共查询到20条相似文献,搜索用时 15 毫秒
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还原态氧化石墨烯的制备及其对重金属离子的吸附性能 总被引:1,自引:1,他引:1
通过乙二胺(EDA)对氧化石墨烯(GO)进行还原制备了还原态氧化石墨烯(RGO),利用红外光谱、拉曼光谱、热重分析和扫描电子显微镜等技术对制得的RGO进行了表征。 考察了RGO复合材料在静态吸附条件下对Pb(Ⅱ)、Cd(Ⅱ)、Cu(Ⅱ)和Mn(Ⅱ)金属离子的吸附性能。 结果表明,该吸附材料对上述4种重金属离子在25 ℃时的静态饱和吸附量分别为396.6、115.3、54.2和38.6 mg/g。 吸附于RGO上的Pb(Ⅱ)可用0.05 mol/L HCl溶液进行洗脱,再生后的RGO重复使用3次时吸附量能达到首次吸附量的85%。 相似文献
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Lyamina G. V. Knyazeva E. P. Mokrousov G. M. 《Russian Journal of Applied Chemistry》2003,76(6):909-911
Sorption of copper and copper oxide from the alloy surface by poly(methyl methacrylate) doped with alkali metal cations was studied with the aim to develop nondestructive sampling of metals from the surface. The sampling efficiency was studied as influenced by the content of alkali metal cations and water in the polymeric matrix. 相似文献
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K. B. Yatsimirskii L. V. Pisarzevsky 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):417-420
Abstract Ligands containing phosphoryl groups form coordination compounds with different metals. The coordination compounds of such ligands with alkali metal ions are considered. The effective charge of phosphorus atom in phosphoryl group is approximately + 1, and oxygen atom effective charge is approximately -1. Phosphorus and oxygen atoms effective charges depend on the nature of the substituents at phosphorus. 相似文献
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The electronic state density and energy bands of Ag-doped anatase TiO2 are studied by WIEN2k software package based on DFT. The calculation results show that the band-gap of anatase titania became bigger after doping with Ag metal ions. The band-gap transfers from 2.04 to 2.5 eV, but a new energy band appears among the forbidden band after the Ag atom substitution. The interband width of Ag-TiO2 is 0.17 eV, which is located at –0.07 eV; more excitation and jump routes are opened for the electrons. The lowest excitation energy can achieve 1.2 eV, which may allow the photons with lower energy (at longer wavelength, such as visible light) to be absorbed. Ag ions are implanted into the titania nanotube sample by MEVVA (Metal Vapor Vacuum Arc) implanter. The photo-electrochemical response and photo-degradation experiment of titania nanotube samples implanted with Ag ions are tested under UV and visible light; the results indicated that the performance of implanted titania naotubes is enhanced both under UV and visible light; it is worth mentioning that the photocurrent density can reach 0.145 mA/cm2 under visible light, which is 181 times higher than those of pure TiNT, and the k value of degradation methyl orange can obtain 0.30 h-1, which is 71 times higher than that of pure TiNT. All the experimental results are consistent well with the theoretic ones. 相似文献
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Pedro MaroteBernard Durand Jean-Pierre Deloume 《Journal of solid state chemistry》2002,163(1):202-209
Zirconia powders are prepared by reaction of a zirconium precursor with an alkali metal nitrate. The major part of the reactions takes place before the melting points and then the reactions go slowly to completion at 450°C in the molten salts. The roles of the precursor and the alkali metal ion are discussed considering the reaction between two precursors, octahydrated zirconium oxychloride and zirconium tetrachloride, and two nitrates, LiNO3 and NaNO3, and some resulting physico-chemical differences. The obtained zirconia powders contain very small amounts of alkali metal ions which act as stabilizing agent. Their effect on the balance tetragonal-monoclinic ZrO2 depends upon the homogeneity of their distribution which is related to their ability to diffuse inside the bulk of particles and their polarizing power when located mainly on the surface. 相似文献
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目前去除重金属离子的方法较多,其中吸附法因操作简单、经济性好而被广泛使用。多孔氧化物块体材料作为新兴的吸附材料具有比表面积高、机械强度高及可回收性好等特点,但吸附选择性差以及孔结构单一的缺陷限制了其在水体重金属处理中的应用。本文详细叙述了多孔氧化物块体材料的多种制备方法,并分别讨论了各方法的优势及其不足。介绍了近几年研究较多的多孔氧化物块体材料及其制备方法与特性。最后,对多孔氧化物块体材料对Pb、Cd及Cr等重金属离子吸附性能的影响因素及改善措施方面进行了总结分析,并指出多种材料的复合、材料表面的接枝改性及分级多孔结构的构建会增强对重金属离子的吸附性能。期望本文为多孔氧化物块体材料的制备及其在重金属离子吸附方面的应用提供参考。 相似文献
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IntroductionManyresearchgroupsareconductingextensiveresearchtoreplacecrudeoil-basedchemicalswithnaturalgasandcoal-basedchemicals.Itisknownthatstyreneisoneofthemostimportantindustrialmonomers.Currently,styreneisproducedbycatalyticalkylationofbenzenewithethyleneoverA1Cl,-HClcata-lyst,followedbyoxidativedehydrogenationoftheresultantethylbenzeneoverpotassium-promotedironoxidecatalystsL'l.However,thisprocessinvolvestheutilizationofbenzeneandethylene,obtainedfromcrudeoilandpetroleumgas,whichareexp… 相似文献
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Somayyeh Piri Farideh Piri Bahare Rajabi Sahar Ebrahimi Abbasali Zamani Mohammad Reza Yaftian 《中国化学会会志》2015,62(11):1045-1052
Aluminum oxide/polyaniline nanocomposite is prepared by a new and one‐pot method including in situ electrooxidation of aluminum and electropolymerization of aniline. The product has been characterized by elemental analysis, FT‐IR spectroscopy, X‐ray diffraction (XRD), Field Emission Scanning Electron Micrographs (FESEM), and Transmission Electron Micrographs (TEM) techniques. ICP‐OES was used for determination of aluminum in the prepared nanocomposite. A porous structure of the prepared composite has been shown by FESEM images. TEM of the product confirms the presence of exfoliated aluminum oxide nanofibers. The adsorption potentials of the prepared nanocomposite towards Cu2+, Pb2+, Zn2+, Cd2+, Ni2+ and Co2+ ions were evaluated in batch adsorption experiments. The results show that the adsorption efficiency is controlled by aqueous phase pH. The experimental data was well interpreted by considering the Langmuir model. The kinetics of the adsorption processes can be well interpreted by pseudo‐second‐order equation. 相似文献
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Feofilov S.P. Kaplyanskii A.A. Kulinkin A.B. Kutsenko A.B. Vasilevskaya T.N. Zakharchenya R.I. 《Journal of Sol-Gel Science and Technology》2001,21(3):135-145
The paper reviews the studies of sol-gel produced nanocrystalline -Al2O3 and cubic Y2O3 doped with RE3+ and TM3+ ions. The effects of spatial confinement (on nanometer scale) in optical properties of sol-gel produced insulating nanocrystalline oxide materials doped with rare earth and transition metal ions are discussed. The experimental studies showed that in insulators these effects are mostly connected with the changes in the vibrational spectrum and the increased role of the surface in nanocrystals. The transformations between the crystalline forms of Al2O3 and the properties of doped corundum ceramics are studied. The methods of sol-gel synthesis of highly dispersed nanocrystalline -Al2O3 and cubic Y2O3 doped with RE3+ and TM3+ ions in wide range of concentrations are described. It is shown that optical techniques are useful for characterization of sol-gel produced materials. 相似文献
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Chitosan is a polymer, which contains β-1, 4-linked α-amino-2-deoxy-D-glucopyranose repeat units and is easily derived from chitin by N-deacetylation. Since chitosan is biodegradable, relatively nontoxic, nonimmunogenic, much research has been directed toward its use in medical applications[1].It also has been suggested for use as chelating agent for metals, since the primary amino group and hydroxyl functionalities at the ring[2]. Chitosan is only soluble in aqueous solution of some acids, so it becomes a limitation. The carboxymethyl chitosan (CMCS),a water-soluble derivative of chitosan, was synthesized by chemical modification with ClCH2COOH and chitosan[3]. It was amphoteric polyelectolyte with stronger chelating ability for metals because of introduction of-COOH. 相似文献
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以木麻黄树皮为载体制备负载锌、铜金属离子的抗菌剂,探讨了木麻黄树皮载金属抗菌剂对大肠杆菌、金黄色葡萄球菌的抑制作用,并考察了木麻黄树皮载金属抗菌剂在纸张中的应用性能。结果表明,铜、锌离子对大肠杆菌、金黄色葡萄球菌均有很好的抑菌效果,当离子浓度为5 mg/m L时,抑菌圈直径分别为17.1 mm、11.2 mm;木麻黄树皮对金属离子具有很好的负载量,木麻黄树皮载金属离子抗菌剂对大肠杆菌、金黄色葡萄球菌具有很好的抑制作用;随着木麻黄树皮中金属离子含量的增大,对大肠杆菌、金黄色葡萄球菌的抑制作用越明显;木麻黄树皮载金属抗菌剂在纸张中的添加量20%、30%时,抗菌纸张对大肠杆菌、金黄色葡萄球菌的抑菌圈的直径分别由12.7 mm增加到17.9 mm、8.4 mm增加到12.7 mm。 相似文献
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为了获得更多的多肽结构信息,采用结构简单的甘氨酸五肽(简写为GGGGG或G5)作为模型,研究了碱金属离子(Li+、Na+、K+、Rb+)对甘氨酸五肽GGGGG气相解离过程的影响.将一定化学计量比的甘氨酸五肽分别和四种碱金属盐溶液混合后,静置10h,使反应达到平衡.电喷雾质谱结果表明,四种碱金属离子均可以在溶液中与甘氨酸五肽形成非共价复合物,其中主要组分为碱金属离子与G5配合比为1:1和2:1的非共价复合物.质谱碰撞诱导解离(CID)时的碰撞能量为25eV.气相碰撞诱导解离实验结果表明,在配合比为1:1的复合物中,其碎片化程度按照Li+、Na+、K+、Rb+的次序依次减小,Rb+的复合物碎裂过程中生成了不常见的c、z离子;在配合比为2:1的复合物中,其碎片化程度按照Li+、Na+、K+、Rb+的次序依次增大.与1:1的非共价复合物相比,Na+、K+、Rb+的2:1复合物的气相解离显得更加容易.除Li+外,两个碱金属离子对G5的活化能力明显较单个碱金属离子强,它们可以诱导多肽在更多位点断裂,生成更多类型的碎片离子. 相似文献
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采用溶胶-凝胶法制备了掺杂Ce3+、La3+、Ag+、Fe3+的TiO2光催化剂,以考察其薄膜和粉体形式对水中无机氮的光催化去除效果和活性.用所制备的催化剂对含氨氮-亚硝酸氮的混合液进行了光催化脱氮研究.本文利用UV-Vis吸收光谱、XRD和TEM对催化剂进行了表征.同时,对影响TiO2光催化效率的因素:如掺杂金属离子的种类、浓度、涂膜层数、反应液中有无Fe2+、不锈钢和玻璃载体、反应器的构型等进行了探讨,并对今后的研究进行展望.经过2 h紫外光照射反应,实验最佳脱氮效果:金属离子掺杂TiO2薄膜型催化剂总氮去除率在30%左右,金属离子掺杂粉末型催化剂光催化最高总氮去除率可达41.7%. 相似文献
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Angela Mller 《无机化学与普通化学杂志》2005,631(12):2285-2296
The aim of this research report is to give an introduction to a specific solid state reaction applied in the field of alkali metal rich transition metal compounds. The approach is an explorative investigation of the oxidation of transition metals with CdO in the presence of alkali metal oxides and / or compounds with complex anions such as Na2SO4. Thereby, a range of unusual compounds have been obtained and structurally characterized. In particular, low valences and uncommon coordination numbers (C.N.) of the late 3d transition metals, as well as interesting varieties in the anionic part of the structures are accessible. The presented examples were selected mainly in order of their inherent aspects concerning the reactivity, structural features or electronic structures. 相似文献
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The present paper gives an account of different aspects of the tracer diffusion of Cs+ ions in alkali metal bromides. We have measured the diffusion coefficients, D, of cesium ions in 1% agar gel medium at 25 ∘C using a zone-diffusion technique over a concentration range of 5 × 10−5 to 0.1 mol,dm−3. The values of the diffusion coefficients were found to deviate from theory, which are explained on the basis of different
types of interactions occurring in the ion-gel-water system. The study is also focused on the effect of alkali metal bromides
on the obstruction effect and activation energy for the tracer-diffusion of cesium ions in agar gel medium. It is observed
that both parameters, extent of obstruction, ∝, and activation energy, E, decrease with increasing charge density of the cation of the supporting electrolyte. The influence of these trends is explained
on the basis of competitive hydration between the ions and agar molecules, and the relative distortion in the water structure
that is brought about by these different ions and agar molecules. 相似文献