前处理时间对Co_3O_4形貌及光催化性能的影响

以Co Cl2、Na2CO3为原料,以油酸钠(SOA)为表面活性剂,采用水热-热分解法合成了纯相尖晶石结构的Co3O4粉体。利用TG-DTA、XRD和SEM等手段跟踪反应过程,研究了不同水热时间对产物形貌和结构的影响,并根据实验结果分析了可能的反应机理及结构对光催化性能的影响。实验结果表明:制备前驱体的水热时间是影响产物形貌的关键因素,并且终产物的结构形貌很大程度上决定了其光催化性能。     

273 K下Na2CO3-Na2SO4-Na2B4O7-H2O四元体系介稳相平衡的实验研究

采用等温蒸发法研究了四元体系Na2CO3-Na2SO4-Na2B4O7-H2O在273 K时的介稳相平衡及平衡液相的密度. 利用溶解度数据绘制了该四元体系273 K下的相图. 研究结果表明, 该四元体系有异成分复盐2Na2SO4·Na2CO3形成. 相图中有2个共饱点、5条单变量曲线和4个结晶相区. 4个结晶相区分别为盐Na2CO3·10H2O, Na2SO4·10H2O, Na2B4O7·10H2O和2Na2SO4·Na2CO3的结晶区. 复盐2Na2SO4·Na2CO3同时存在于包含Na2CO3-Na2SO4-H2O三元体系的其它四元体系或高元体系中. 在273 K介稳平衡相图中, 碳酸钠以Na2CO3·10H2O形式析出; 硫酸钠以Na2SO4·10H2O的形式析出; 硼酸钠的完整分子式为Na2B4O5(OH)4·8H2O. Na2CO3对Na2B4O7有盐析作用.     

水热条件对立方状Co3O4形貌的影响

研究了原料浓度、溶液酸度、水热反应温度和时间以及陈化方式等条件对立方状Co3O4形貌和粒度的影响,采用XRD,TEM和IR等手段跟踪反应过程,并表征产物,对水热过程中的相转变和尖晶石相Co3O4的水热形成机理进行了初步探讨     

Co3O4表面物种对甲醛氧化催化性能的影响

采用沉淀法制备了Co3O4催化剂,并将催化剂在流动的N2或O2气氛中于不同温度下进行预处理.通过X射线衍射(XRD)、热重-差示扫描量热分析(TG-DSC)、程序升温脱附(O2/CO2-TPD,HCHO-TPSR)和原位漫反射傅里叶变换红外光谱(in situ DRIFTS)等手段对催化剂表面物种进行了表征.结果表明,Co3O4-N2-200催化剂表面存在Co3+不饱和配位中心和丰富的弱配位氧负离子,容易形成双配位的甲酸盐,并转化成单配位的甲酸盐,进一步分解为产物.     

四元体系Na+,K+∥CO32-,B4O72--H2O 298K相平衡研究

采用等温溶解平衡法研究了四元体系Na^ ,D^ //CO3^2-,B4O7^2--H2O 298K时的相关系,该四元体系298K时的溶解度等温图含有5个相区：Na2B4O7.10H2O,K2B4O7.4H2O,Na2CO3.10H2O,K2CO3.3/2H2O和复盐Na2CO3.K2CO3.H2O,7条单变量曲线和3个共饱点,其中NaCO3.K2CO3.H2O K2CO3.3/2H2O K2B4O7.4H2O为相称共饱点,体系中发现了一种新的复盐：Na2CO3.K2CO3.H2O,这种复盐同时存在于含Na^ ,K^ //CO3^2-H2O三元体系的其它四元或高元体系中。     

空气中合成M2B4O7:Eu3+(M=Na,K)荧光体及其性质表征

以M2B4O7(M=Na,K)为基质,在空气中掺杂稀土元素Eu3+得到了Na2B4O7:Eu3+和K2B4O7:Eu3+荧光体.探讨了体系的烧结条件和荧光性质,分析了晶体的结构.结果表明,虽然两种体系的最佳合成条件不同,但是体系中都同时存在[BO4]和[BO3]结构;稀土离子Eu3+的发光以电偶极跃迁5D0-7F2为主,处于非中心对称的格位上,并且可以很好地存在于基质中,Na2B4O7:Eu3+具有较强的发光强度.     

五元交互体系Li+,Na+,K+//CO32-,Cl--H2O在298.15K的相平衡研究

针对西藏扎布耶盐湖卤水组成,采用等温溶解平衡法研究了五元交互体系Li+,Na+,K+//CO32-,Cl--H2O于298.15K时的相平衡,并绘制了相图(空间立体图和Li2CO3饱和的投影图).结果表明,该五元体系相图含有7个结晶区、13条单变量线和4个无变量点.7个结晶区由6个单盐结晶区和1个复盐结晶区组成,分别为LiCl·H2O,NaCl,KCl,Li2CO3,K2CO3·3/2H2O,Na2CO3·10H2O和NaKCO3·6H2O,没有形成固溶体和天然碱(Na2CO3·NaHCO3·2H2O).4个无变量点标记成K1,K2,K3和K4,所对应的平衡固相盐分别是:Li2CO3+NaKCO3·6H2O+Na2CO3·10H2O+KCl,Li2CO3+NaKCO3·6H2O+K2CO3·3/2H2O+KCl,Li2CO3+NaCl+KCl+LiCl·H2O和Li2CO3+NaCl+Na2CO3·10H2O+KCl.     

CO32-/Co2+/Ni2+浓度对混合相纳米Ni(OH)2物化性能的影响

以NiCl2、Co(NO3)2、Na2CO3为主要原料,采用超声波辅助沉淀法制备了混合相纳米Ni(OH)2,研究了Co掺杂比例、缓冲剂Na2CO3用量及反应物Ni2+浓度对Ni(OH)2的晶相结构、形貌、粒径及电化学性能的影响。结果表明,混合相结构的α-Ni(OH)2成分随Co掺杂比例增大而增加。较高的CO32-和Ni2+浓度有利于α-Ni(OH)2的生成。TEM测试表明,样品晶粒呈针状形态,其长径比随着Na2CO3用量增加而减小,平均粒度在60~90 nm之间。将纳米样品以8wt%与工业用微米级β球镍混合制成复合电极,其电极的放电比容量随Na2CO3用量的增加先增大后减小。当Ni2+浓度为0.4 mol.L-1、Na2CO3用量为0.5 g时,其电极(Co含量1.02wt%)的充电效率最高,放电比容量最大,0.5C倍率下高达306.9 mAh.g-1,比纯球镍电极提高30%。探讨了复合电极能较大幅度提高放电比容量的机理,提出纳米α-Ni(OH)2同时充当活化中心起催化作用的观点。     

CoBx/Co3O4电催化剂的制备及其氧析出性能

采用NaBH4溶液处理经水热、热处理步骤制得Co3O4纳米棒,得到表面富含氧空位以及无定型CoBx的Co3O4(CoBx/Co3O4)氧析出(OER)电催化剂。利用X射线衍射(XRD)、场发射扫描电镜(FESEM)、透射电镜(TEM)、X射线光电子能谱仪(XPS)等技术表征了催化剂的物相、微观形貌、元素组成以及表面化学键结构等。通过电化学工作站测试了电极材料的OER活性、稳定性、电化学阻抗等。结果表明,经NaBH4处理后,Co3O4表面高价态Co被还原至低价态Co,最终其表面有无定型CoBx的生成,并含有大量氧空位,有效提升了OER性能。在1.0 mol·L^-1 KOH电解质溶液中,达到10 mA·cm^-2的电流密度时,CoBx/Co3O4所需的过电位由Co3O4的346 mV降至298 mV。     

Co3O4纳米片的制备及对H2O2电还原反应的催化性能简

通过恒电势电沉积和加热处理在泡沫镍基体上制备了Co3O4纳米片. 利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)等手段对纳米片的形貌和结构进行了表征. 采用线性伏安扫描和计时电流技术研究了Co3O4纳米片电极对H2O2的电还原性能. 结果表明,在3.0 mol/L KOH 和 0.4 mol/L H2O2溶液中,当电压为-0.4 V(vs. Ag/AgCl)时,线性伏安扫描电流密度达到-0.386 A/cm2,在1000 s 测试时间内,计时电流密度衰减很小,表明Co3O4纳米片电极对H2O2具有很高的活性和稳定性.     

Synthesis，X－ray Structure and Spectral Propertiesofa Tetra－component Heteropoly Compound

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以α型氢氧化物前驱体制备LiNi_(0.8)Co_(0.15)Al_(0.05)O_2及其电化学性能

本文采用球形Al/Co部分取代α型Ni(OH)2为前驱体成功制备了锂离子电池正极材料LiNi0.8Co0.15Al0.05O2。首先采用氢氧化钠与碳酸钠为沉淀剂合成出Al/Co部分取代α型Ni(OH)2,然后将之与LiOH·H2O混合,最后在氧气气氛中不同温度下热处理8h,即可得到球形LiNi0.8Co0.15Al0.05O2材料。X射线衍射结果表明,LiNi0.8Co0.15Al0.05O2材料为α-NaFeO2相。扫描电镜结果表明,材料颗粒形貌为球形。热重分析结果表明合成LiNi0.8Co0.15Al0.05O2的主反应温度在700～750℃之间。振实密度测试结果表明,750℃下制备的LiNi0.8Co0.15Al0.05O2材料可达2.2g·cm-3。恒流充放电结果表明,该材料在0.5mA·cm-2电流密度下,在3.0～4.3V间的首次充电容量可达210.3mAh·g-1,首次放电容量为179.7mAh·g-1,充放电效率为85.4%。与采用以β-Ni0.85Co0.15(OH)2为前驱体合成的LiNi0.85Co0.15O2和Al掺杂的LiNi0.8Co0.15Al0.05O2相比,尽管其首次放电容量与放电效率都有所降低,但循环性能有所提高,50周期后容量仍为初始容量的89.5%。研究表明,以球形Al/Co部分取代α型Ni(OH)2作为前驱体为球形氧化镍钴铝锂材料的制备提供了一条新的途径。     

The design and fabrication of Co_3O_4/Co_3V_2O_8/Ni nanocomposites as high-performance anodes for Li-ion batteries

The Co_3O_4/Co_3V_2O_8/Ni nanocomposites were rationally designed and prepared by a two-step hydrothermal synthesis and subsequent annealing treatment. The one-dimensional(1D) Co_3O_4 nanowire arrays directly grew on Ni foam, whereas the 1D Co_3V_2O_8 nanowires adhered to parts of Co_3O_4 nanowires.Most of the hybrid nanowires were inlayed with each other, forming a 3D hybrid nanowires network.As a result, the discharge capacity of Co_3O_4/Co_3V_2O_8/Ni nanocomposites could reach 1201.8 mAh/g after100 cycles at 100 mA/g. After 600 cycles at 1 A/g, the discharge capacity was maintained at 828.1 mAh/g.Moreover, even though the charge/discharge rates were increased to 10 A/g, it rendered reversible capacity of 491.2 mAh/g. The superior electrochemical properties of nanocomposites were probably ascribed to their unique 3D architecture and the synergistic effects of two active materials. Therefore, such Co_3O_4/Co_3V_2O_8/Ni nanocomposites could potentially be used as anode materials for high-performance Li-ion batteries.     

一维纳米Co_3O_4,Ag/Co_3O_4及CuO/Co_3O_4的合成与电催化性能(英文)

采用水热合成法制备了Co3O4及复合Ag/Co3O4、CuO/Co3O4一维纳米产品。用XRD,FE-SEM和TEM手段对产品进行了表征。采用循环伏安法研究了合成产品修饰的玻碳电极在碱性溶液中对对硝基苯酚的电催化还原性能。与裸玻碳电极相比,1mmol·L-1的对硝基苯酚在用Co3O4、特别是CuO/Co3O4修饰的玻碳电极上还原的峰电流明显增大,用Ag/Co3O4(Ag/Co原子比分别为1∶5和2∶5)修饰的玻碳电极催化还原对硝基苯酚时,尽管还原峰电流增大不是太大,但其峰电位明显降低(分别降低0.265和0.371V)。     

Hydrothermal Synthesis and Crystal Structure of a Cobalt(Ⅱ) Coordination Polymer: [Co(C2O4)(bix)]n (bix=1,4-Bis(imidazol-1-ylmethyl)-benzene)

<正>A new two-dimensional cobalt coordination polymer has been prepared and fully characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The compound [Co(C_2O_4)(bix)]_n 1 crystallizes in the monoclinic system, space group C2/c, with a = 11.549(3), b = 15.700(3), c = 9.260(2), β = 102.984(3)°, V = 1636.0(6)~3, C_(16)H_(14)CoN_4O_4, M_r = 383.23, D_c = 1.556 g/cm~3, μ(MoKα) = 1.078 mm~(-1), F(000) = 780, Z = 4, the final R = 0.0455 and wR = 0.1286 for 1483 observed reflections (I > 2σ(I)). Of the compound, the Co center is octahedrally coordinated with oxalate acting as a tetra-dentate ligand coordinated to the cobalt atom and each bix serving as a bridging ligand by employing two N-donors to coordinate with the Co center. An infinite {Co_2(C_2O_4)_2}_∞ chain is formed along the a axis. Furthermore, the 1D chains are held together via bix ligands to generate a two-dimensional network structure with 1D coronal-like channels (ca. 5.691 × 15.700).     

顺式-二 (乙二胺 )二硝基合钴 (Ⅲ ) (d,l)酒石酸盐的合成与晶体结构

合成顺式 -二 (乙二胺 )二硝基合钴 (Ⅲ )酒石酸盐cis [Co(en) 2 (NO2 ) 2 ]·1/2C4 H4 O6超分子化合物 ,(C6H18N6O7Co ,Mr=345 .2 ) ,用X射线衍射方法确定了晶体结构。晶体学参数 :单斜晶系 ,空间群P2 1/a ,a =13.90 1(3) ,b =6 .5 2 5 (5 ) ,c=14 483(4 ) ,β =10 1.13(2 )°,V =12 89.1(4 ) 3,Z =4,Dc=1.779g/cm3,μ(CuKα) =10 6 .6 9cm- 1,F(0 0 0 ) =72 0。结构由重原法、直接法和Fourier合成法解出 ,最终偏离因子R =0 .117,Rw=0 .0 74。Co(Ⅲ )与 6个N原子形成变形八面体构型 ,酒石酸阴离子处在 4个Co(Ⅲ )正离子所包围的空穴中。     

Hydrothermal Synthesis and Characterization of a Sandwich-type Tungstophosphate,(1,3-H2dap)8H4[Co4(H2O)2(α-B-PW9O34)2] 2·5H2O

<正>A sandwich-type tungstophosphate, (1,3-H_2dap)_8H_4[Co_4(H_2O)_2(α-B- PW_9O_(34))_2]_2·5H_2O (1,3-dap = 1,3-diaminopropane), was hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR and UV spectroscopy. The title compound crystallizes in triclinic, space group P1 with a = 13.691(3), b = 17.744(4), c = 20.620(5), α =113.466(5), β = 91.184(5), γ = 104.223(5)°, V = 4414.3(17)~3, C_(24)H_(96)Co_8N_(16)O_(145)P_4W_(36), M_r = 10143.09, D_c = 3.816 g/cm~3, μ(MoKα) = 24.210 mm~(-1), F(000) = 4452, Z = 1, the final R = 0.0694 and wR = 0.1519 for 9910 observed reflections (I > 2σ(I)). The compound consists of two sets of tetra-transition metal-substituted sandwich frameworks, [Co_4(H_2O)_2(α-B-PW_9O_(34))_2]~(10-) having an inversion centre. Two lacunary α-B-[PW_9O_(34)]~(9-) Keggin units are linked by a rhomb-like Co_4O_(14)(H_2O)_2 cluster, in which the Co~(2+) ions are coordinated by one water molecule. Isolatedly protonated 1,3-H2dap~(2+) units act as counter-ions to interact with the [Co_4(H_2O)_2(α-B-PW_9O_(34))_2]~(10-) heteropolyanions via hydrogen bonds, resulting in a three-dimensional framework.     

咪唑配位的夹心型杂多化合物Na_9[{Na(H_2O)}_3{Co(C_3H_4N_2)}_3(BiW_9O_(33))_2]·33H_2O的合成，结构和磁性质研究

在pH=7.5的水溶液中，咪唑与Na_2WO_4,Bi(NO_3)_3及Co(NO_3)_2反应，得到 了咪唑配位的新型杂多钨酸盐Na_9[{Na(H_2O)}_3{Co(C_3H_4N_2)}_3(BiW_9O_(33) )_2]·33H_2O，用X射线单晶衍射法及元素分析确定了其结构，晶胞参数为：空间 群P3，a=1.3904(4)nm, b=1.3904(4)nm, c=3.3169(13)nm, γ=120 °,V=5.553(3) nm~3, Z=2, R_1=0.0361，wR_2=0.0507(I>2σ)。杂多阴离子[{Na(H_2O)_3}{Co (C_3H_4N_2)}_3(BiW_9O_(33))_2]~(9-)为夹心式结构，两个三空缺Keggin离子α- B-BiW_9O_(33)~(9-)夹层中的中心离子为交替排列的三个Na(H_2O)~+和三个Co (C_3H_4N_2)~(2+)，中心离子钴的配位数为5，该杂多阴离子具有C_(3v)对称性。 对标题化合物进行了磁性质表征，拟合结果为J=6.90cm~(-1),g=2.10,θ=0.25K， 表明该化合物中的Co(II)三核簇存在着铁磁偶合。     

聚苯胺/ZnFe_2O_4纳米复合物的制备与表征

以Fe(NO3)3·9H2O和Zn(NO3)2·6H2O为原料,采用改进的柠檬酸盐前驱物法合成了片状ZnFe2O4,进一步通过原位聚合反应得到了聚苯胺(PANI)/ZnFe2O4纳米复合物。利用X射线粉末衍射、扫描电子显微镜、透射电子显微镜、红外光谱以及荧光光谱等测试技术对其进行了表征。实验结果表明,通过原位聚合反应PANI沉积在片状ZnFe2O4表面。X射线粉末衍射和红外光谱进一步证实了PANI/ZnFe2O4纳米复合物的生成。ZnFe2O4的引入提高了PANI的荧光发光性能和热稳定性。     

Syntheses and Structures of Two Isomorphous Metal-organic Coordination Complexes Based on 4-Pyrimidin-5-ylbenzoic Acid

The reactions of 4-pyrimidin-5-ylbenzoic acid （HL） with Co（NO3）2·6H2O and Ni（NO3）2·6H2O gave rise to two isomorphous mononuclear coordination complexes, namely, [CoL2（H2O）4] （1） and [NiL2（H2O）4] （2）. Both compounds were characterized by IR spectroscopy and single-crystal X-ray diffraction. X-ray crystallographic analyses reveal that they crystallize in monoclinic, space group P21/n. In the crystal structures of these two complexes, only one nitrogen atom of L coordinates to the metal center, and neither carboxylate group nor another nitrogen atom of L links to Co（Ⅱ） or Ni（Ⅱ）. 2D Layers with significant hydrogen bonds can be observed, and they are further linked by L to form a 3D supramolecular network. Nitrogen atoms are not involved in forming hydrogen bonds, but carboxylic groups of the ligands play an important role in the configuration of this hydrogen-bond layer.