蜂窝状C3N4/CoSe2/GA复合光催化剂的制备及CO2还原性能

以六水金氯化钴、 硒粉和尿素为前驱体, 通过水热法合成C₃N₄/CoSe₂纳米粒子, 再将其锚定在石墨烯气凝胶（Graphene aerogel, GA）表面, 制备蜂窝状C₃N₄/CoSe₂/GA光催化剂. 采用X射线衍射(XRD)、 X射线光电子能谱(XPS)、 扫描电子显微镜(SEM)、 透射电子显微镜(TEM)和紫外-可见漫反射光谱(UV-Vis DRS)等手段对材料的结构、 形貌和光学性能进行表征. 同时以氙灯作为模拟可见光光源, 通过CO₂光催化还原为CO考察所制备纳米材料的光催化活性. 结果表明, 在C₃N₄纳米片表面引入了CoSe₂和GA并制备出蜂窝状结构 C₃N₄/CoSe₂/GA催化剂, 通过GA, CoSe₂与C₃N₄耦合可以显著提高光吸收密度以及扩展光响应范围, 呈现了更低的荧光强度和最大的电子转移速率. 在同种光催化下, C₃N₄/CoSe₂/GA对CO₂还原催化效率最大, CO产量达到5.75 μmol·g^-1·h^-1, 并且重复使用性能良好.     

Synthesis, structural characterization and reactivity of the amino borane 1-(NPh2)-2-[B(C6F5)2]C6H4

The bright red title compound 1 was synthesized from (2-lithiophenyl)diphenylamine and bis(pentafluorophenyl)boron chloride. Its reactions with small acids like H₂O and HCl proceeded easily giving zwitterionic compounds. For 1 and its water adduct 2 the crystal structures were determined, the latter featuring an ammonium borate structure containing a short intramolecular hydrogen bond bridge. Treatment of 1 with Jutzi's acid, [H(OEt₂)₂][B(C₆F₅)₄], did not result in protonation of the nitrogen, but reaction of 1 with LiH in the presence of 12-crown-4, led to the isolation of the aminoborate [1-(Ph₂N)-2-{B(H)(C₆F₅)₂}C₆H₄][Li(12-crown-4)] (3). Borohydride 3 reacted with Jutzi's acid to regenerate 1 and liberate hydrogen.     

C5~C7烃类组分在Al2O3毛细管色谱柱上的分离及应用

详细研究了54种常见的C₅~C₇烃类组分在S型、KCl型和M型3种类型Al₂O₃毛细管色谱柱上的分离和定性,结果显示大部分C₅~C₇烃类组分在3种类型Al₂O₃毛细管色谱柱上的分离效果良好,但也存在一些组分分离不完全或共流出的现象,3种类型Al₂O₃毛细管色谱柱上的分离效果也存在一定的差异。共测定了15个C₅烃类组分,25个C₆烃类组分及14个C₇烃类组分在这3种类型Al₂O₃毛细管色谱柱上的线性程序升温保留指数,为C₅~C₇烃类组分在Al₂O₃毛细管色谱柱上的定性提供了依据。同时定量分析了某石化企业的裂解气样品中C₅~C₇烃类组分的含量。本研究拓展了Al₂O₃毛细管色谱柱的应用范围,可以为石化企业轻烃的分析提供参考。     

不同半导体体系中磷化镍光催化甲酸分解的助催化作用

研究了在不同的半导体体系(TiO₂, CdS和C₃N₄)中, Ni₂P光催化甲酸(HCOOH)分解制氢的助催化效应. 作为助催化剂, Ni₂P与3种半导体形成的复合光催化剂均表现出良好的HCOOH分解制氢活性. Ni₂P/TiO₂, Ni₂P/CdS, Ni₂P/C₃N₄ 3种光催化剂最优的产氢活性分别为41.69, 22.45和47.67 μmol·mg^-1·h^-1, 分别为纯TiO₂, CdS和C₃N₄的3.8倍、 10倍和210倍, 表明Ni₂P在光催化HCOOH分解制氢体系中具有普适性. 研究了光催化HCOOH分解制氢的机理, Ni₂P的加入使光生电子从半导体转移至Ni₂P, 提高了光生电子-空穴对的分离效率; Ni₂P还促进了活性物种·OH的生成, 提高了光催化HCOOH分解的产氢速率.     

Use of cerium oxide (CeO(2)) as a packing material for the chromatographic separation of C(60) and C(70) fullerenes

Cerium oxide (CeO₂) was tested as a packing material in liquid chromatography for the separation of C₆₀ and C₇₀ fullerenes. The separation of C₆₀ and C₇₀ fullerenes could be achieved within 20 min by using pure n-hexane as the mobile phase. Furthermore, some higher fullerenes could also be separated in less than 40 min. The peak area was reproducible to a large extent. The separation of fullerenes by liquid chromatography on CeO₂ is shown to be an effective method for their isolation in large amounts. The column efficiency of the CeO₂ column was compared with commercial silica gel and ODS columns. The main advantage of the CeO₂ column is its ability to separate large amounts of fullerenes (C₆₀ and C₇₀) in toluene.     

钼(Ⅵ)和钨(Ⅵ)的阴离子交换性能研究——草酸-盐酸体系

本文在草酸-盐酸体系中,研究钼、钨等元素在强碱性阴离子交换树脂ZerolitFF上的阴离子交换行为,并确定其分离的最佳条件。用高仅2厘米,直径0.9厘米的交换柱可分离大量钨等元素中的微量钼;其分离比率高达1×10⁴:1。应用于试剂级钨酸钠中钼的分离,结果满意。此外,还确定在该体系中,钼与树脂相进行交换的主要形式为MoO₂(C₂O₄)₂^2-。     

Synergic Extraction of Uranium Thiocyanate by the Ternary System of ABC Species Composed of PMBP-TBP-(C6H5)4AsCI

The synergic extraction of uranyl thiocyanate with binary system of 1-phenyl-3-methy1~4-benzoylpyrazolone-5 (PMBP)and tributyl phosphate(TBP)or tetraphenylarsonium chloride [(C6H5)4AsCl] and ternary system of PMBP-TBP-(C6H5 )4AsCl was studied.There was an obvious synergic effect of uranium (VI)from thiocyanate medium in binary and ternary systems.The formation of a ternary extracted complex,(C6H5)4AsUO2.(NCS)A2 TBP,was confirmed by the slope method.A method was first proposed for the calculation of the equilibrium constant of ternary synergic reaction.     

Isobutene homo- and isobutene-isoprene copolymerization initiated by protic initiators associated with a series of novel, weakly coordinating counteranions

The highly electrophilic borane B(C₆F₅)₃ reacts with a variety of carboxylic acids RCO₂H to form 1:1 and 1:2 adducts [RCO₂H][B(C₆F₅)₃] and [RCO₂H][B(C₆F₅)₃]₂. These adducts exhibit enhanced acidities, and the 1:2 adduct of n-decanoic (stearic) acid in particular is an excellent initiator for the carbocationic polymerization of isobutene and copolymerization of isobutene with isoprene in methylene chloride and methyl chloride. High conversions to high molecular weight polyisobutene and isobutene-isoprene copolymers are obtained at unusually high temperatures, consistent with the anion [n-C₁₇H₃₅CO₂ BC₆F₅)_{3 2}]⁻ being very weakly coordinating. Interestingly, the system also exhibits a surprising, as yet not understood, dependence of polymer molecular weights on the nature of R in methyl chloride.     

Fourier transform IR spectrum and photoreactivity of the C3O2:HCl complex isolated in solid argon

IR spectroscopy was coupled with the matrix isolation technique to study the molecular complex formed between C₃O₂ and HCl and its photodissociation. The vibrational frequencies of the complex were compared with those of HCl and C₃O₂ monomers. For C₃O₂, a bent structure was characterized in the solid environment.

The vibrational frequencies were calculated in the 4000–400 cm⁻¹ range using an ab initio method at the MP2/6-31G** level for the most stable complex; these frequencies describe the hydrogen interaction with the central carbon atom of C₃O₂ (T complex). The measured shifts between the vibrational mode frequencies of the complex and monomers were in good agreement with the calculated values.

Broad-band UV irradiation ( > 230 nm) of the T complex leads preferentially to ketene chloride and carbon monoxide. Ketene chloride formation can be explained by the reaction between HCl and the carbene C₂O, which results from photo-dissociation at the C=CO bond of C₃O₂.     

Determination of C4-C14 carboxylic acids by capillary zone electrophoresis. Application to the identification of diamide degradation products and partitioning studies.

Capillary zone electrophoresis (CZE) was investigated for the determination of linear saturated carboxylic acid homologues ranging from C₄ to C₁₄. Separation conditions were optimised to overcome the problems of decreasing solubility and decreasing selectivity between successive homologues with increasing chain length. Separations were performed at 20°C, using a 20 kV separation voltage and a pH 8 electrolyte containing 30% methanol. A suitable chromophore (4-aminobenzoate) was added to ensure indirect UV detection of the analytes. Calibration curves and repeatability were established. Minimum detectable concentrations of 3·10⁻⁶ mol l⁻¹ were achieved. Resolution between successive homologues was better than 2. The electrophoretic mobility of each homologue (n=7–14) was assessed and a quasi-linear relationship between the mobility value and 1/n was observed. The quantitative analysis of a diamide degradation solution was performed and compared to potentiometric results. The CZE method was also applied to the determination of C₇–C₁₄ partitioning between an organic medium containing tributylphosphate in n-dodecane and different basic solutions. Their behaviour was established according to the chain length and the pH of the aqueous phase. For C₁₀–C₁₄ compounds, results were validated by comparison with gas chromatographic analysis of the organic phases.     

皂荚素的表面活性及其二元体系的热力学研究

通过表面张力的测定研究了皂荚素(GS)的表面活性及其热力学性质随温度的变化.测定了皂荚素分别与十二烷基磺酸钠、十二烷基聚氧乙烯醚硫酸钠、全氟辛酸钠、十二烷基脂肪醇聚氧乙烯(9)醚、辛基酚聚氧乙烯(10)醚及十六烷基三甲基溴化铵等复配的表面张力-浓度对数关系(γ～lgc)曲线,并用二维晶格模型及正规溶液理论计算了含皂荚素的二元表面活性剂溶液表面吸附层的组成、分子相互作用参数及分子交换能.结果表明,皂荚素主要呈现非离子表面活性剂的性质,与阳离子表面活性剂复配呈微弱的离子性.复配后分子交换能均小于零,复配增效.增效顺序为GS/阳离子>GS/非离子>GS/阴离子(表面活性剂复配体系).     

Two-dimensional cobalt metal-organic frameworks for efficient C3H6/CH4 and C3H8/CH4 hydrocarbon separation

A Co-based two-dimensional (2D) microporous metal-organic frameworks (UPC-32) with narrow distance between layers and layers (3.8 Å) exhibits high selectivity of C₃H₆/CH₄ (31.46) and C₃H₈/CH₄ (28.04) at 298 K and 1 bar. It is the first 2D Co-MOF that showed selective separation of C3 hydrocarbon from CH₄.     

Microporous Zinc Formate for Efficient Separation of Acetylene over Carbon Dioxide

Separation of acetylene(C₂H₂) from carbon dioxide(CO₂) by adsorbents is very challenging owing to their high similarity on molecular shape and dimension. Exploring inexpensive and easily available porous materials is of importance to facilitate the practical implementation of the challenging but energy-efficient separation. Herein, we utilize an easily available porous material[Zn₃(HCOO)₆] for the selective separation of C₂H₂ over CO₂. Because of the pore confinement in[Zn₃(HCOO)₆](pore size of 0.47 nm) and accessible oxygen sites for preferential binding of C₂H₂, this material exhibits high low-pressure uptake for C₂H₂(63 cm³/cm³ at 10 kPa and 298 K) and high C₂H₂/CO₂ selectivity(7.4 under ambient conditions) that is comparable to those of out-performing porous materials. The efficient separation of[Zn₃(HCOO)₆] for C₂H₂/CO₂ mixture has also been confirmed by the breakthrough experiments.     

The evaluation of singlet-triplet separations for [W2(μ-H)(μ-Cl)Cl4(μ-dppm)2] and [W2(μ-H)2 (μ-O2CC6H5)2(P(C6H5)3)2] based on P NMR and crystallographic data

The singlet-triplet separations for the edge-sharing bioctahedral (ESBO) complex W₂(μ-H)(μ-Cl)(Cl₄(μ-dppm)₂ · (THF)₃ (II) has been studied by ³¹P NMR spectroscopy. The structural characterization of [W₂(μ-H)₂(μ-O₂CC₆H₅)₂Cl₂(P(C₆H₅)₃)₂] (I) by single-crystal X-ray crystallography has allowed the comparison of the energy of the HOMOLUMO separation determined using the Fenske-Hall method for a series of ESBO complexes with two hydride bridging atoms, two chloride bridging atoms and the mixed case with a chloride and hydride bridging atom. The complex representing the mixed case, [W₂(μ-H)(μ-Cl)Cl₄(μ-dppm)₂ · (THF)₃] (II), has been synthesized and the value of −2J determined from variable-temperature ³¹P NMR spectroscopy.     

高效液相色谱-串联质谱法检测三苯乙烯基苯酚聚氧乙烯醚

建立了高效液相色谱-串联质谱检测三苯乙烯基苯酚聚氧乙烯醚(tristyrylphenol ethoxylates,TSPn EO)的分析方法,并对TSPn EO在反相色谱柱(XBridge C_(18),150 mm×2.1 mm,3.5μm)、亲水相互作用色谱柱(XBridge HILIC,150 m m×2.1 m m,3.5μm)、氨基色谱柱(XBridge Amide,150 m m×2.1 m m,3.5μm)、伪反相色谱柱(C18柱(XBridge C_(18),50 mm×2.1 mm,5μm)与硅胶柱(Nova-Pak Silica,150 mm×2.1 mm,4μm)串联)4种不同液相色谱分离模式下的分离效果进行了研究。实验比较了5 mmol/L乙酸铵水-乙腈、0.1%(v/v)甲酸水-乙腈、水-乙腈和水-甲醇4种流动相组成及3种梯度洗脱条件对分离效果和灵敏度的影响。探讨了TSPnEO在电喷雾离子(ESI)源内的离子化特征,结果表明,在ESI正离子模式下,TSPnEO在离子源内形成[M+NH4]+离子,其聚合度的分布特征符合泊松分布。利用伪反相色谱柱,水-乙腈作为流动相,实现了不同聚合度(n=5~18)TSPnEO的分离。     

Photocatalytic Hydrogen Evolution Performance for Hydroxyl-rich Porous Carbon Nitride

Metal-free photocatalyst C₃N₄ has been well investigated, while how to create hydroxyl-rich porous C₃N₄ remains a great challenge. Herein, we report a facile approach to address this issue by developing a novel two-step process:(i) precursor achieved via freeze-drying the mixture of urea, thiourea and NH₄Cl; (ii) subsequent thermal polydensation of the precursor. Systematic sample characterization demonstrated the formation of C₃N₄ featured by unique hydroxyl-rich porous structure with an extended tri-s-triazine unit. When applied as photocatalyst for water splitting under UV-Vis light irradiation, the sample displays a high hydrogen evolution rate of 243.4 μmol·g^-1·h^-1, about 4 times higher than that of C₃N₄ prepared by conventional method. Such a performance enhancement could be due to the porous structure and surface hydroxyl-rich functional groups that promote multiple-times reflection and light absorption, increase the active site numbers, and improve carrier transfer/separation efficiency.     

三种六氯铈(Ⅳ)酸有机盐的研究

合成了2,6-二甲基-γ-吡喃酮、咪唑和吡啶铈(Ⅳ)的氯化物,化学式为(C₇H₈O₂H)₂CeCl₆、(C₃H₄N₂H)₂CeCl₆和(C₄H₉NH)₄CeCl₈.采用差热、热重分析法比较了上述三种化合物的热稳定性,并配合以电导、红外、紫外光谱等手段进行了结构分析.     

C_9H_(10)O_2-0.5ZnCl_2/Al_2O_3的制备及其氧化脱硫性能

通过将C_9H_(10)O_2-0.5ZnCl_2双酸型低共熔溶剂固载到Al_2O_3上制备了C_9H_(10)O_2-0.5ZnCl_2/Al_2O_3催化剂。该催化剂采用XRD、FT-IR、SEM、EDS、N_2吸附-脱附技术进行了分析。以C_9H_(10)O_2-0.5ZnCl_2/Al_2O_3为催化剂,过氧化氢为氧化剂研究模拟油中芳香族硫化物的脱除性能。考察反应参数如温度、催化剂加入量、O/S物质的量比、硫化物类型等对催化剂脱硫活性的影响。实验结果表明,在模拟油为5 mL、催化剂量为0.2 g、O/S比为8、反应温度为60℃、反应时间为180 min的条件下,模拟油中二苯并噻吩(DBT)脱硫率为99.2%。此外,在模拟油氧化脱硫中催化剂循环使用六次,其氧化脱硫活性略有降低。研究了C_9H_(10)O_2-0.5ZnCl_2/Al_2O_3催化氧化脱硫的反应机理。     

1-烷基-3-甲基咪唑氯化物焓变的热重分析

The structures of ionic liquids (ILs) based on 1-alkyl-3-methylimidazolium chloride [C_nmim]Cl (n = 2, 4, 6), (1-ethyl-3-methylimidazolium chloride [C₂mim]Cl, 1-butyl-3-methylimidazolium chloride [C₄mim]Cl, and 1-hexyl-3-methylimidazolium chloride [C₆mim]Cl) were elucidated by ¹H NMR and ¹³C NMR experiments. The vaporization characteristics of these ILs were studied by thermogravimetric analysis. Dynamic and isothermal thermogravimetric experiments were conducted in this study. The purpose of the dynamic experiments was to determine the initial decomposition temperature of the experimental sample and the temperature range for the isothermal thermogravimetric experiments. The purpose of the isothermal experiments was to record the mass dependence of the sample on time in the experimental temperature range. The Langmuir equation and Clausius-Clapeyron equation were used to fit the experimental data and obtain the vaporization enthalpies of these ILs at the average temperature within the experimental temperature range. However, in order to expand the applicability of the estimated values and to compare them with the literature data, the vaporization enthalpy ΔH_vap(T_av) measured at the average temperature was converted into vaporization enthalpy ΔH_vap(298) at ambient temperature. The difference between the heat capacities of the ILs in the gaseous and liquid states at constant pressure, Δ_l^gC_pm^ө proposed by Verevkin, was used in this conversion process. The experimental data for substance density and surface tension at other temperatures were obtained by referring to the literature. In addition, the data for density and surface tension at T = 298.15 K were obtained by applying the extrapolation method to the literature values for other temperatures. The vaporization enthalpy of the 1-octyl-3-methylimidazolium chloride IL [C₈mim]Cl was estimated by using the new vaporization model we had proposed in our previous work and compared with the reference value. The estimated value for [C₈mim]Cl was on the same order of magnitude as the reference value. We compared the vaporization enthalpies in the present study with those for the carboxylic acid imidazolium and amino acid imidazolium ILs ([C_nmim]Pro (n = 2-6) and [C_nmim]Thr (n = 2-6), respectively in our previous work. The results revealed that a change in the anion type affects the vaporization enthalpy of the ILs in the order amino acid imidazolium > carboxylic acid imidazolium > halogen imidazolium, when the cation is the same. Considering the structural differences between the three kinds of ILs, the abovementioned order may be related to the intermolecular hydrogen bonds. There were no intermolecular hydrogen bonds in the [C_nmim]Cl (n = 2, 4, 6) ILs studied here. Therefore, the vaporization enthalpy of [C_nmim]Cl (n = 2, 4, 6) was the lowest among the three kinds of ILs considered.     

C59(C6H4OCH3)N的结构、光谱和二阶非线性光学性质的理论研究

用INDO系列方法对由(C₅₉N)₂和苯甲醚合成的衍生物C₅₉(C₆H₄OCH₃)N进行了理论研究,得到了分子的稳定构型.结果表明,C₅₉(C₆H₄OCH₃)N具有C_s对称性.以优化构型为基础讨论了分子的UV-Vis光谱、NMR谱线数,结果与实验符合得很好.本文还计算了C₅₉(C₆H₄OCH₃)N的二阶非线性光学系数β_μ,结果表明这种物质具有较大的二阶非线性光学系数.