Two new coordination polymers,[Ln(oba)(ox)0.5(H2O)2]n(Ln = Ho(1),Eu(2);H2oba = 4,4?-oxybis(benzoic acid),H2ox = oxalic acid) have been synthesized under hydrothermal conditions.According to single-crystal X-ray diffraction analyses,complex 1 crystallizes in the monoclinic system,space group P21/c with a = 13.783(2),b =10.0120(15),c = 12.1974(18) ,β = 105.217(2)°,V = 1624.2(4) 3,C15H12O9Ho,Mr = 501.18,Z = 4,Dc = 2.050 g/cm3,F(000) = 964,μ = 4.919 mm-1,λ(MoKα) = 0.71073 ?,GOOF = 1.124,the final R = 0.0239 and wR = 0.0570 for 3310 independent reflections with Rint = 0.0298.Complexes 2 and 1 are isostructural.Oba and ox ligands bridge the Ln(III) ions into 2D layers with(4,4) topology,which are further interlinked into a 3D supramolecular network by hydrogen bonds.TG curves of the two complexes are studied to examine their thermal stabilities.Additionally,complex 2 shows red fluorescence in the solid state at room temperature.
One-dimensional strontium hydroxyapatite(Sr-HAp) nanorods were successfully synthesized by a sim-ple solvothermal method.The products were characterized via X-ray diffraction(XRD),Fourier transform infrared(FT-IR),cold field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),photoluminescence(PL) excitation and emission spectra.The experimental results indicated that oleic acid as a surfactant played a key role in confining the growth of the Sr-HAp powders.A possible formation mechanism of the one-dimensional nanorod was proposed and elaborated.Moreover,the as-obtained Sr-HAp samples showed an in-tense and bright emission band centered at 460 nm under long-wavelength UV light excitation and the contents of NaOH used in the synthetic process had an obvious impact on the optical performance of Sr-HAp powders.The possible luminescent mechanism of the Sr-HAp samples was discussed.
采用反相悬浮聚合法,以(NH4)2S2O8-NaHSO3为引发剂,N,N’-亚甲基双丙烯酰胺(MBA)为初体交联剂,环氧氯丙烷(ECH)为表面交联剂,单体丙烯酸(AA)和丙烯酰胺(AM)与羧甲基纤维素钠(CMC)接枝共聚,制得含有阴离子亲水基团和非离子亲水基团的颗粒状高吸水性树脂,研究了表面交联剂的加入量及表面交联时间对树脂吸水性能、保水性能及使用寿命的影响。结果表明表面强化交联与单一交联的产品相比,具有更高的吸液率、吸液速率、脱水速率和使用寿命。通过表面强化交联,树脂的吸水能力可提高一倍以上。在优化的反应条件下,所得树脂在自来水中的吸水率为114 g g 1,在1%NaCl盐水中的吸水率为69 g g 1,吸收至半饱和量的时间小于15 s,吸收至饱和量只需1 min。吸水后的树脂无黏性、分散性好,具有一定的凝胶强度。
Two types of metal-loaded visible-light-driven photocatalysts,Mo-BiVO4and Ag-BiVO4,were synthesized by wet impregnation method.Material poperties were characterized by UV-vis diffuse reflectance spectroscopy,X-ray diffraction,field emission scanning electron microscopy,X-ray photoelectron spectroscopy and low temperature nitrogen adsorption-desorption.Photocatalytic activity of the obtained materials was investigated through degrading methylene blue(MB) solution under visible-light irradiation.The results reveal that both metal loaded-BiVO4catalysts have monoclinic scheelite structure.Mo and Ag exist as oxides on the surface of the particles.The changes of absorption in visible-light region,band gap(E g) and specific surface area(A BET) caused by loading Ag are more obvious than those caused by loading Mo.But the isoelectric point of Ag-BiVO4decreases less than that of Mo-BiVO4does.Both catalysts show higher photocatalytic activity than pure BiVO4,resulting in the significantly improved efficiency of degradation of MB.And the degradation efficiency of these two metal-loaded BiVO4photocatalysts is similar to each other.However,mechanisms of such enhancement are different.The decrease of isoelectric point helps Mo-BiVO4improve the degradation efficiency.As for Ag-BiVO4,the augmentation of absorption in visible-light region as well as the abatement of E g plays more important roles.
LIU KunJieCHANG ZhiDongLI WenJunCHE PingZHOU HuaLei
