基于对苯二甲酸配体的含二维铅无机层的三维无机-有机杂化材料的合成及晶体结构(英文)

以对苯二甲酸作为配体,利用水热法合成了含二维(2D)铅无机层的三维(3D)无机-有机杂化材料[Pb2Cl(1,4-BDC)1.5]n(1);利用红外光谱、电感耦合等离子体原子发射光谱、X-射线衍射表征了产物的结构,利用热重分析测定了其热稳定性.结果表明,[Pb2Cl(1,4-BDC)1.5]n属于单斜晶系,P21/c空间群,其晶格参数为:a=0.599 000(10)nm,b=1.185 29(2)nm,c=1.847 37(3)nm,β=91.778 0(10)°,V=1.310 98(4)nm3,Z=4,R1=0.032 0,wR2=0.089 4,Rint=0.043 6.就化合物1的分子结构而言,由Pb—X—Pb(X=O或Cl)链接形成的2D无机层通过对苯二甲酸配体连接,构筑成具有3D骨架的无机-有机杂化材料.     

Enhanced photocatalytic activity of Ni doped TiO2 nanowire–nanoparticle hetero–structured films prepared by hydrothermal and sol–gel methods

TiO₂ nanowire-nanoparticle hetero-structured films were prepared via a sol–gel method and coated on glass substrates by dipping method for photocatalytic activity. In this study 0, 1, 3, and 5 mol% of Ni doped were studied. One-dimensional TiO₂ nanowires (NWs) were prepared by hydrothermal treatment with TiO₂ nanoparticles (NPs) which are commercially available. XRD, FESEM, DRS, and XPS were used to characterize the prepared nanowire-nanoparticle hetero-structures films. 3%Ni doped TiO₂ hetero-structured film (TNi3) had the highest photocatalytic activity on the degradation of methylene blue (MB). TNi3 films provided about 4.3 times of degradation rate compared to undoped TiO₂ (T). It revealed that TNi3 film resulted in shifting the absorption wavelength towards narrowing the energy band gap and small crystallite size. Therefore, the TNi3 film exhibited a photocatalytic activity on the degradation of MB under visible light irradiation greater than undoped film.     

香菇生物质基氮掺杂微孔碳材料的制备及其在超级电容器中的应用

采用简易浸泡法和一步碳化/活化法制备香菇生物质基氮掺杂微孔碳材料(NMCs),利用扫描电子显微镜(SEM)、透射电子显微镜(SEM)、X射线衍射(XRD)和X射线光电子能谱(XPS)对材料的结构形貌进行表征,并研究了其超级电容特性。测试结果表明,NMCs的微孔比表面积高达1 594 m~2·g~(-1),且拥有更高数量的含氮官能团,其吡啶型含氮官能团比例也有所提高,展现出优异的超级电容特性。在0.5 A·g~(-1)的电流密度下,其比容量高达325 F·g~(-1),当电流密度上升到20 A·g~(-1)时,其比电容仍然高达180 F·g~(-1),表现出优异的倍率性能;同时,在5 A·g~(-1)的电流密度下,电极经历5 000次充放电循环后具有97.7%的比容量保持率,展现出优异的循环稳定性。这主要归因于NMCs超高的微孔比表面积和丰富的含氮官能团。     

Preparation of MnO2 Loaded Hydrothermal Carbon-coated Electrospun PAN Fiber Membranes for Highly Efficient Adsorption and Separation of Cationic Dye

Hydrothermal carbonaceous materials and MnO₂ have been proved to be promising adsorbents to remove organic dyes from wastewater. In this study, flexible MnO₂ loaded hydrothermal carbon-coated electrospun poly-acrylonitrile(AC/MnO₂/PAN) fiber membranes were fabricated by a facile one-step hydrothermal method and activated by NaOH solution. The composite fibers exhibited large adsorption capacity toward cationic dyes and excellent mechanical properties. The adsorption performance can be fitted well with pseudo-second-order model and Langmuir isotherm model. The maximum adsorption for methylene blue(MB), methyl violet(MV) and malachite green(MG) are 1173.27,1106.31 and 1129.89 mg/g, respectively, according to Langmuir fitting. The AC/MnO₂/PAN fiber membrane also showed satisfactory performances for selective adsorption and recyclability. In addition, based on selective adsorption, the AC/MnO₂/PAN fiber membranes that are repulsive to the anionic dye methyl orange(MO) can separate the MB/MO mixture solution by dynamic filtration. Thus, this work not only provides a facile strategy to fabricate large capacity adsorbents, but also demonstrates the potential applications in the dye wastewater treatment field.     

碱性膜燃料电池阳极碳酸化模型研究

碱性聚电解质燃料电池（APEFC）近年来取得了可观的进展,但是在使用空气作为氧化剂工作时仍然面临着性能损失. 文献中已有多个理论试图解释性能损失的来源,但是缺乏定量化的分析. 本文根据实验发现和热力学及阳极反应的动力学分析,提出了分层的阳极碳酸化模型和方程组.模型的定量化模拟结果进一步和实验结果进行验证,提出了电池性能损失的可能原因.     

A Promising Electrochemical Platform for Dopamine and Uric Acid Detection Based on a Polyaniline/Iron Oxide-Tin Oxide/Reduced Graphene Oxide Ternary Composite

A ternary polyaniline/Fe₂O₃-SnO₂/reduced graphene oxide (PFSG) nanocomposite was prepared using a simple two-step hydrothermal treatment. The composite was applied as a glassy carbon electrode modifier (GCE) to enhance dopamine (DA) and uric acid (UA) detection. The ternary PFSG composite was compared with its binary precursor Fe₂O₃-SnO₂/reduced graphene oxide (FSG). The influence of the modified GCE electrodes on their performance as a sensing platform was determined. GCE/PFSG showed better sensing parameters than GCE/FSG due to the introduction of polyaniline (PANI), increasing the electrocatalytic properties of the electrode towards the detected analytes. GCE/PFSG enabled the detection of low concentrations of DA (0.076 µM) and UA (1.6 µM). The peak potential separation between DA and UA was very good (180 mV). Moreover, the DA oxidation peak was unaffected even if the concentration of UA was ten times higher. The fabricated sensor showed excellent performance in the simultaneous detection with DA and UA limits of detection: LOD_DA = 0.15 µM and LOD_UA = 6.4 µM, and outstanding long-term stability towards DA and UA, holding 100% and 90% of their initial signals respectively, after one month of use.     

A Factorial Design Approach for Hydrothermal Synthesis of Phase‐Pure AgInO2: A Parametric Optimization Study

Owing to a wide range of industrial applications and fundamental importance, delafossite compounds have gathered tremendous interest in research community. In this study, the formation of hexagonal nanoplates of AgInO₂ mainly dominated by (00l) facets with no metallic Ag impurity, reported using a facile hydrothermal route at 180 °C using KOH as mineralizer by adopting a factorial design approach. Rietveld analysis of the powder XRD pattern and SAED confirms the rhombohedral system of AgInO₂. FE‐SEM image shows a uniform hexagonal plate‐like morphology with an average width of about 300 nm and thickness of 70 nm. XPS and EDX analysis confirm potassium ion free AgInO₂. A specific surface area of about 48.5 m² g^?1 is arrived from N₂ adsorption studies. Temperature‐dependent AC impedance measurements revealed an activation energy of 0.24 eV/f.u. Further, TG‐DTA studies found that the compound is stable in air up to 595 °C.     

Single‐Mode Microwave Heating‐Induced Concurrent Out‐of‐Plane Twin Growth Suppression and In‐Plane Epitaxial Growth Promotion of b‐Oriented MFI Film under Mild Reaction Conditions

In this study, single‐mode microwave heating was applied in epitaxial growth of b‐oriented MFI seed monolayer prepared by facile manual assembly, resulting in the formation of well‐intergrown and highly b‐oriented MFI film with few twins. It exhibited a precise molecular sieving property at a reaction temperature no higher than 100 °C within 2 hours, therefore making it possible for easy operation in an open environment. The capability for concurrent suppression of undesired out‐of‐plane twin growth and promotion of in‐plane epitaxial growth rate under mild reaction conditions was attributed to the obvious superiority of single‐mode microwave heating in comparison with conventional multi‐mode microwave heating in aspects of microwave field uniformity and intensity. Our research indicated that the single‐mode microwave heating technique could potentially be a useful tool for improving the microstructure and therefore the performance of diverse zeolite films.     

高酸位多级孔超稳Y型沸石的制备及催化性能

以表面活性剂十六烷基三甲基溴化铵(CTABr)为模板剂,在水热体系对水蒸气处理后的超稳Y型(USY)沸石进行晶化处理,获得高酸量和高水热稳定性的USY-c-w样品。利用X射线衍射、扫描电子显微镜、透射电子显微镜、固态核磁共振、N₂吸附-脱附、NH₃-程序升温脱附、傅里叶变换红外光谱及吡啶红外对所制备催化剂的物化性质进行详细表征。选用1,3,5-三异丙苯(TIPB)催化裂化作为探针反应,研究制备的催化剂的催化性能,并与工业USY沸石进行对比。结果表明,再次水热晶化后,样品的硅铝骨架局部重构,非骨架铝重新进入沸石骨架,合成样品的硅铝比(n_Si/n_Al)由10降至3.0;再晶化后的USY沸石,不仅具有丰富的介孔结构,并且具有更多的弱酸和中强酸位点。在TIPB裂解反应中,再晶化后的USY沸石表现出比原样品更优异的催化性能。     

水热法制备纳米TiO2及其在水相介质中分散性的研究

以硫酸法钛白粉生产工艺的中间体偏钛酸为原料,采用水热法制备了纳米TiO2粉体。研究了磷酸、硫酸、反应温度及反应时间对TiO2粉体的晶型、粒径及形貌的影响,考察了其在水相介质中的分散性。并借助XRD、SEM、动态激光粒度分析仪和动电位及静态激光粒度分析仪对其进行了表征。