The electrochemical reduction reaction of dissolved oxygen on Q235 carbon steel in alkaline solution containing chloride ions

Cyclic voltammetry, electrochemical impedance spectroscopy, and rotating disk electrode voltammetry have been used to study the effect of chloride ions on the dissolved oxygen reduction reaction (ORR) on Q235 carbon steel electrode in a 0.02 M calcium hydroxide (Ca(OH)₂) solutions imitating the liquid phase in concrete pores. The results indicate that the cathodic process on Q235 carbon steel electrode in oxygen-saturated 0.02 M Ca(OH)₂ with different concentrations of chloride ions contain three reactions except hydrogen evolution: dissolved oxygen reduction, the reduction of Fe(III) to Fe(II), and then the reduction of Fe(II) to Fe. The peak potential of ORR shifts to the positive direction as the chloride ion concentration increases. The oxygen molecule adsorption can be inhibited by the chloride ion adsorption, and the rate of ORR decreases as the concentration of chloride ions increases. The mechanism of ORR is changed from 2e⁻ and 4e⁻ reactions, occurring simultaneously, to quietly 4e⁻ reaction with the increasing chloride ion concentration.     

碱金属盐催化1,2,4-三唑与α,β-不饱和酮及二酰亚胺的氮杂Michael反应

发展了一种高效的碱金属盐催化1,2,4-三唑与α,β-不饱和酮及α,β-不饱和二酰亚胺的氮杂Michael加成反应的新方法,以中等到优异的产率得到目标产物.该方法原料易得,底物普适性好,反应条件温和,易实现克级规模的制备.产物容易转化为相应的γ-氨基醇.     

Surfacial carbonized palygorskite as support for high-performance Pt-based electrocatalysts

Pt nanoparticles deposited on a low-cost, surfacial, carbonized palygorskite (Pt/C-PLS) prepared by carbonizing sucrose were evaluated as a methanol oxidation catalyst for direct methanol fuel cells. Transmission electron microscopy and Fourier transfrom infrared spectrophotometry analyses revealed that carbon was formed on the surface of PLS and that free silica presented in the C-PLS support. The catalytic activity of methanol oxidation of Pt/C-PLS was higher than that of Pt/C, and the former catalyst had better CO tolerance.     

不同类型卟啉自组装膜的制备及表征

制备了不同类型的巯基卟啉自组装膜,借助多种表征技术（紫外可见光谱、电化学和X射线光电子能谱）研究了不同类型卟啉自组装膜的结构特点;研究结果表明,卟啉分子中巯基取代基数目的不同（-[SH]n-,n=1,4）,导致了卟啉环在自组装膜表面的构型不同,从而表现出不同巯基卟啉自组装膜性能的差异。 在此基础上,提出了不同巯基卟啉自组装膜的结构模型。     

Bio-inspired fabrication of well-oriented ZnO nanorod arrays film and its superhydrophobicity and superhydrophilicity

A highly oriented ZnO nanorod array film was fabricated on glass substrate by combinations of Sol–Gel and hydrothermal. The film exhibits perfect superhydrophobicity with a contact angle of 155° and a glide angle of 4° after being surface modified by fluoroalkylsilane, which is similar with wings’ property and structures of large yellow spots mosquitoes. Interestingly, the ZnO nanorods film were converted from superhydrophobicity into superhydrophilicity under ultraviolet light for 2 h due to the decomposition of fluoroalkyl chain of fluoroalkylsilane and the photosensitivity of ZnO surface. The transition mechanisms of wettability are discussed on the basis of correlated theories.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Preparation of superhydrophobic composite paper mulching film

To study the influence of different concentrations of zinc oxide (ZnO)/silicon dioxide (SiO₂) composite coating on hydrophobic property and mechanical stability of paper mulch film, three kinds of ZnO/SiO₂ composite coating paper mulch films (2%, 4%, 6%) with different coating substance contents were prepared by brush coating method. Through particle size analysis, contact angle, rolling angle and mechanical stability test, combined with scanning electron microscope, three-dimensional morphology and roughness measuring instrument, the optimal concentration of ZnO/SiO₂ composite coated paper mulch film was screened out. Through acid-base salt corrosion test, silver mirror reaction and surface self-cleaning, the optimal concentration of composite coated paper mulch film was compared with the original paper mulch film to prove its excellent chemical stability and hydrophobicity. The results show that the paper mulch film with 4% coating material has excellent hydrophobicity and mechanical stability, can effectively reduce the surface roughness of paper mulch film, and has remarkable effects in resisting acid, alkali and salt and self-cleaning.     

高分子填料在生物法处理废水中的应用进展

对生物法处理废水用的高分子填料进行了综述。首先,从无机高分子填料、有机高分子填料两方面介绍了其应用特点及对废水中有机物的作用机理和去除效果;其次,介绍了新型生物填料,主要从生物亲和亲水磁性填料和酶促生物填料两方面介绍其在废水处理中的应用。     

卟啉类化合物分子光电器件研究进展

分子电子器件是未来分子电路的微电子元件,已成为有机功能纳米材料研究的热点。 卟啉类化合物的π共轭体系表现出的独特光电性能和良好的热稳定性,使其作为光电器件、模拟生物酶、分子识别和传感材料在材料化学、医学、生物化学和分析化学等领域展现出良好的应用前景,由于卟啉分子平面结构的易修饰性,常用卟啉化合物组装单元来构建功能化的卟啉光电器件。 本文综述了卟啉类化合物的特点及其在光电器件中的应用进展。