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1.
尝试用氨蒸发诱导合成方法在石墨小片上生长球形Co3O4微粒, 并用其制备电极且进行S2-的电化学氧化研究. 用极化曲线、恒电位技术等电化学方法考察了Co3O4电极对S2-的电化学氧化的催化性能, 发现Co3O4电极对电化学氧化S2-具有优异的催化性能, 极大地促进了-0.40 V 附近S2-向含硫的酸根离子和低级多硫离子的转变, 电流密度最大可以达到580 mA·cm-2. 恒电位极化表明电极的电催化稳定性良好; 电化学阻抗谱(EIS)测试显示Co3O4在碱性S2-电解液中的电荷转移电阻很小, 这从电化学动力学角度解释了它对S2-具有良好的催化性能.  相似文献   

2.
合成了标题化合物Cu(S2CNC4H8NC2H5)2,得到深棕色柱状晶体。晶体属三斜晶系,空间群为P1。中心Cu(Ⅱ)离子分别与来 自2个N′-乙基-N-哌嗪基二硫代氨基甲酸的4个硫原子配位,形成略微扭曲的平面四方配位构型。4个Cu-S键的键长范围0.220 10(11)~0.220 34(13) nm;Cu-S键的FT-Raman伸缩振动峰在134.921 cm-1;ESR谱表明Cu(Ⅱ)离子处于对称中心;其局部配位构型属于D2h群;热分析表明标题化合物在753.15 ℃时分解为金属Cu。  相似文献   

3.
CexPr1-xO2-δ复合氧化物的XRD和Raman表征   总被引:1,自引:0,他引:1  
A series of CexPr1-xO2-δ mixed oxides were synthesized by sol-gel method and characterized by Raman and XRD techniques. When x value was changed from 1.0 to 0.5, only a cubic phase CeO2 was observed. The samples were very well crystallized on decreasing x from 0.50 to 0.99. For CexPr1-xO2-δ samples 465 cm-1 and 1 150 cm-1 Raman peaks are attributed to the Raman active F2g mode of CeO2. The broad peak at about 570 cm-1 in the region of 0.3 ≤x≤ 0.99 can be linked to lattice defects resulting in oxygen vacancies. The new band at about 195 cm-1 may be attributed to the asymmetric vibration caused by the formation of oxygen vacancies. Calcination temperatures had great effect on the peak intensity for CeO2 but less effect on Ce0.8Pr0.2O2-δ in Raman spectra. It might be due to the transformation of the colors for the mixed oxides, the insertion of Pr atom into the ceria lattice could enhance the sintering resistance and thermal stability of the mixed oxides.  相似文献   

4.
郝仕油  吕天喜 《化学学报》2008,66(10):1203-1208
使用Ce(NO3)3•6H2O, Pr(NO3)3•6H2O, La(NO3)3•6H2O, 尿素为原料, 利用微波引诱燃烧法合成了多孔纳米Ce-M-O (M=Pr, La)固溶体. 使用XRD, X光电子能谱仪(XPS), Raman光谱仪, 红外光谱仪(FT-IR), 透射电镜(TEM), 场发射扫描电镜(FE-SEM)等仪器对纳米粉体进行了表征. XRD分析显示Ce-M-O粉体的粒径在20~50 nm之间, 且所有样品均具有萤石结构. XPS证明在Ce-Pr-O固溶体中Pr以+3和+4两种形式存在. Raman光谱表明随着M3+的掺杂, 在CeO2晶格中产生氧缺陷, 且缺陷浓度随掺杂量增加不断提高. 红外光谱证明Ce—O键的吸收峰在1400 cm-1左右, 且由于M3+的掺杂在2346 cm-1的吸收峰消失. TEM照片说明样品具有类盘状的网络纳米微晶结构. 扫描图像说明产物具有多孔的外貌特征, 且孔径分布在2~40 nm之间.  相似文献   

5.
在氧离子导体La2Mo1.7W0.3O9的基础上,采用固相法合成了La位掺杂的Ca系列新型氧化物La2-xCaxMo1.7W0.3O9-δ(0≤x≤0.2)。通过XRD、Raman和XPS等手段对化合物结构进行表征,交流阻抗谱测试其电性能。结果表明:掺杂离子Ca2+的半径小于基质离子La3+的半径导致晶格收缩;Ca的掺杂在La2Mo1.7W0.3O9自身内置氧空位的基础上增加了额外的氧空位,提高了氧离子导体的电导率,550 ℃电导率由0.79 × 10-4 S·cm-1 (x=0.0)增加到1.5 × 10-4 S·cm-1 (x=0.16,0.2),电导率增加89.9%。  相似文献   

6.
基于二茂铁羧酸配体的镉配合物的合成及结构研究   总被引:1,自引:0,他引:1  
以二茂铁甲酸根FcCOO-(Fc=(η5-C5H5)Fe(η5-C5H4))为主要配体,合成了3个新的配合物[Na2Cd( μ32-FcCOO-)222-FcCOO-)2(CH3OH)2]n (1)、[Cd(phen)(FcCOO-)(η2-FcCOO)(H2O)](phen=邻菲咯啉) (2)、[Cd(Det)(η2-FcCOO-)(FcCOO-)](H2O)2(Det=二乙撑三胺) (3)。测定了配合物的晶体结构。配合物1为单斜晶系,C2/c空间群,二茂铁甲酸根采用μ32-FcCOO-和μ22-FcCOO-的配位方式将Cd2+和Na+连接成一维无限链状结构。配合物23均为单核结构,单斜晶系,P21/c空间群,二茂铁甲酸根都采用 FcCOO-和η2-FcCOO-的方式配位。2中phen以双齿螯合形式配位,水分子参与配位,中心镉离子配位数为6。3中Det以三齿螯合形式配位,中心镉离子配位数也为6,但水分子未参与配位。  相似文献   

7.
应用密度泛函理论计算,研究了Ti-MWW分子筛10元环正弦孔道内骨架钛物种的结构和振动光谱。计算采用基于36T簇模型的B3LYP/6-31G(d,p)方法,确定了[Ti(OSi)4]物种优先落位于T3位,在924~987cm-1区域内存在3个振动峰,都属于以Ti为正四面体中心分布的4个Ti-O-Si键的协同伸缩振动,其中958cm-1的振动强度较大,属于[Ti(OSi)4]的特征频率。T2和T8位上钛物种不出现该特征峰。Ti(Ⅳ)中心上吸附一个水分子形成五配位配合物,其特征振动频率没有变化。[Ti(OSi)4]物种进一步水解形成[Ti(OSi)3OH]物种,其Ti-O-Si的特征振动蓝移到969cm-1。此外,还考察了Ti-MWW分子筛中可能存在的骨架硼以及羟基巢的结构和振动光谱,计算频率与已有文献数据相符。  相似文献   

8.
本文合成了9种含有由天然D(+)-樟脑衍生的1R,3S-1,2,2-三甲基-1,3-环戊二胺(A)为配体的铂(Ⅱ)配合物[Pt(Ⅱ)AX]{其中,X=(CH2)3C(COO-)2(1,1-环丁烷二羧酸根),2CH3OCH2COO-,2CH3CH2OCH2COO-,2CH3(CH2)3OCH2COO-,[OCH(CH3)COO]2-(乳酸根),(OCH2COO)2-(乙醇酸根),2CH3OCH2CH2OCH2COO-,2CH3CH2OCH2CH2OCH2COO-和2CH3(CH2)3OCH2CH2OCH2COO-}。通过元素分析、热重分析、红外光谱、1H核磁共振谱和电喷雾质谱等对配合物进行了表征。体外生物活性测试表明,部分配合物对A549人肺癌细胞和HCT-116人结肠癌细胞具有较强的抗肿瘤活性。  相似文献   

9.
利用差示扫描量热法(DSC)建立了无水三氯化铁和氯化正丁基吡啶(BPC)二元体系相图. 依据相图, FeCl3和BPC形成室温离子液体的窗口是x=0.26~0.58; 室温离子液体的深度是80 ℃. 利用UHF/6-31G*对FeCl3, FeCl4, Fe2Cl7等配合物的几何结构、键长、能量和Raman频率进行优化, 从头算和Raman光谱证实了相图中FeCl3摩尔分数x=0.50处有稳定化合物存在, FeCl4是主要阴离子; x=0.67处, FeCl4, Fe2Cl7是主要阴离子.  相似文献   

10.
本文报道了2例由有机磺酸根阴离子调控的单核钴(Ⅱ)配合物[Co(pytpy)2](2-NH2-1-NS)2·MeOH·H2O (1)和[Co(pytpy)2](4-NH2-1-NS)2·H2O (2)的合成、晶体结构和磁性,其中pytpy=4''-(4-吡啶基)-2,2''∶6'',2″-三联吡啶,2-NH2-1-NS-=2-氨基-1-萘磺酸根离子,4-NH2-1-NS-=4-氨基-1-萘磺酸根离子。单晶X射线衍射分析表明,这2例配合物均由[Co(pytpy)2]2+阳离子、有机磺酸根阴离子和结晶溶剂分子组成。其中,阴离子2-NH2-1-NS-和4-NH2-1-NS-仅在磺酸根和氨基的相对位置上有所不同。有趣的是,具有处于邻位的磺酸根和氨基的2-NH2-1-NS-阴离子与[Co(pytpy)2]2+阳离子和溶剂分子形成氢键,而具有处于对位的磺酸根和氨基的4-NH2-1-NS-阴离子之间通过氢键形成了二维层状结构。磁测量表明配合物12的磁性有很大的不同:配合物1具有可逆的渐变型自旋交叉行为,而化合物2则保持在高自旋态。  相似文献   

11.
Mono- and Dinuclear MoII Phthalocyaninates(2–): Syntheses and Properties of Bis(cyano)phthalocyaninato(2–)molybdate(II) and Bis(phthalocyaninato(2–)molybdenum(II)) Blue diamagnetic bis(phthalocyaninato(2–)molybdenum(II)) is synthezied by reduction of oxophthalocyaninato(2–)molybdenum(IV) with boiling triphenylphosphine. The Mo–Mo stretching vibration ist observed in the resonance Raman spectrum at 374 cm–1. It is chemically inert and dissolves in conc. sulfuric acid without decomposition. It reacts with molten tetra(n-butyl)ammonium cyanide to yield redbrown paramagnetic bis[tetra(n-butyl)ammonium] biscyanophthalocyaninato(2–)molybdate(II) (μeff = 3.15 μB; S = 1). The complex salt is very instable and demetallizes in solution. In the extraordinary UV-VIS-NIR spectrum an intense trip-triplet transition at 7780 cm–1 together with a very structured B region between 14000 and 21000 cm–1 of comparable absorbance is observed.  相似文献   

12.
Mixed metal oxides (MMOs) prepared by the mild thermal decomposition of layered double hydroxides (LDHs) differ in their reactivity on exposure to aqueous molybdate containing solutions. In this study, we investigate the reactivity of some T-Al containing MMOs (T=Co, Ni, Cu or Zn) towards the formation of layered transition metal molybdates (LTMs) possessing the general formula AT2(OH)(MoO4)2·H2O, where A=NH4+, Na+ or K+. The phase selectivity of the reaction was studied with respect to the source of molybdate, the ratio of T to Mo and the reaction pH. LTMs were obtained on reaction of Cu-Al and Zn-Al containing MMOs with aqueous solutions of ammonium heptamolybdate. Rehydration of these oxides in the presence of sodium or potassium molybdate yielded a rehydrated LDH phase as the only crystalline product. The LTM products obtained by the rehydration of MMO precursors were compared with LTMs prepared by direct precipitation from the metal salts in order to study the influence of preparative route on their chemical and physical properties. Differences were noted in the composition, morphology and thermal properties of the resulting products.  相似文献   

13.
The reaction of ammonium heptamolybdate with hydrazine sulfate in an aqueous solution of glycine at room temperature yielded colorless crystals of (NH4)4[(NH3CH2CO)2(Mo8O28)] · 2 H2O. The crystal is monoclinic, space group C2/c (no. 15), a = 17.234 Å, b = 10.6892 Å, c = 18.598 Å, β = 108.280°, V = 3253.2 Å3, Z = 4. The crystal structure contains ammonium cations and isolated octamolybdate(4–) anions, [(NH3CH2CO)2(Mo8O28)]4–, with two zwitterionic glycine molecules as ligands.  相似文献   

14.
Photographic Raman spectra were obtained at shifts to ca. 7000 cm–1 for pure water and for a saturated aqueous solution of NaCl using argon ion laser excitation. Raman spectra were also obtained photoelectrically for H2O and D2O between ca. 2500 and ca. 7000 cm–1 using 248-nm excimer laser excitation and boxcar detection. Overtone and combination assignments are presented for H2O and D2O. The first IR OH-stretching overtone from water occurs 215 cm–1 above the first Raman OH-stretching overtone because the IR overtones are dominated by asymmetric stretching. The second OH-stretching Raman overtone from water is estimated to occur near 10,020 ± 20 cm–1, with 9950 cm–1 as a lower limit.  相似文献   

15.
Chemical modifications of protein crystals may be achieved via soaking of reactants from their precipitating solution, through the solvent channel, into the protein matrix. We describe a Raman microscopy approach to follow mercury insertion into cysteine pairs within protein single crystals, via soaking in an aqueous Hg2+ solution. The method has been developed using bovine insulin as the model system. Applying an efficient mercuration protocol, consisting of a first step of disulphide bridge TCEP-induced reduction within the crystal, followed by overnight reaction with a HgCl2 solution, we obtained Hg-derivative crystals. Raman spectra collected on these derivative crystals, kept in the mother liquor, reveal a characteristic Raman band at 335 cm?1, which has been assigned to a –S–Hg–S– bridge. The analysis provides Raman-based markers of mercury binding to cysteines, and thus of mercury intoxication.  相似文献   

16.
Raman spectra of molten NaClO3 and KClO3 and of aqueous solutions of these salts were measured over the frequency interval from 50 to 1200 cm−1|. Infrared emission spectra of the molten chlorates and of chlorate-nitrate mixtures were recorded, and absorption spectra of aqueous sodium and potassium chlorate also were determined. The ν3(e) and ν4(e) modes of ClO3 were split in the molten salt and aqueous solution spectra, and a single, weak band was observed between ca. 80 and 200 cm in the Raman spectra of molten NaClO3 and KClO3.  相似文献   

17.
The structure of ammonium hexafluoroarsenate, NH4AsF6, has been determined by X‐ray diffraction using a single crystal grown from saturated solution in anhydrous HF. NH4AsF6 crystallizes rhombohedral with the KOsF6 structure type, with a = 7.459(3) Å, c = 7.543(3) Å (at 200 K), Z = 3, space group (No. 148). No phase transition was observed in the 100 K–296 K temperature range. The structure is dominated by regular AsF6 octahedra and disordered NH4+ cations. Raman spectrum of a single crystal of NH4AsF6 shows the bands at 372 cm?1, 572 cm?1, 687 cm?1 (AsF6?) and at 3240 cm?1 and 3360 cm?1 (NH4+).  相似文献   

18.
The high-voltage pulsed electric discharge effect (HPED activation) on the Raman spectra of a saturated aqueous solution of sodium nitrate (NaNO3/H2O) in the region of the totally symmetric vibration 1(A) of the NO - 3 anion has been studied. The temperature dependences of the width and frequency of the corresponding spectral line are examined.  相似文献   

19.
Two Mo/SiO2 samples have been prepared by impregnation of silica gel with aqueous solution of molybdophosphoric heteropoly acid or ammonium heptamolybdate. The catalysts were studied by ESR and IR spectroscopy, X-ray diffraction, and XPS. Their activity was measured in the reaction of thiophene hydrodesulfurization. The silica-supported P–Mo heteropoly acid, with a preserved Keggin structure of the heteropoly anion and sulfided by H2S, exhibited two times higher steady conversion in comparison with ammonium heptamolybdate supported on silica at pH=11 and calcined and sulfided at 500°C.  相似文献   

20.
The room temperature polarized Raman spectra of single crystal Li2SeO4 are assigned using a factor group analysis. The internal optic modes of the selenate ion are responsible for Raman bands from 920 to 440 cm−1, the translational optic modes of the lithium occur in the interval from 444 to 290 cm−1 and the external optic modes of the selenate ion are found between 210 and 70 cm−1. The symmetry-based assignments of these bands are discussed.  相似文献   

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