超声强化Keggin型Fe-Mo-Zr杂多酸盐降解染料废水

合成了Fe-Mo-Zr杂多酸盐催化剂,并利用红外光谱(IR)和X射线衍射(XRD)对制得的产物进行了表征,研究了Fe-Mo-Zr杂多酸盐超声降解模拟酸性绿B(AGB)染料废水的效果.结果表明,合成的杂多酸盐具有Keggin型结构,催化剂的投加量、染料的初始浓度及初始pH值、超声频率及超声时间都对降解效果产生一定的影响.当染料浓度为10mg/L,催化剂的投加量为0.6g/L时,在pH为5.0的条件下,用40kHz超声辐射60min,降解率最高可达93.18%.通过动力学分析:降解反应符合一级反应动力学模型,速率常数随初始浓度的增加而减小.     

SnO_2@PW_(12)的制备及对废水中亚甲基蓝的降解

采用简单浸渍法制备了SnO2@PW12催化材料,通过XRD和TEM对其结构进行了表征,研究了该催化材料对有机染料亚甲基蓝降解的催化活性。讨论了催化剂投加量、亚甲基蓝溶液的初始浓度、酸度等对催化降解效果的影响。结果表明,当溶液酸度为pH=4,催化剂用量为50mg/L,浓度为5mg/L亚甲基蓝溶液在30W的紫外灯下照射40min脱色率可达89.72%。SnO2@PW12光催化降解亚甲基蓝为一级动力学反应。     

Keggin型Ni-Mo-Zr杂多酸盐的合成、表征及催化超声降解性能

采用水热合成法制备了Keggin型结构的Ni-Mo-Zr杂多酸盐,并利用红外光谱（IR）和X射线衍射仪（XRD）对合成的产物进行了表征。以酸性绿B（AGB）为目标物,研究了在超声波辐射下,Ni-Mo-Zr杂多酸盐的投加量、染料废水初始浓度、pH值等因素对降解效果的影响。实验结果表明：新合成的杂多酸盐具有Keggin型结构,当催化剂的投加量为0.8 g/L,染料废水的初始浓度为10 mg/L,初始pH=5时,用 40 kHz超声频率辐射60 min,染料废水的降解率最高可达90.2%。通过动力学分析,降级反应符合一级反应动力学模型,降解速率随初始浓度的增加而减小。     

CeO2/γ-Al2O3复合材料制备及其光催化性能研究

以Ce(NO₃)₃·6H₂O及Al(NO₃)₃·9H₂O为原料,NH₄HCO₃为造孔剂,以沉淀法制备了具有介孔结构的CeO₂/γ-Al₂O₃光催化材料。研究了不同NH₄∶Al及Ce∶Al摩尔比等条件下制备CeO₂/γ-Al₂O₃样品的光催化性能。结果表明,所制备CeO₂/γ-Al₂O₃复合材料具有优异的光催化性能,最佳NH₄∶Al及Ce∶Al摩尔比分别为1及0.2,该条件下制备的样品BET比表面积为94.4642 m²·g^-1,孔径为5.8565 nm,对亚甲基蓝(MB)的光催化降解率可达93.59%,动力学常数k为0.0218 m...     

基于Keggin型杂多酸的无机-有机杂化物的合成和光催化活性

采用水热合成方法制备了2个基于Keggin型杂多酸的无机-有机杂化物, 化学式分别为{[Cu₂(4,4′- bipy)₄(H₂O)₄](SiMo₁₂O₄₀)·18H₂O}_n(1)和{[Cu₂(4,4′-bipy)₄(H₂O)₄](PMo₆W₆O₄₀)·18H₂O}_n(2)(bipy=bipyridine). 结构分析 表明2个化合物同构, Cu²⁺是六配位, 分别与4个4,4′-bipy上的N原子和2个水分子上的O原子结合, 形成 [Cu(4,4′-bipy)₂(H₂O)₂]_n²ⁿ⁺二维层状结构. 杂多阴离子通过静电与配位阳离子[Cu(4,4′-bipy)₂(H₂O)₂]_n²ⁿ⁺作用交叉排列在层间. 通过红外光谱、 粉末X射线衍射和固体紫外-可见漫反射光谱等对化合物的性质进行了表征. 研究了所合成化合物对水溶性染料亚甲基蓝的降解活性, 发现2种化合物对于亚甲基蓝均表现出显著的光降解活性, 并对它们的催化机理进行了讨论.     

H2O2/TiO2超声协同光降解活性艳橙的研究

以活性艳橙溶液为模拟废水,通过H₂O₂/TiO₂超声(US)协同作用光降解活性艳橙溶液,探讨了TiO₂催化剂用量、H₂O₂用量、活性艳橙溶液的初始浓度、pH值、TiO₂催化剂锻烧温度等对活性艳橙溶液降解率的影响,并比较了几种不同作用方式对活性艳橙溶液的降解效果.结果表明:UV/H₂O₂/TiO₂/US协同作用降解活性艳橙溶液的效果最好;当活性艳橙溶液的初始浓度为20 mg·L^-1,pH＝5,TiO₂用量为0.4 g·L^-1,H₂O₂用量为0.4 ml·L^-1时,降解率可达92.06%.     

磷钼钨杂多酸修饰金属有机骨架MOF-5复合材料吸附亚甲基蓝

采用水热合成法,在合成金属有机骨架MOF-5的过程中引入活性组分磷钼钨杂多酸(H₆P₂Mo₁₅W₃O₆₂),制备出一种新型吸附剂H₆P₂Mo₁₅W₃O₆₂/MOF-5。 利用H₆P₂Mo₁₅W₃O₆₂/MOF-5材料对亚甲基蓝溶液进行了材料的吸附性能研究,探讨了亚甲基蓝溶液的初始pH值和初始浓度以及不同吸附温度对吸附量的影响。 结果表明,在较低的温度和亚甲基蓝溶液较低的初始pH值的条件下,有利于H₆P₂Mo₁₅W₃O₆₂/MOF-5对亚甲基蓝的吸附。 实验结果能够较好地符合Langmuir吸附等温式以及二级动力学模型,对亚甲基蓝的最大吸附量可达401.6 mg/g。 热力学参数ΔG<0、ΔH<0和ΔS>0,表明H₆P₂Mo₁₅W₃O₆₂/MOF-5对亚甲基蓝的吸附过程是自发、放热的。 此外,还探讨了H₆P₂Mo₁₅W₃O₆₂/MOF-5对甲基紫、孔雀石绿、罗丹明B和甲基橙等其它染料的吸附性能,结果表明,H₆P₂Mo₁₅W₃O₆₂/MOF-5对阳离子染料有较好的吸附效果。     

铜负载聚酰亚胺光-芬顿降解甲基橙研究

采用尿素-氯化胆碱DES辅助制备了铜负载的聚酰亚胺催化剂,并将其应用于光-芬顿降解甲基橙染料。其中,尿素-氯化胆碱DES可作为溶剂和去质子化试剂,使得铜能更好地负载到聚酰亚胺上。同时,通过SEM、XRD、红外光谱、EDS、TEM、XPS等手段对催化材料进行了表征,验证了铜的负载。进一步探究了催化剂用量、H₂O₂用量、pH、光照强度、初始浓度等条件对最终降解效率的影响,通过正交试验对实验条件进一步优化,得出甲基橙初始浓度为10 mg·L^-1、pH=3、光照强度500 W、H₂O₂加量0.15 mL、催化剂用量为0.15 g时,可达到甲基橙的几乎完全降解。     

纳米TiO2复合薄膜光催化降解甲基橙的研究

本文通过Sol-Gel工艺在载玻片表面、多孔陶瓷表面及玻璃纤维表面制得了均匀透明的纳米TiO₂复合薄膜,以甲基橙为研究对象,紫外灯为光源,研究了甲基橙初始浓度、光照时间、催化剂载体比表面、初始溶液的pH值对甲基橙降解率的影响,并比较了半导体耦合薄膜的光催化降解能力.研究结果表明:SnO₂-TiO₂复合膜相对于其它耦合膜及金属(La)掺杂膜有较高的降解率.     

磁性光催化剂BiVO_4/Fe_3O_4降解亚甲基蓝的研究

本文用超声法将磁基体Fe3O4与BiVO4复合,制备了易于固液分离的磁性可见光催化剂BiVO4/Fe3O4,采用X射线衍射(XRD)、透射电子显微镜(TEM)等手段对样品的结构和形貌进行表征。以亚甲基蓝为降解对象,考察了BiVO4/Fe3O4的可见光催化活性,并研究了光催化体系中光催化剂用量、亚甲基蓝初始浓度、溶液的pH值、电子受体的存在对光催化过程的影响。结果表明,催化剂的最佳用量为2.0g/L,亚甲基蓝最佳初始浓度为10mg/L,溶液的最佳pH值为11,加入电子受体K2S2O8时,亚甲基蓝几乎完全降解。催化剂回收后连续使用3次,降解率仍然大于80%。     

Syntheses and X-ray crystal structures of [Co(η-CO3)(NH3)4](NO3)·0.5H2O and [(NH3)3Co(μ-OH)2(μ-CO3)Co(NH3)3][NO3]2·H2O

[Co(η²-CO₃)(NH₃)₄](NO₃)·0.5H₂O and [(NH₃)₃Co(μ-OH)₂(μ-CO₃)Co(NH₃)₃][NO₃]₂·H₂O were prepared by prolonged aerial oxidation of a solution of Co(NO₃)₂·6H₂O and ammonium carbonate in aqueous ammonia. The formation of these side products highlights the richness of the chemistry of these systems and the possibility of by products if methods are not strictly adhered to. The X-ray crystal structures of [Co(η²-CO₃)(NH₃)₄][NO₃]·0.5H₂O and [(NH₃)₃Co(μ-OH)₂(μ-CO₃)Co(NH₃)₃][NO₃]₂·H₂O reveal a monomeric octahedral cobalt center with η²-bound CO₃²⁻ in the former, while the latter consists of a dimeric array where the two cobalt centers are bridged by two OH⁻ and one μ₂-CO₃²⁻ groups with three terminal NH₃ ligands for each Co center. In both complexes extensive hydrogen bonding interactions are evident.     

Syntheses,Crystal Structures and Luminescent Properties of Three New Gallium Complexes Containing Pyridine-2,6-dicarboxylic Acid

Three new gallium complexes formulated as [Ga(PDA)₂][Ga(H₂O)(PDA)(phen)]·4H₂O(1), [Ga(PDA)₂]· (H₂IN)·2H₂O(2) and [Ga(OH)(PDA)(H₂O)]₂(3)(H₂PDA=pyridine-2,6-dicarboxylic acid; phen=1,10-phenanthroline; HIN=isonicotinic acid) have been synthesized under hydrothermal conditions. In the mixed-ligand system of complex 1, PDA^2? and phen are connected to the central Ga³⁺ cation as tri- and bi-dentate ligands, respectively. In complex 2, each Ga³⁺ cation is six-coordinated by two PDA^2? anions octahedrally. Complex 3 shows a binuclear structure, with the bond distance of Ga1-Ga2 being 0.30061(3) nm. The 3D supramolecular structures of the three complexes are constructed via hydrogen bonds and aromatic π-π packing interactions. All the three complexes exhibit intense blue emission at room temperature in the solid state, which are attributed to π^*-π transition centered on the ligands.     

An anionic In(III)-based metal-organic framework with Lewis basic sites for the selective adsorption and separation of organic cationic dyes

An In(Ⅲ)-based metal-organic framework (BUT-29) can selectively absorb cationic dyes in DMF even in the presence of other organic dyes, and has the higher adsorption capacity.     

Syntheses,Structures and Properties of Three Transition Metal Coordination Polymers Based on Semi-rigid 3-Pyridylnicotinamide and S/N-Containing Dicarboxylate Mixed Ligands

Three new coordination complexes, [Co（L）（ADTZ）]·H2O（1）, [Cd（L）（ADTZ）]·H2O（2） and [Zn（L）（ADTZ）]·H2O（3）[L=3-pyridylnicotinamide, H2ADTZ=2,5-（s-acetic acid）dimercapto-1,3,4-thiadiazole], were synthesized under hydrothermal conditions. These complexes were structurally characterized by single-crystal X-ray diffraction analysis and further characterized by infrared spectroscopy（IR）, powder X-ray diffraction （PXRD） and thermogravimetric analysis（TGA）. Complexes 1-3 exhibit the similar 2D double-layer networks based on 1D [M-L], zigzag chains and 1D [M-ADTZ]2n double-chains with different distances between metal ions and with various conformations of ADTZ anions. In complexes 1 and 3, the 2D sheets are extended into a 3D supramolecular frameworks by hydrogen bonding interactions. The subtle effects of the central metal atoms on the structures of the title coordination polymers were discussed. The electrochemical properties of complex 1 and luminescent properties of complexes 2 and 3 were investigated. In addition, complexes 1-3 exhibit photocatalytic activity for dye methylene blue degradation under UV light and show good stability toward photoca- talysis.     

Template-directed Synthesis of Three Metal Oxalates via 4-Connected Building Units

Three novel compounds, [Co（en）3]2[Zr2（C2O4）7]·2H20（HNU-2, en=ethylenediamine）, [Co（NH3）6]· [Ce（CzO4）3（H2O）]·H2O（HNU-3） and [Co（dien）2][Gd（C2On）3]·0.75H2O（HNU-4, dien=dethylenetriamine） were hydro- thermal synthesized based on the templates of [Co（en）3]C13, [C0（NH3）6]C13 and [Co（dien）2]C13, respectively. The Zr4＋ Ce3＋ and Gd3＋ cations are all coordinated by four oxalates to form [M（C2O4）n（H2O）n]m （M=Zr, Ce or Gd; n=0 or 1; m=4 or 5）, which are similar to [In（C2O4）4]5- in NKB-1, and can be regarded as 4-connected building units. The [M（C2O4）a（H2O）n]m units are connected via sharing the bis-bidentate bridging oxalate ligands to form binuclears in HNU-2 and 1D ＂zigzag＂ chains in HNU-3 and HNU-4. cular building units to design 3D open frameworks with It is suggested that these compounds could be used as mole- zeolite topologies.     

Solvothermal Synthesis, Structural Characterization and Properties of Two New Layered Lanthanide Sulfates

Two new layered lanthanide sulfates,[C₁₀H₁₀N₂][Pr₂(SO₄)₄(H₂O)₂](1)and[H₅O₂][Sm(SO₄)₂(H₂O)₃](2)were synthesized via solvothermal reaction and structurally characterized by single-crystal X-ray diffraction(XRD), infrared(IR) spectroscopy, thermal analysis, fluorescent spectra and inductively coupled plasma(ICP). Crystal data for compound 1, triclinic, P space group, a=0.8052(4) nm, b=0.9438(4) nm, c=1.4990(7) nm, α=79.450(5)°, β= 83.703(5)°, γ=74.048(5)°, V=1.0746(9) nm³, Z=2; for compound 2, monoclinic, P2₁/c space group, a=0.6599(11) nm, b=1.8940(3) nm, c=0.8765(14) nm, β=96.596(2)°, V=1.0883(3) nm³, Z=4. Structure analysis indicates that both the compounds exhibit a 2D corrugated layer structure, with protonated 4,4'-bipyridine cations and water dimmers (H₅O₂)⁺ located between the inorganic layers of compounds 1 and 2, respectively. Luminescent properties of compounds 1 and 2 were further investigated.     

Tetra(μ3-hydroxo)hexa(μ2-carboxylato-O,O′)-bridged tetranuclear terbium(III) cubane complex

A novel tetranuclear terbium(III) complex [Tb₄(OH)₄(pybet)₆(H₂O)₈][Tb₄(OH)₄(pybet)₆(H₂O)₇ (NO₃)](ClO₄)₁₄·6H₂O has been synthesized and shown by X-ray crystallography to have a cubane-like Tb₄(μ₃-OH)₄(μ₂-carboxylato-O,O′)₆ core. The ligand pybet is pyridinoacetate, C₅H₅⁺N-CH₂CO₂⁻. Magnetic susceptibility data were measured for this Tb₄ complex in the range of 2.0–320 K and in fields of 1.0 G to 50.0 kG. It is concluded that either there is very weak antiferromagnetic exchange interaction (J = −0.015 cm⁻¹) or there is a small crystal-field splitting of the ⁷F₆ Tb^III ground state.     

还原氧化石墨烯/TiO2纳米复合物制备及其光催化性能

采用一步水热法制备了还原氧化石墨烯-二氧化钛(RGO-P25)纳米复合物.通过透射电子显微镜(TEM)、傅里叶变换红外(FTIR)光谱、X射线光电子能谱(XPS)、X射线衍射(XRD)及紫外-可见漫反射谱(UVVisDRS)对复合材料的结构和光电性能进行了表征.在紫外光照和可见光照条件下,研究了不同复合比例的复合物的光催化降解甲基蓝(MB)的性能.结果表明:在水热过程中氧化石墨烯被还原,通过静电引力相互作用得到了具有较高缺陷的还原氧化石墨烯复合物.随着RGO含量的增加,复合物的禁带宽度由3.00 eV变到2.27eV,复合物的导电性增强.在可见光和紫外光光照条件下, 30 min内1%(w,质量分数)RGO-P25光催化降解甲基蓝的效率都超过了80%.紫外光照条件下, 1%RGO-P25纳米复合物催化降解N3染料, cis-Ru(H₂dcbpy)₂(NCS)₂ (H₂dcbpy = 4, 4'-二羧酸-2, 2'-联吡啶), 30 min内63%(摩尔分数)的染料被降解.与P25(75%锐钛矿, 25%金红石)相比,石墨烯的加入大大提高了光催化效率,有效抑制了电子-空穴对的复合.     

Kinetics and mechanisms of homogeneous catalytic reactions: Part 7. Hydroformylation of 1-hexene catalyzed by cationic complexes of rhodium and iridium containing PPh3

Cationic rhodium and iridium complexes of the type [M(COD)(PPh₃)₂]PF₆ (M = Rh, 1a; Ir, 1b) are efficient precatalysts for the hydroformylation of 1-hexene to its corresponding aldehydes (heptanal and 2-methylhexanal), under mild pressures (2–5 bar) and temperatures (60 °C for Rh and 100 °C for Ir) in toluene solution; the linear to branched ratio (l/b) of the aldehydes in the hydroformylation reaction varies slightly (between 3.0 and 3.7 for Rh and close to 2 for Ir). Kinetic and mechanistic studies have been carried out using these cationic complexes as catalyst precursors. For both complexes, the reaction proceeds according to the rate law r_i = K₁K₂K₃k₄[M][olef][H₂][CO]/([CO]² + K₁[H₂][CO] + K₁K₂K₃[olef][H₂]). Both complexes react rapidly with CO to produce the corresponding tricarbonyl species [M(CO)₃(PPh₃)₂]PF₆, M = Rh, 2a; Ir, 2b, and with syn-gas to yield [MH₂(CO)₂(PPh₃)₂]PF₆, M = Rh, 3a; Ir, 3b, which originate by CO dissociation the species [MH₂(CO)(PPh₃)₂]PF₆ entering the corresponding catalytic cycle. All the experimental data are consistent with a general mechanism in which the transfer of the hydride to a coordinated olefin promoted by an entering CO molecule is the rate-determining step of the catalytic cycle.