过渡金属离子掺杂Zn3(OH)2V2O7·2H2O的合成及其光催化性质

利用水热法合成了3d过渡金属离子掺杂Zn3(OH)2V2O7·2H2O的微米花结构,其分子式可表达为Zn3-3xM3x(OH)2V2O7·2H2O(其中M=Cu,Co,Ni,Mn;0.001≤x≤0.20)。应用XRD、SEM、TEM、UV-Vis DRS、EDX和BET等分析测试技术对产物进行了表征。结构和形貌分析结果显示过渡金属离子掺杂后产物仍保持Zn3(OH)2V2O7·2H2O的六方晶体结构,微米花由主晶面为(0001)的纳米片组装而成。紫外-可见漫反射光谱显示过渡金属离子掺杂后带边吸收红移,其中以Cu的掺杂产物Zn3-3xCu3x(OH)2V2O7·2H2O最为明显,带边吸收扩展到可见光区。首次对Zn3(OH)2V2O7·2H2O及其不同金属离子掺杂产物Zn3-3xM3x(OH)2V2O7·2H2O进行了可见光催化降解有机污染物的研究,结果显示与其它产物相比掺0.1at%Cu的Zn2.997Cu0.003(OH)2V2O7·2H2O对亚甲基蓝(MB)的可见光催化降解效果最好。对掺杂离子种类、掺杂离子浓度对产物可见光催化性质的影响也进行了考察。     

镧和铈钝化镀锌钢板的研究

采用镧盐和铈盐钝化镀锌钢板,通过醋酸铅点滴,失重,中性盐雾和电化学交流阻抗实验检测试样耐腐蚀性能.实验结果显示镧盐和铈盐钝化试样的耐黑变时间分别为70和44 s;腐蚀速率为1.9979×10-3g·m-3·h-1和3.6523×10-3g·m-2·h-1;抗白锈时间为54和46 h;阻抗值大幅提高;实验结果表明镧盐和铈盐钝化处理能大幅度提高试样耐腐蚀性,镧盐转化膜相对于铈盐转化膜更耐腐蚀.清漆划格实验表明清漆在稀土钝化后的试样表面附着力良好;原子力扫描结果显示稀土转化膜由大量不定型的固体颗粒不均匀沉积而成;EDS检测结果表明镧盐转化膜由O,Fe,Zn和La组成,铈盐转化膜由O,Fe,Zn和Ce组成.     

模拟地热水中304不锈钢管和镀锌钢管的腐蚀与结垢

采用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)和电化学测试的方法研究了304不锈钢管和镀锌钢管在模拟地热水(我国中部平原地热水的环境条件)中的腐蚀与结垢行为.结果表明,不锈钢管的结垢产物为"针"状物,其组成主要为CaCO3和MgCO3;镀锌钢管的腐蚀与结垢产物为"球"状物和"针"状物,其组成主要为Zn(OH)2、ZnO和CaCO3;腐蚀产物与结垢产物在晶核的形成生长过程中往往存在相互作用,同时它们在基材表面的分布对镀锌钢管的进一步腐蚀产生一定的抑制作用.     

镀锌扁钢电力接地材料在NaCl介质中的腐蚀特性

应用极化曲线、电化学阻抗谱和中性盐雾腐蚀试验法,研究电力接地材料镀锌扁钢在5%NaCl溶液中的腐蚀行为,扫描电子显微镜（SEM）、X射线衍射仪（XRD）观察与表征镀锌扁钢样品腐蚀的表面形貌及其产物性质.结果表明,在20～60℃温度范围内,镀锌扁钢腐蚀电流随温度升高而增大,60℃时腐蚀速率达到0.8408mA.cm-2（...     

腐蚀后的镀锌钢板表面电子显微表征

通过扫描电子显微镜及其附带的X射线能谱仪对镀锌钢板表面出现腐蚀锈斑、耐腐蚀性能不合格的原因进行了分析.结果表明：镀锌钢板通过热镀工艺生产出来后,未给予足够的镀后防护,同时长时间露在腐蚀性环境中,受到腐蚀产生了白锈甚至红锈,最终导致其耐腐蚀性能不合格,通过一些改进措施可有效的解决质量问题.     

一种常温三价铬镀锌黑钝化方法

以磷酸铬为主要成膜物,有机羧酸为络合剂,通过添加作为发黑剂的镍钴盐,和一定量的硝酸根、氟化钠和二氧化硅的水溶胶,制备出了镀锌黑钝化常温发黑液,其中性盐雾试验可分别达到挂镀56 h,滚镀48 h,红锈出现时间为120 h和92 h。     

盐湖地区暴露25个月的碳钢表面锈层分析

通过扫描电镜(SEM)、电子探针(EPMA)、X射线衍射(XRD)、红外光谱(IRS)和电化学测试技术分析了碳钢在盐湖大气环境下暴露25个月后上下表面的锈层特征. 结果表明, 碳钢上下表面腐蚀量相似, 锈层中均富有Cl、Mg和Si等外来元素. 两个表面的腐蚀产物都主要由β-FeOOH、Fe8(O,OH)16Cl1.3和少量的γ-FeOOH组成, 最外部分的锈层中还检测到Fe3O4和δ-FeOOH. 电化学测试结果表明, 锈层对基体腐蚀具有抑制作用, 锈层保护性随暴露时间增加而增加.     

锈层对海水淡化一级反渗透产水中碳钢腐蚀行为的影响

采用扫描电镜(SEM)、红外光谱(IR)、X射线衍射(XRD)及电化学方法研究了碳钢在海水及海水淡化一级反渗透(RO)产水中锈层形态及其电化学特性.结果表明,碳钢在两种水体中形成的锈层在结构、成分及功能上具有显著差异,导致其腐蚀情况截然不同.海水淡化一级RO产水中,腐蚀产物γ-FeOOH的还原电位高于碳钢自腐蚀电位,易被还原成Fe3O4,使锈层形成Fe3O4内层及γ-FeOOH外层的双层结构.外锈层很薄,无阻碍氧扩散作用,且因γ-FeOOH的还原加快了腐蚀反应.Fe3O4内层具有良好导电性及Fe2+传递性,使氧还原反应从金属表面转移至内锈层表面进行;同时因其大阴极作用,显著促进了氧还原过程.由于锈层的上述作用,碳钢在一级RO产水中的腐蚀得到了极大加速,其腐蚀速率最终由溶液至内锈层之间的氧极限扩散电流密度决定.防腐方法应能抑制腐蚀产物γ-FeOOH的还原.     

Zn3(OH)2V2O7·2H2O纳米片的水热制备

采用硝酸锌、五氧化二钒和氢氧化钠作为反应物,通过一个简单的CTAB辅助的水热方法制备了Zn3(OH)2V2O7·2H2O纳米片.运用XRD,ICP-AES,FTIR,HRTEM,EDS,FE-SEM对产物的晶相和形貌进行了表征.结果表明CTAB在控制产物的形貌、尺寸分布和自组装过程中起着关键作用.同时我们研究了产物的晶体生长行为和自组装过程.     

激光溅射Cu等离子体与气相C2H5OH团簇的反应

用激光溅射-分子束技术研究了气相中Cu的等离子体与乙醇分子团簇的反应.观察到三种团簇正离子Cu＋(C2H5OH)n、CuO＋(C2H5OH)n、H＋(C2H5OH)n和三种团簇负离子(C2H5OH)nC2H5O－、(C2H5OH)n(H2O)OH－、(C2H5OH)n(H2O)2OH－(n≤12).详细考察了在不同的载气压力下激光烧蚀等离子体作用于脉冲分子束， 以及在一定的压力下等离子体作用于分子束不同位置时，对团簇产物种类和团簇尺寸大小的影响.分析了Cu＋(C2H5OH)n、CuO＋(C2H5OH)n、H＋(C2H5OH)n、(C2H5OH)nC2H5O－、(C2H5OH)n(H2O)OH－、(C2H5OH)n(H2O)2OH－等团簇的产生机理.     

Systematic exploration of a rutile-type zinc(II)-phosphonocarboxylate open framework: the factors that influence the structure

To systematically explore the assembly mechanism of a rutile-type open framework of {[Zn(3)(pbdc)(2)]·2H(3)O}(n) (3) (H(4)pbdc = 5-phosphonobenzene-1,3-dicarboxylic acid) constructed by 3-connected pbdc ligands and 6-connected Zn(3)(CO(2))(4)(PO(3))(2) secondary building units (Zn(3)-SBUs), three major factors including solvothermal procedures, types of solvents and amines, are taken into consideration. Seven novel structures, namely {[Zn(5)(pbdc)(2)(OH)(2)(H(2)O)(4)]·4H(2)O}(n) (1), {[Zn(3)(pbdc)(2)·H(2)O]·(Htea)·H(3)O·2-5(H(2)O)}(n) (2), {[Zn(3)(pbdc)(2)](H(3)O)(2)(dma)}(n) (4), {[Zn(2)(pbdc)(taea)]·3H(2)O}(n) (5), {[Zn(3)(pbdc)(2)(Hpda)(2)]·2H(2)O}(n) (6), {[Zn(5)(pbdc)(2)(Hpbdc)(2)]·2H(2)pz·9H(2)O}(n) (7), {[Zn(3)(pbdc)(2)]·Hpd·H(3)O·4H(2)O}(n) (8) are obtained. The results indicate that the layered-solvothermal method and the isopropanol solvent play crucial roles in the construction of the special anionic open framework of [Zn(3)(pbdc)(2)](2-). Changing these two factors led molecular assembly away from the rutile-type open framework. However, amines play a variable role in the framework, which means that by using appropriate amines, molecular assembly could generate the open framework of [Zn(3)(pbdc)(2)](2-) with pores decorated by amines. These results suggest a different approach towards decorating pores in anionic frameworks with precise structural information.     

Hydrothermal synthesis, structure, and luminescent properties of selected Zn(II)/Cd(II) coordination polymers constructed from 3,5-bis(x-pyridyl)-1,2,4-triazole (x = 3, 4)

Utilizing 3,5-bis(x-pyridyl)-1,2,4-triazole (x-Hpytz, x = 3; x = 4) as multidentate ligands, six novel coordination polymers with Zn(II) or Cd(II) metal ions were prepared: [Zn(3-pytz)(0.5)(OH)(0.5)Cl](n) (1, 1D ladder), {[Zn(3-Hpytz)(H(2)O)(4)] [Zn(3-Hpytz)(H(2)O)(3)·SO(4)]SO(4)·5H(2)O}(n) (2·5H(2)O, 1D chain), [Cd(3-Hpytz)(SO(4))](n) (3, 3D framework), {[Cd(3-Hyptz)SO(4)·3H(2)O]·2H(2)O}(n) (4·2H(2)O, 1D chain), [Zn(4-pytz)Cl](n) (5, 3D framework) and [Zn(2)(4-pytz)(SO(4))(OH)](n) (6, 3D framework). All compounds were obtained from hydrothermal reactions, with the exception of compound 4 which was obtained by solvent diffusion at room temperature. All compounds were characterized by FTIR, elemental analysis and TGA analysis and their structures were determined by X-ray diffraction. All compounds exhibited substantial thermal stability and showed photofluorescent properties that resulted from ligand π-π* transition.     

纳米片状ZnO的室温制备及其胶状前体的稳定性分析

以醋酸锌和氢氧化钠为原料,采用室温直接沉淀法得到了ZnO的前体胶状醋酸锌碱式盐,通过控制pH值,在室温下分别制备了碱式盐Zn5(OH)8(Ac)2·2H2O和六方晶系纤锌矿ZnO,并利用X射线衍射、扫描电子显微镜和能谱(EDS)等测试技术对产物进行表征。 结果表明,采用直接沉淀法在pH值为7的环境下得到了具有{n{[Zn5(OH)8(H2O)2]2+}·(2n-x)Ac-}x+·xAc-胶团结构的稳定胶体体系,室温下干燥后的产物的成分为碱式盐Zn5(OH)8(Ac)2·2H2O;而在pH值为14时,胶状前体发生聚沉生成白色沉淀,室温干燥后得到纳米片状ZnO。 还考察了pH值对胶状前体稳定性的影响,并探讨了ZnO的生成机理。     

Novel iso-reticular Zn(II) metal-organic frameworks constructed by trinuclear-triangular and paddle-wheel units: synthesis, structure and gas adsorption

Two novel Zn(II) metal-organic frameworks (MOFs) constructed by trinuclear-triangular and paddle-wheel units, namely {[Zn(5)(dmtrz)(3)(IPA)(3)(OH)]·DMF·H(2)O}(n) (MAC-4, Hdmtrz = 3,5-dimethyl-1H-1,2,4-triazole, H(2)IPA = isophthalic acid, DMF = dimethyl formamide) and {[Zn(5)(dmtrz)(3)(OH-IPA)(3)(OH)]·DMF·5H(2)O}(n) (MAC-4-OH, OH-H(2)IPA = 5-hydroxyisophthalic acid), were solvothermally synthesized. Single-crystal analyses reveal that MAC-4-OH is an iso-reticular framework of MAC-4 with channels functionalized by hydroxyl groups. Gas adsorption reveals that MAC-4-OH shows a significant enhancement for CO(2) uptake compared with that of MAC-4 due to the existence of electrostatic attractive interactions, though its surface area is lower than that of MAC-4.     

用丝束电极研究模拟碳化混凝土孔隙液中缓蚀剂对碳钢局部腐蚀的抑制行为

应用丝束电极(WBE)的电位/电流扫描技术, 研究了含Cl-的模拟碳化混凝土孔隙液中, Q345B碳钢局部腐蚀在空间和时间上的发生和发展特征, 同时比较了四乙烯五胺(TEPA)和亚硝酸钠缓蚀剂对局部腐蚀抑制能力的差异. 结果表明NO-2离子能快速渗透腐蚀产物层, 并抑制锈层下的碳钢活性溶解, 而乙烯胺由于在锈蚀层内的扩散速率低, 初期反而会促进锈层下的局部腐蚀, 随着烯胺分子扩散并吸附于锈蚀层/金属界面处, 碳钢活性溶解才受到抑制. 电化学阻抗谱(EIS)可反映局部腐蚀的萌发, 但难以表征缓蚀剂在碳钢表面的不均匀吸附特征. 基于丝束电极表面电位/电流分布所提出的局部腐蚀因子(LF), 可定量表征腐蚀的不均匀特征以及缓蚀剂对局部腐蚀的修复能力.     

One pot-synthesis of chiral Ni6 clusters involving Ni3 subunits: a combined structural, magnetic and DFT study

Ni(6) clusters of the general formula [{Ni(3)L(n)(OAc)(OH)}(2)(X)(OAc)(H(2)O)(2)] (n = 1, 2; X = Cl(-) or N(3)(-), (L(n))(3-) = hexadentate tritopic ligands) can be isolated by spontaneous self-assembly, from mixtures of Ni(OAc)(2), H(3)L(n), NMe(4)OH·5H(2)O and NaX in adequate molar ratios. Thus, four new hexanuclear complexes [{Ni(3)L(1)(OAc)(OH)}(2)Cl(OAc)(H(2)O)(2)]·7.5H(2)O (1·7.5H(2)O), [{Ni(3)L(2)(OAc)(OH)}(2)Cl(OAc)(H(2)O)(2)]·2H(2)O·7.5MeOH (2·2H(2)O·7.5MeOH), [{Ni(3)L(1)(OAc)(OH)}(2)(N(3))(OAc)(H(2)O)(2)]·6H(2)O (3·6H(2)O) and [{Ni(3)L(2)(OAc)(OH)}(2)(N(3))(OAc)(H(2)O)(2)]·4H(2)O (4·4H(2)O) were obtained and fully characterised. 1·7.5H(2)O and 2·2H(2)O·7.5MeOH were isolated in the form of single crystals, the latter losing solvate on drying, to yield 2·2H(2)O. Recrystallisation of 3·6H(2)O in MeCN/MeOH also generates single crystals of 3·H(2)O·2MeOH·2MeCN. Their X-ray characterisation shows that these Ni(6) clusters can be considered to be built from two triangular trinuclear [Ni(3)L(n)(OAc)(OH)](+) subunits with different connectors. In addition, these studies demonstrate that the (L(n))(3-) ligands behave as trinucleating, adopting such a conformation that induces chirality in the isolated compounds. In this way, 3·H(2)O·2MeOH·2MeCN appears particularly interesting, since it emerges as homochiral after undergoing spontaneous resolution upon crystallisation. The magnetic characterisation of 1·7.5H(2)O to 3·6H(2)O reveals that the three compounds present an overall antiferromagnetic coupling. The intricate magnetic behaviour of these clusters, mediated by a total of 14 bridges of different kinds, was analysed and satisfactorily interpreted in light of DFT calculations.     

Impact of water on the OH + HOCl reaction

The effect of a single water molecule on the OH + HOCl reaction has been investigated. The naked reaction, the reaction without water, has two elementary reaction paths, depending on how the hydroxyl radical approaches the HOCl molecule. In both cases, the reaction begins with the formation of prereactive hydrogen bond complexes before the abstraction of the hydrogen by the hydroxyl radical. When water is added, the products of the reaction do not change, and the reaction becomes quite complex yielding six different reaction paths. Interestingly, a geometrical rearrangement occurs in the prereactive hydrogen bonded region, which prepares the HOCl moiety to react with the hydroxyl radical. The rate constant for the reaction without water is computed to be 2.2 × 10(-13) cm(3) molecule(-1) s(-1) at room temperature, which is in good agreement with experimental values. The reaction between ClOH···H(2)O and OH is estimated to be slower than the naked reaction by 4-5 orders of magnitude. Although, the reaction between ClOH and the H(2)O···HO complex is also predicted to be slower, it is up to 2.2 times faster than the naked reaction at altitudes below 6 km. Another intriguing finding of this work is an interesting three-body interchange reaction that can occur, that is HOCl + HO···H(2)O → HOCl···H(2)O + OH.