射线衍射(XRD)、扫描电镜(SEM)等测试手段表征了托槽表面薄膜的结构、形貌,并通过原子力显微镜(AFM)、多功能材料表面试验仪等研究了TiO2-xNx薄膜与基底托槽的附着力、TiO2-xNx薄膜托槽的表面粗糙度以及表面摩擦系数。结果表明制备的托槽表面为均一的锐钛矿相结构TiO2-xNx薄膜,晶粒粒径为30nm,纳米TiO2-xNx薄膜托槽表面致密、平整,薄膜与托槽衬底结合紧密、附着性好,托槽表面粗糙度降低,摩擦系数变小,改善了托槽表面性能,为抗菌性研究奠定了基础。     

膨润土负载氮掺杂TiO2光催化剂制备及性能研究

以钛酸四丁酯和氨水为原料,膨润土为载体,采用溶胶-凝胶法制备了膨润土负载掺氮TiO2光催化剂.并利用IR对光催化剂组织结构进行袁征.在可见光下考察了焙烧温度、光催化时间、光催化剂用量、酸度等因素对光催化剂降解亚甲基蓝废水性能的影响.实验结果表明:450℃下焙烧所得的催化剂,用量为1.2 g/L,在碱性条件下常温光照20...     

微管在6H-SiC单晶生长过程中的演化

采用升华法生长调制掺氮的6H-SiC单晶,其[0001]方向纵切片的掺氮条纹表明,晶体的生长前沿由初始生长阶段的凸形逐渐变成了后续生长阶段近似平坦的形状。发现近似平坦的生长前沿有利于单晶质量的提高。透射光学显微镜观察发现,若微管的延伸方向与6H-SiC晶体的[0001]方向偏离角度较大时,微管变得不稳定而离解消失;微管也可终止于六边形空洞或硅滴处。氮元素掺杂可使6H-SiC晶体的晶格发生畸变,可导致产生新微管。     

具有可见光活性的纳米掺氮TiO2制备和表征

用硫酸钛与氨水反应得到TiO2前体,煅烧后制得掺氮TiO2粉体,研究不同反应条件和不同温度下掺氮TiO2的吸光特性和形态结构,结果表明掺氮TiO2在400℃：下加热1h,所得粉体是锐钛矿相结构,粒径约15nm,与未掺杂TiO2相比,吸收边红移22nm,对400-510nm的可见光有一定的吸收率,可见光下对甲基橙的降解表明具有可见光活性。     

Scalable Production of Wearable Solid-State Li-Ion Capacitors from N-Doped Hierarchical Carbon

Smart and wearable electronics have aroused substantial demand for flexible portable power sources, but it remains a large challenge to realize scalable production of wearable batteries/supercapacitors with high electrochemical performance and remarkable flexibility simultaneously. Here, a scalable approach is developed to prepare wearable solid-state lithium-ion capacitors (LICs) with superior performance enabled by synergetic engineering from materials to device architecture. Nitrogen-doped hierarchical carbon (HC) composed of 1D carbon nanofibers welded with 2D carbon nanosheets is synthesized via a unique self-propagating high-temperature synthesis (SHS) technique, which exhibits superior electrochemical performance. Subsequently, inspired by origami, here, wave-shaped LIC punch-cells based on the above materials are designed by employing a compatible and scalable post-imprint technology. Finite elemental analysis (FEA) confirms that the bending stress of the punch-cell can be offset effectively, benefiting from the wave architecture. The wearable solid-state LIC punch-cell exhibits large energy density, long cyclic stability, and superior flexibility. This study demonstrates great promise for scalable fabrication of wearable energy-storage systems.