共价功能化碳纳米管的应用研究进展

本文跟踪碳纳米管的功能化研究进展,对共价功能化碳纳米管在材料领域,如复合材料、催化剂载体、电子器件、光学材料、及生物医学中的应用进行了综述.     

石墨烯及其复合材料在水处理中的应用

石墨烯(graphene,GE)是一种由sp2杂化的碳原子以六边形排列形成的周期性蜂窝状二维碳质新材料,具有比表面积大、电子迁移率高和化学稳定性强等特性。本文重点总结了近年来石墨烯及其复合材料应用于水处理吸附剂及光催化剂两个方面的研究进展。石墨烯及其复合材料对于处理重金属、有机污染物等污染物质的吸附效果好,吸附容量高;与光催化材料结合后,石墨烯由于其独特的物理化学特性有效增强了复合材料的光催化特性。最后对各种石墨烯及其复合材料在水处理中的应用作出了评价,同时对它们在水处理中的应用前景做了展望。     

碳纳米管/半导体复合材料光催化研究进展

碳纳米管具有良好的机械性能和导电性、高化学稳定性、大表面积以及独特的一维结构,与半导体光催化剂结合能够增强催化剂的吸附能力、提高光催化效率、扩展光响应范围,而且有利于回收催化剂,极大地提高了半导体光催化剂的综合性能。本文首先分析了半导体光催化剂和碳纳米管的特点,总结了碳纳米管增强半导体光催化的机理,然后分别从复合材料制备方法、复合半导体种类和典型的应用三个不同角度,归纳总结了近年来碳纳米管/半导体复合材料光催化的研究进展,最后对其发展趋势作了展望。     

基于含铬革屑制备吸附-降解型胶原/ZnO复合材料

危险废弃物含铬革屑的资源化利用是制革行业面临的一大难题.含铬革屑的主要成分胶原可作为吸附材料,但存在稳定性差、需解吸等问题,限制了其在水处理领域的应用.本文通过酸法从含铬革屑中提取胶原纤维并原位负载纳米氧化锌(ZnO)制备了吸附-降解型胶原/ZnO复合材料.红外光谱及X射线衍射谱图显示,ZnO成功负载且呈片状,具有六角纤锌矿晶型,负载到胶原纤维上后并不会影响其自身的光响应范围,禁带宽度为3.20 eV.当锌前驱体溶液浓度为0.12 mol/L、胶原纤维分散液pH值为8、胶原海绵质量为60 mg时,复合材料光催化性能最佳;在160 min内对10 mg/L亚甲基蓝(MB)的降解率达95.2%;循环5次后,降解率依然可达到87.5%.动力学模型拟合结果显示,复合材料对MB的吸附更符合拟二级吸附动力学模型,受化学吸附控制;MB的光催化降解过程符合一级降解动力学方程,降解速率最高为0.0172 min^-1.此外, ZnO的引入提高了复合材料的抗菌性和热稳定性.     

碳纳米管/半导体纳米复合材料的光电化学特性及其应用

光电化学过程是在光作用下的电化学过程,它是光伏电池,光电催化等实际应用的基础,是当前十分活跃的研究领域。碳纳米管具有很高的热稳定性,良好的导电能力,大的比表面积,被认为是半导体纳米粒子的有效载体,其独特的一维结构可以为电子提供有效的传输路径。碳纳米管与半导体材料复合,能实现碳纳米管和半导体在结构和性能上的协同,近年来在光电化学领域受到了广泛的关注。本文基于国内外最新研究进展,结合本课题组的研究成果,综述了碳纳米管/半导体复合材料的光电协同作用机理及其在太阳能电池、光电催化降解污染物、光电协同分解水制氢领域中的应用。     

多金属氧酸盐光催化降解有机污染物研究进展

光催化作为一种高级氧化技术在有机污染物的降解方面得到广泛研究。本文概述了多金属氧酸盐光催化降解有机卤化物、染料、农药等有机污染物的研究进展,介绍了多金属氧酸盐与半导体氧化物、层状双氢氧化物、分子筛与介孔材料、离子交换树脂形成的复合材料,以及与半导体氧化物、聚乙烯醇等形成的复合膜材料的相关研究。     

碘钨酸银/碳纳米管复合材料的制备及其光催化应用初探

本文采用水热合成法制备碘钨酸银/碳纳米管复合材料和碘钨酸银单一材料,并对其进行扫描电子显微镜、X-射线粉末衍射、红外光谱表征、紫外-可见光漫反射以及电化学性质的测试。初步探究其光催化性能,实验结果表明,碘钨酸银/碳纳米管复合材料的催化性能较好,其光催化降解亚甲基蓝在60分钟可达到85.4%。     

碳纳米管/氧化锌纳米复合材料的制备及其形貌控制

0引言碳纳米管(CNT)优良的力学、电学、热学性能使其在材料、储能、传感等许多领域都有广泛的应用前景,近年来,以碳纳米管为载体制备的纳米复合材料因其独特的应用潜力而受到广泛关注:彭峰等[1]用FeSO4-H2O2体系修饰碳纳米管,成功地制备了由碳纳米管负载的Fe2O3催化剂;Chen等[2]用溶胶凝胶法制备了CNT/SnO复合材料,作为Li离子电池阴极材料,测试表明它的电化学性能比单独的CNT和SnO材料都有所增强;Jitianu等[3]用溶胶凝胶和水热方法得到不同形貌的TiO2/CNT复合结构,这种新型的纳米复合材料在光催化方面有着重要的应用前景。纳米Z…     

Bi_4V_2O_(11)/石墨烯异质结光催化剂的制备及其在降解抗体污染物中应用（英文）

发展和设计高效、廉价和稳定的光催化剂用于抗生素污染物降解仍然存在巨大的挑战。本文通过一种便捷的水热方法制备了Bi_4V_2O_(11)/石墨烯复合材料并用于可见光下抗生素污染物光催化降解。通过自由基追踪实验,确认了光催化降解过程中活性物质为h+和·OH基团。根据实验结果,提出了相应的反应机理。石墨烯的引入可以有效地促进光生电子-空穴对的分离,从而增强光催化活性。该复合催化剂展现出良好的活性和稳定性。该方法以石墨烯为载体制备了光催化降解材料,为高性能光催化剂的制备提供了参考。     

基于碳纳米管的超级电容器研究进展

综述了基于碳纳米管及其复合材料作超级电容器的电极材料的研究现状,通过对碳纳米管的改性或与其它材料复合,能有效地提高电容器的电容特性。总结了近几年来在开发超级电容器电极材料领域中对碳纳米管的活化和提高碳纳米管的分散性技术、碳纳米管与过渡金属氧化物复合材料、碳纳米管与导电聚合物复合材料以及碳纳米管与石墨烯复合材料研究的进展。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).