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61.
62.
用延展X射线吸收精细结构光谱(EXAFS)研究了不同温度对Zn(II)-锐钛矿型TiO2吸附产物微观构型和吸附可逆性的影响机制. 宏观的吸附-解吸实验表明, 不同温度下的吸附等温线可以用Langmuir 模型进行较好的描述(R2≥0.990). 随温度升高, 吸附等温线显著升高, Zn(II)在TiO2表面的饱和吸附量由5 ℃时的0.125 mmol·g-1增至40 ℃时的0.446 mmol·g-1; 而体系的不可逆性明显减弱, 解吸滞后角θ由32.85°减至8.64°. 求得体系反应的热力学参数⊿H、⊿S分别为24.55 kJ·mol-1 和159.13 J·mol-1·K-1. EXAFS结果表明, Zn(II)主要是通过共用水合Zn(II)离子及TiO2表面上的O原子结合到TiO2表面上,其平均Zn-O原子间距为RZn-O=(0.199±0.001) nm. 第二配位层(Zn-Ti 层)的EXAFS图谱分析结果表明, 存在两个典型的Zn-Ti 原子间距, 即R1=(0.325±0.001) nm (边-边结合的强吸附)和R2=(0.369±0.001) nm(角-角结合的弱吸附). 随温度升高, 强吸附比例(CN1)基本不变而弱吸附比例(CN2)增加, 两者比值(CN1/CN2)逐渐减小. 该比值的变化从微观角度解释了宏观实验中温度升高, 不可逆性减弱的吸附现象. 相似文献
63.
用延展X射线吸收精细结构(EXAFS)技术并结合密度泛函理论(DFT)研究了Zn(Ⅱ)在锐钛型TiO2表面上微观吸附结构。EXAFS结果表明, Zn(Ⅱ)在吸附时由自由水合状态下的Zn—O六配位八面体结构向四配位四面体结构转化, 中心Zn原子的第二配位层存在两种不同的Zn—Ti距离(R1=0.371和R2=0.332 nm). 用DFT方法对四配位水合Zn离子在簇Ti2O11H14上进行优化后发现, 四配位的Zn—O平均距离为0.200 nm; 外层Zn—Ti结合存在两种稳定的吸附模式: 单角吸附模式和更加稳定的双角吸附模式, 其Zn—Ti距离分别为0.369和0.335 nm. EXAFS结果与DFT计算结果吻合, 说明Zn(Ⅱ)在锐钛型TiO2表面上存在不同的亚稳平衡态吸附结构. 相似文献
64.
65.
The title complex has been synthesized by using terephthalic acid (PTA), 1,10-phenanthroline (phen) and copper monohydrate. It crystallizes in monoclinic space group C2/c with a=2.959 0(2) nm, b=1.466 4(10) nm, c=1.764 3(12) nm, β=105.593(11)°, V=7.372(9)
nm3, Dc=1.489 g·cm-3, Z=8, F(000)=3 416, R1=0.043 6,
wR2= 0.151 9. The crystal structure shows that the copper atom is coordinated with four nitrogen atoms from two phens and one oxygen atom from one terephthalic acid, forming a distorted square-pyramid coordination geometry. The cyclic voltametric behavior of the complex is also reported. CCDC: 277047. 相似文献
66.
67.
A complex {[Co(4,4′-bipy)(H2O)4]·(α-Furacrylic acid)2·(H2O)}n with α-furacrylic acid, 4,4′-bipy and cobaltous chloride hexahydrate has been synthesized by means of hydrothermal way and characterized. Crystal data for this complex: monoclinic, space group P21/c, a=1.147 0(2) nm, b=1.099 9(2) nm, c=1.111 1(2) nm, β=97.829(3)°, V=1.388 7(5) nm3, Dc=1.429 g·cm-3, Z=2, μ(Mo Kα)=0.682 mm-1, F(000)=622, S=1.025, R1=0.035 8, wR2=0.086 1. The crystal structure shows that the cobalt(Ⅱ) ion is coordinated with two nitrogen atoms of two 4,4′-bipy molecules and four oxygen atoms from four water molecules, respectively, giving a distorted octahedral coordination geometry. Adjacent cobalt(Ⅱ) ions are bridged by 4,4′-bipy groups, resulting in a 1D chain structure. The adjacent Co(Ⅱ)-Co(Ⅱ) distance is 1.147 0 nm. The cobalt(Ⅱ) ion isn′ t coordinated with α-Furacrylic acid. The complex molecules form 2D structure through hydrogen bonds. The cyclic voltametric behavior of the complex was also investigated. CCDC: 648243. 相似文献
68.
One novel complex Mn2(phen)2(p-CBA)4(H2O) has been hydrothermally syn- thesized from p-chlorobenzoic acid (p-CBA), 1,10-phenanthroline (phen) and anhydrous man- ganese(Ⅱ) sulfate and then characterized. Crystal data for this complex: monoclinic, space group C2/c, with a = 2.3416(3), b = 1.5604(2), c =1.5605(2) nm, β = 121.048(2)o, V = 4.8849(12) nm3, Dc = 1.510 g/cm3, Mr = 555.26, Z = 8, μ = 0.798 mm-1, F(000) = 2256, GOOF = 1.032, the final R = 0.0393 and wR = 0.0816. The crystal structure shows that two neighboring manganese(Ⅱ ) ions are linked together by two bridge-chelating p-chlorobenzoic groups and one bridging water molecule, forming a cage structure with the Mn–Mn bond distance of 0.3512 nm. Each manganese(Ⅱ ) ion is coordinated by two nitrogen atoms of one 1,10-phenanthroline molecule and four oxygen atoms from three p-chlorobenzoic acid anions and one water molecule, giving a distorted octahedral coordination geometry. The cyclic voltammetric behavior of the complex was also investigated. 相似文献
69.
One novel complex [Co(p-MBA)2(2,2′-bipy)(H2O)]·(H2O) has been synthesized by the reaction of p-methylbenzoic acid with 2,2′-bipyridine in the solvent mixture of water and methanol. It crystallizes in triclinic,space group P1 with a=0.70479(14),b=1.1211(2),c=1.6718(3) nm,α=103.806(3),β=90.795(3),γ=104.207(3)o,V=1.2399(4) nm3,Mr=512.41,Dc=1.373 g/cm3,Z=2,F(000)=532,μ=0.733 mm-1,R= 0.0432 and wR=0.0957. The crystal structural analysis shows that the cobalt atom is coordinated with three oxygen atoms from two p-methylbenzoic acids and one water molecule and two nitrogen atoms from one 2,2′-bipyridine,forming a distorted square-pyramidal coordination geometry. The cyclic voltammetry behavior of the complex is also reported. 相似文献
70.
A new copper complex 2{Cu(C10H8N2)[C8H11O2(COO)](H2O)3}·(H2O)5 with bicycle[2.2.1]hept-2-en-5,6-dicarboxylic acid(H2L) [C7H8(COOH)2], basic copper carbonate and 2,2'-bipyridine has been synthesized in the mixed solvents of methanol and water. It crystallizes in the triclinic system, space group P1, with a = 7.4626(5), b = 11.9779(8), c = 12.9841(8), α = 109.7040(10), β = 98.7550(10), γ = 90.6240(10)o, V = 1077.50(12)3, Dc = 1.538 g/cm3, Z = 1, F(000) = 520, GOOF = 1.065, R = 0.0360 and wR = 0.0950. The copper ion is coordinated with four oxygen atoms from one H2 L molecule and three water molecules together with two nitrogen atoms from the 2,2'-bipyridine molecule, forming a distorted octahedral coordination geometry. The thermal stability and electrochemical properties were also studied. 相似文献