纳米镍钴铁氧体空心微球的制备与性能

以乙二醇为溶剂,氯化铁、氯化钴、氯化镍和醋酸铵为反应试剂,采用溶剂热法制备纳米Ni_xCo_1-xFe₂O₄(x=0、0.3、0.5、0.7、1)铁氧体空心微球,研究镍含量对铁氧体空心球的磁性与吸波性能的影响。借助X-射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、振动样品磁强计(VSM)和网络分析仪对试样的物相组成、微观形貌和电磁特性进行表征。结果表明制备的镍钴铁氧体为尖晶石结构,且形貌为空心球,粒径在200 nm左右。当x=0时,镍钴铁氧体空心球饱和磁化强度最大为81.7 emu·g^-1,反射损耗在1 658.8 MHz有最小值为-16.9 dB。     

Br-掺杂Bi2WO6的水热法合成及其可见光催化性能

以Bi（NO₃）₃·5H₂O和Na₂WO₄·2H₂O为主要原料,采用水热法合成了纯相Bi₂WO₆,并对其进行非金属离子Br^-掺杂改性。采用XRD、SEM、TEM、XPS、Raman、PL和DRS研究了Br^-掺杂对Bi₂WO₆的物相结构、形貌和可见光催化性能的影响。结果表明,Br^-掺杂可有效提高Bi₂WO₆的可见光催化性能,当掺杂量（物质的量百分数）为8%时,溴掺杂Bi₂WO₆的光催化性能最好,可见光照射40 min后,可降解96.73%的罗丹明-B,与未掺杂Bi₂WO₆相比,其降解率提高了36.32%。     

由四核Fe(Ⅱ)金属簇和三缺位Keggin型磷钨酸盐构筑的夹心型多金属氧酸盐(英文)

利用水热法合成了由四核FeⅡ簇和三缺位Keggin型磷钨酸盐共同构筑而成的夹心型多金属氧酸盐(H2dien)4H2[Fe4(H2O)2(α-B-PW9O34)2]·8H2O(1)(dien=二乙烯三胺);采用红外光谱、X-射线单晶衍射定性表征了产物的结构,利用元素分析测定了其组成.结果表明,化合物1属于三斜晶系,P-1空间群.其多阴离子[Fe4(H2O)2(α-B-PW9O34)2]10-由两个[α-B-PW9O34]9-单元通过Fe4O14(H2O)2簇连接而成;Fe2+离子采用六配位的八面体几何构型.同时,质子化的H2dien2+充当抗衡阳离子,经氢键与杂多阴离子[Fe4(H2O)2(α-BPW9O34)2]10-相互作用形成三维结构.     

Preparation of Li2SnO3 and its application in lithium‐ion batteries

Tin‐based oxide Li₂SnO₃ has been synthesized by a hydrothermal route as negative material for lithium‐ion batteries. The microstructure and electrochemical properties of the as‐synthesized materials were investigated by some characterizations means and electrochemical measurements. The as‐synthesized Li₂SnO₃ is a porous rod, which is composed of many uniform and regular nano‐flakes with a size of 50–60 nm. Li₂SnO₃ also displays an electrochemical performance with high capacity and good cycling stability (510.2 mAh g^?1 after 50 cycles at a current density of 60 mA g^?1 between 0.0 V and 2.0 V verusus Li/Li⁺). Copyright © 2013 John Wiley & Sons, Ltd.     

A Direct and Rapid Route to Synthesize Pd/Si‐MCM‐41 at Room Temperature

The pure silica mesoporous molecular sieve MCM‐41 was synthesized under hydrothermal conditions. Pd/Si‐MCM‐41 was prepared by the incipient wetness impregnation of pure silica MCM‐41 with mixed solution of PdCl₂, ethanol and CH₂Cl₂. The samples were characterized by x‐ray diffraction (XRD), transmission electron microscopy (TEM), and nitrogen adsorption–desorption isotherms at 77 K. The XRD and TEM results reveal that Pd is actually anchored inside the pores of Si‐MCM‐41 and the Si‐MCM‐41 structure is clearly maintained after impregnation.     

Bismuth Tri‐ and Tetraarylcarboxylates: Crystal Structures,In Situ X‐ray Diffraction,Intermediates and Luminescence

A systematic investigation of the systems Bi³⁺/carboxylic acid/HNO₃ for the tri‐ and tetracarboxylic acids pyromellitic acid (H₄Pyr), trimellitic acid (H₃Tri) and trimesic acid (H₃BTC) acid led to the discovery of five new bismuth carboxylates. Structural characterisation allowed the influence of the linker geometry and the Bi³⁺:linker molar ratio in the starting solution on the crystal structure to be determined. The crystallisation of three selected compounds was investigated by in situ energy‐dispersive X‐ray diffraction. Three new crystalline intermediates were observed within minutes, and two of them could be isolated by quenching of the reaction mixture. Their crystal structures were determined from laboratory and synchrotron X‐ray powder diffraction data and allowed a possible reaction pathway to be established. In depth characterisation of the luminescence properties of the three bismuth pyromellate compounds was carried out. Fluorescence and phosphorescence could be assigned to (mainly) ligand‐ and metal‐based transitions. The polymorphs of Bi(HPyr) exhibit different luminescence properties, although their structures are very similar. Surprisingly, doping of the three host structures with Eu³⁺ and Tb³⁺ ions was only successful for one of the polymorphs.     

Synthesis and Morphology Control of AM‐6 Nanofibers with Tailored ‐V‐O‐V‐ Intermediates

Microporous vanadosilicates with octahedral VO₆ and tetrahedral SiO₄ units, better known as AM‐6, have been hydrothermally synthesized with different morphologies by controlling the Na/K molar ratio of the initial gel mixtures. The morphology of the AM‐6 materials changed from bulky cube to nanofiber aggregates as the Na/K molar ratio decreased from 1.9 to 0.2. Raman spectroscopy revealed that the VO₃^? intermediate species plays an important role in the formation of the nanofiber morphology. The orientation of ‐V‐O‐V‐ chains in nanofiber aggregates was examined by confocal polarized micro‐Raman spectroscopy. It was found that these aggregates are assemblies of short ‐V‐O‐V‐ chains perpendicular to the axis of nanofibers. The obtained AM‐6 nanofibers greatly increase the exposed proportion of V? O terminals, and thus improve the catalytic performance.     

硫/水热碳球复合材料的制备及对锂硫电池倍率性能的影响

在锂硫电池正极材料的研究中,碳材料可以有效改善电池倍率及循环性能.为了提高锂硫电池的高倍率放电性能,通过水热合成的方法,制备了由非均匀粒径碳球组成的碳材料.与硫热合成后,硫均匀分布在碳材料表面及周围,复合材料含硫量为52wt%.0.2C放电电流下,首次放电比容量为1174mAh·g^-1,100次循环后放电比容量为788mAh·g^-1.在4C的放电电流下,放电比容量稳定维持在600mAh·g^-1,循环过程中,库伦效率高于90%.该碳材料有良好的导电网络,且制备方便,成本低廉,对于穿梭效应和放电过程中的膨胀效应有一定的抑制作用,是一种优秀的正极材料.     

由草酸及双咪唑基配体构筑的二维锰(Ⅱ)配位聚合物的水热合成及晶体结构

通过水热法合成了一个新的金属-有机配位聚合物[Mn(C2O4)(bimb)]n.0.25nH2O(H2C2O4=草酸,bimb=1,4-双(咪唑基-1-基)丁烷)。并对其进行了元素分析、红外光谱、紫外光谱、热重和X-射线单晶衍射测定。该配合物属于三斜晶系,P1空间群。在晶体结构中,锰原子为六配位与来自2个不同的C2O42-配体上的4个羧基氧原子和来自2个bimb配体上的2个氮原子配位,呈现畸变的八面体几何构型。