掺氮高荧光碳点的一步法制备及对痕量Hg(Ⅱ)离子的选择性检测

采用一步水热法制备了一种水溶性的、具有良好荧光性能的掺氮碳量子点(N-碳点),其尺寸大小均匀,约为7 nm。N-碳点的荧光强度随N的掺杂量、水热反应温度、溶液的pH值而改变。在最佳反应条件下所制备的N-碳点的荧光量子产率高达24.4%。该N-碳点作为一种简单、低成本的荧光探针用于检测痕量Hg²⁺,具有高选择性和高灵敏度的特点,其最低检测极限可达到0.02 μmol·L^-1 (4.012 ng)。     

量子态选择的分子离子解离动力学：阈值光电子-光离子符合成像技术的应用

阈值光电子一光离子符合速度成像技术通过对光电子和符合的光离子同时进行速度聚焦控制,大幅提高了电子和离子的收集效率和离子平动能分辨率,成为开展气相分子光电离和光电离．解离动力学研究的有效工具．利用该技术,我们精确地测量了分子的电离能、离子出现势等重要参数,并且开展了若干具有量子态或内能选择的离子解离动力学研究,描绘了相关势能面存在浅势阱等重要动力学特征,讨论了不同振动态和电子态的激发对解离机理和产物通道的重要影响．     

还原氧化石墨烯/碳纳米管/Co_3O_4三元复合材料的制备与电化学性能

将低温水热反应和低温热处理相结合,制备了含还原氧化石墨烯(RGO)、碳纳米管(CNTs)和Co3O4的三元纳米复合材料RGO-CNTs-Co3O4;利用X射线衍射仪、扫描电子显微镜、透射电子显微镜分析了合成产物的相组成和微观结构,分析了其形成过程;并利用电化学测试装置测定了其作为锂离子电池负极材料的电化学性能.结果表明,在合成反应过程中,氧化石墨烯被还原剂肼还原为石墨烯,同时在石墨烯和CNTs表面生成氢氧化钴;再经低温热处理得到RGO-CNTs-Co3O4三元复合材料.Co3O4纳米颗粒均匀分散在由RGO片层和CNTs组成的三维网络结构中;这种三维网络结构既有利于电子和离子的传输,又能够有效抑制Co3O4在脱嵌锂过程中因体积变化引起的结构破坏.总体而言,合成的新型三元复合材料具有高的比容量以及良好的循环性能与倍率性能.     

一种二维多孔窗口型膦酸锆材料的合成及其对不同金属离子的吸附性能

合成了一种二维窗口型膦酸锆材料β-丙氨酸-N,N-双亚甲基膦酸锆(ZrNCP),采用X射线衍射仪、扫描电镜、透射电镜分析了合成产物的相组成和微观结构;利用N2吸脱附试验装置测定了合成产物对不同金属离子的吸附性能,考察了浓度、温度及pH对其吸附性能的影响.结果表明,合成产物内部存在大量分布均匀的微介孔,材料微观形貌为规整片状.随着金属离子半径的增大,ZrNCP对各种金属离子的平衡吸附量(mmol/g)呈逐渐减小趋势.     

Studies on the Thermodynamic and Kinetic Properties of the Reactions of Ti+ with Sulfur Transfer Reagent SCO Along the C═S Bond Activation Branch at 200–1200K

Theoretical studies on the thermodynamic and kinetic properties of the reactions of Ti⁺ with sulfur transfer reagent SCO via the C═S bond activation pathway have been carried on using DFT/B3LYP method, general statistical thermodynamics, and Eyring transition state theory with Wigner correction. The relevant reactions include reaction 1 ⁴ Ti⁺+¹SCO → ⁴ IM ₁ → ⁴ TS ₁ → ⁴ IM ₂ → ⁴ TiS⁺+ ¹ CO, and reaction 2 ⁴Ti⁺+¹SCO →⁴IM₁→ CP →²IM₂→²TiS⁺+¹CO in which the spin multiplicity changes from the quartet state to the doublet state in the crossing region. It is concluded that the increase of the temperature is favored to the reaction 1 process, since the equilibrium constants (K) rises from 0.566 × 10[P]-9 at 200 K to 0.109 × 10⁰ at 1200 K, and the reaction rate constant (k) from 0.222 × 10⁰ s[P]-1 at 200 K to 0.540 × 10 ¹¹ s[P]-1 at 1200 K. Moreover, reaction 1 is endothermic, and non-spontaneous in the way the entropy increases, while reaction 2 is exothermic and spontaneous in the way their entropy decreases. The reaction path 2 is the energetically favorable channel, and its thermodynamic data change not largely with the rise of temperature.     

Synthesis and electrochemical properties of a novel calix[4]arene derivative for facilitated transfer of alkali metal ions across water/1,2-dichloroethane micro-interface

The alkali metal ion transfers facilitated by a novel calix[4]arene derivative (OPEC) across the water/1,2-dichloroethane (1,2-DCE) micro-interface supported at the tip of a micropipette were presented. The well-defined voltammetric behaviours except Cs⁺ was obtained by cyclic voltammetry and differential pulse voltammetry. The bulk concentration of metal ions was much higher than that of OPEC in the performed measurements. The diffusion coefficient of OPEC in the 1,2-DCE phase was calculated as 5.18 ± 0.70 × 10^? 6 cm² s^? 1. On the basis of the changes of the half-wave transfer potentials, the logarithms of the association constants having 1:1 ionophore–ion complex stoichiometry for Li⁺, Na⁺, K⁺ and Rb⁺ in 1,2-DCE were determined as 4.80, 4.62, 4.98 and 5.32, respectively. The facilitated ion transfers were also evaluated by the Randles equivalent circuit used for ac-impedance data analysis.