掺杂TiO_2对C_4A_3形成及水化性能的影响

研究了掺杂 ＴｉＯ２对Ｃ２Ａ３Ｓ矿物的形成及水化性能的影响在１３００℃保温１ｈ, ＴｉＯ２稳 定过渡产物ＣＡ的作用使Ｃ４Ａ３Ｓ的形成速度降低;在１３００℃保温３ｈ,适量的 ＴｉＯ２增加 Ｃ４Ａ３Ｓ的 形成量;ＴｉＯ２的含量过高,使Ｃ４Ａ３Ｓ的形成量减少并出现 ＣＴ（ＣａＴｉＯ３）．掺杂ＴｉＯ２使Ｃ４Ａ３Ｓ 以四方晶系的结构存在掺杂提高了Ｃ４Ａ３Ｓ的水化反应活性,其原因是晶体结构的畸变     

纳米级ZnO—TiO2复合粉体的制备及其性能表征

利用ＺｎＳＯ４和Ｔｉ（ＳＯ４）２为原料,在合成纳米ＴｉＯ２粉体的基础上,将ＴｉＯ２微粉分散在（ＮＨ４）２ＣＯ３溶液中,进一步将ＺｎＣＯ３的形成沉淀出来,于３００℃煅烧２ｈ,即可制得纳米级ＺｎＯ－ＴｉＯ２复合粉体,其粒径约３０－９５ｎｍ。     

气相氧化法制备超细TiO2粒子的研究进展

四氯化钛气相氧化是制备超细二氧化钛（ＴｉＯ２）粒子的重要方法，主要评述ＴｉＣｌ４氧化反应中ＴｉＯ２粒子的形成过程ＴｉＯ２粒子粒径分布的控制模型以及制备条件对为子形态的影响。     

流态化CVD制备TiO2—Al2O3复合粒子

本文探讨了流态化ＣＶＤ反应器中Ｔｉ（ＯＣ４Ｈ９）４水解制备ＴｉＯ２－Ａｌ２Ｏ３复合粒子新工艺，借助于ＳＥＭ、ＴＥＭ、ＢＥＴ、ＸＲＦ和ＥＰＭＡ等现代测试手段研究了复合粒子结构和包覆过程特征。结果表明，在流态化ＣＶＤ反应器中Ａｌ２Ｏ３超细颗粒以团聚体形式存在，ＴｉＯ２包覆量随Ｔｉ（ＯＣ４Ｈ９）４进料浓度升高而增加，但反应温度影响不大；在包覆过程中，同时存在成核和成膜，成核包覆使复合粒子比表面积增加，成     

流态化CVD制备TiO_2－Al_2O_3复合粒子

本文探讨了流态化ＣＶＤ反应器中Ｔｉ（ＯＣ４Ｈ９）４水解制备ＴｉＯ２－Ａｌ２Ｏ３复合粒子新工艺，借助于ＳＥＭ、ＴＥＭ、ＢＥＴ、ＸＲＦ和ＥＰＭＡ等现代测试手段研究了复合粒子结构和包覆过程特征．结果表明，在流态化ＣＶＤ反应器中Ａｌ２Ｏ３超细颗粒以团聚体形式存在，ＴｉＯ２包覆量随Ｔｉ（ＯＣ４Ｈ９）４进料浓度升高而增加，但反应温度影响不大；在包覆过程中，同时存在成核和成膜，成核包覆使复合粒子比表面积增加，成膜包覆使复合粒子比表面积减小．     

微乳液反应法合成二氧化钛超细粒子

含ＮＨ３．Ｈ２Ｏ和ＴｉＣｌ４的微乳液经混合,反应,得到ＴｉＯ２超细粒子前驱体－水合ＴｉＯ２,用紫外－可见光对不同反应时间ｔ和ω时含产物混合液作跟踪测定,结果表明吸收峰位置随反应进行或ω增大发生红移;     

Al-TiO2-C-Ti-Fe体系反应过程研究

采用ＤＳＣ和ＸＲＤ对不同Ｆｅ含量Ａｌ－ＴｉＯ２－Ｃ－Ｔｉ－Ｆｅ体系的燃烧反应过程进行了研究。结果表明,Ａｌ－ＴｉＯ２－Ｃ－Ｔｉ－Ｆｅ体系的反应是分步进行的。在高温区以金属间化合物的分解及Ｔｉ、Ｃ反应为主;在低温区则随着Ｆｅ含量的不同存在不同的反应：Ａｌ－ＴｉＯ２－Ｃ－Ｔｉ以Ａｌ、Ｔｉ的反应为主,Ａｌ－ＴｉＯ２－Ｃ－Ｔｉ－２０ｗｔ％Ｆｅ以Ａｌ、Ｔｉ及Ａｌ、Ｆｅ反应为主,同时还存在Ａｌ、ＴｉＯ２及Ｆｅ、Ｔｉ反应,而Ａｌ－ＴｉＯ２－Ｃ－Ｔｉ－５０ｗｔ％Ｆｅ则以Ｆｅ、Ａｌ和Ｆｅ、Ｔｉ反应为主。     

高取向锐钛矿TiO2薄膜的MOCVD法制备与表征

采用热壁低压ＭＯＣＶＤ方法，以Ｔｉ（ＯＣ４Ｈ９）４为源在ＳｉＯ２／Ｓｉ衬底上制备出高取向锐钛矿ＴｉＯ２薄膜。用Ｘ射线衍射技术研究了沉积温度和衬底对薄膜的结构和相组成的影响规律，采用ＸＰＳ和ＳＥＭ分别研究了薄膜的组成和形貌，结果表明，当沉积温度为５００＾０Ｃ和６００＾０Ｃ时，薄膜为锐钛矿结构，３００＾０Ｃ和４００＾０Ｃ地，薄膜以无定形结构为主，薄膜的组成为ＴｉＯ２，衬底影响薄膜的相组成，不同沉积温度     

气相反应法合成超细粉末过程中的r~＊叶和晶型的研究

本文以ＳｉＣｌ４－ＮＨ３、ＳｉＣｌ４－Ｏ２、ＳｉＣｌ４－Ｎ２－Ｈ２、ＴｉＣｌ４－ＮＨ３－Ｈ２、ＴｉＣｌ４－Ｎ２－Ｈ２、ＴｉＣｌ４－Ｏ２、ＡｌＣｌ３－Ｏ２等为体系，运用均匀成核理论，研究了平衡常数Ｋｐ、过饱和比Ｓ及临界核半径，ｒ＊等因素对气相反应法中超细粉末的形成及粉末结构状态的影响．结果表明，当２ｒ＊大于某物质的晶格常数时，用气相反应法得到的该物质的超细粉末一般为晶体粉末，反之则得到无定形粉末．     

Ti(OC4H9)4-MAPS体系溶胶-凝胶转变研究

研究了Ｔｉ（ＯＣ４Ｈ９）４－ＭＡＰＳ体系中Ｔｉ（ＯＣ４Ｈ９）４、ＭＡＰＳ、Ｃ２Ｈ５ＯＨ、Ｈ２Ｏ４个原料组分对聚钛硅氧烷产转变规律的影响。结果表明,增大水和Ｔｉ（ＯＣ４Ｈ９）４的用量或降低ＭＡＰＳ和Ｃ２Ｈ５ＯＨ的用量,菜成凝胶;反之,则易形成溶胶。     

Modified solid-state reaction synthesized cathode lithium iron phosphate (LiFePO4) from different phosphate sources

A modified solid-state method was used to prepare LiFePO4. With the aid of deionized water, a mixture containing Fe2O3, NH4H2PO4 (or (NH4)2HPO4), LiOH, glucose and oxalic acid was prepared into fluffy powders, which were heated in a carbon-coated crucible at 700 degrees C for 3 hours to synthesize LiFePO4 without any inert gas flow. For the first time, the roles of NH4H2PO4 and (NH4)2HPO4 on the preparation of LiFePO4 were systematically investigated. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS), revealing that the crystallinity of the LiFePO4 sample prepared from NH4H2PO4 is superior to that prepared from (NH4)2HPO4 and the particle size of the sample prepared from NH4H2PO4 is smaller than that prepared from (NH4)2HPO4. The specific capacity, cycle property and rate capabilities were also compared between the as-prepared LiFePO4 samples. A better electrochemical performance was observed in the sample prepared from NH4H2PO4.     

Optical properties of eu doped M-Ga2S4 (M: Zn, Ca, Sr) phosphors for white light emitting diodes

Eu2+ doped M-thiogallate (MGa2S4, M: Zn, Ca, Sr) phosphors were prepared by solid-state reaction. The dependence of luminescent properties, photoluminescence and cathodoluminescence, on M2+ ions was investigated. ZnGa2S4: Eu2+, CaGa2S4: Eu2+, and SrGa2S4: Eu2+ exhibited a green emission band at 540 nm, 560 nm, and 535 nm, respectively. The red-shift between CaGa2S4: Eu2+ and SrGa2S4: Eu2+ was originated from the radius difference of Ca2+ and Sr2+ ions. However, it did not apply to ZnGa2S4 : Eu2+ despite of smaller radius of Zn2+ ion. The particle size of ZnGa2S4 : Eu2+ was much smaller than those of the other thiogallates, leading to extremely low CL emission.     

New blue phosphorescent iridium complexes containing phenylpyridine and triazole ligands: synthesis and luminescence studies

The synthesis and luminescence of iridium(III) complexes containing new phenylpyridine (C(see test for symbol)N) ligands, 4-Me-4'-F-ppy, 4-Me-4'-CF3-ppy and 4-OMe-4'-CF3-ppy, were studied. These ligands were designed for development of the blue light-emitting iridium complexes by introducing the electron-withdrawing group (F, CF3) and the electron-donating group (Me, OMe) at the para positions of the phenyl and pyridine ligand rings, respectively. As an ancillary ligand, trzl-CMe3 was employed where trzl-CMe3 represents 2-(5-tert-butyl-2H-1,2,4-triazol-3-yl)pyridine. The resulting iridium complexes, Ir(4-Me-4'-F-ppy)2(trzl-CMe3), Ir(4-OMe-4'-CF3-ppy)2 (trzl-CMe3) and Ir(4-Me-4'-CF3-ppy)2(trzl-CMe3) exhibited the blue emission at 472, 484 and 494 nm in CH2Cl2 solution, respectively. Ir(4-Me-4'-F-ppy)2(trzl-CMe3) showed the most hypsochromic shift in photoluminescence (PL) among the complexes prepared herein. In the electroluminescence (EL) spectra, Ir(4-Me-4'-F-ppy)2(trzl-CMe3) and Ir(4-Me-4'-CF3-ppy)2(trzI-CMe3) exhibited the luminescence peak at 437 nm and 496 nm, respectively. In the aspect of blue emission color purity, Ir(4-Me-4'-F-ppy)2(trzl-CMe3) had the CIE coordinates of (0.176, 0.143), very close to the saturated standard blue emission.     

Preparation and characterization of SiO2-pillared H2Ti4O9 and its photocatalytic activity for methylene blue degradation

SiO(2) pillared layered titanate (SiO(2)-H(2)Ti(4)O(9)) was prepared via intercalating organosilanes into the interlayers of the layered K(2)Ti(4)O(9) followed by calcination at 500 degrees C. The resulting materials were characterized using XRD, N(2) adsorption-desorption isotherms, UV-vis spectra, IR spectroscopy and Raman spectroscopy. The photocatalytic activity of SiO(2)-H(2)Ti(4)O(9) was evaluated by photocatalytic degradation of aqueous methylene blue dye (MB). XRD and specific surface area results showed that SiO(2)-H(2)Ti(4)O(9) had an interlayer distance of 1.45 nm and a specific surface area of 148 m(2)g(-1). UV-vis absorption spectrum of SiO(2)-H(2)Ti(4)O(9) showed a red shift, indicative of a narrower band gap compared to K(2)Ti(4)O(9). In addition, SiO(2)-H(2)Ti(4)O(9) showed higher MB adsorption capacity compared to H(2)Ti(4)O(9) and K(2)Ti(4)O(9). MB photodegradation over H(2)Ti(4)O(9), K(2)Ti(4)O(9) and SiO(2)-K(2)Ti(4)O(9) followed zero-order kinetics under our experimental conditions, and the photocatalytic activity of SiO(2)-H(2)Ti(4)O(9) was found to be three times higher than that of K(2)Ti(4)O(9), which could be attributed to the increase of interlayer space and specific surface area of SiO(2)-pillared layered titanate.     

Self-assembled peanut-like Ln3+ (Ln = Tb, Sm, Eu) doped NaLa(WO4)2: phase control and its relevance to luminescence modification

Ln3+ (Ln = Tb, Sm, Eu) doped NaLa(WO4)2 peanuts were successfully self-assembled by a facile EDTA assisted hydrothermal treatment. EDTA played critical roles in the phase and morphology control, which regulated the phase transformation from monoclinic La2(WO4)3 flowers to tetrahedral NaLa(WO4)2 peanuts. La2(WO4)3:Tb3+ exhibited two broad excitation bands at 280 and 340 nm, which are related to the normal and perturb sites of WO4(2-). However, the excitation band for NaLa(WO4)2:Tb3+ shifted to near ultraviolet region and showed only one broad excitation band originating from perturb sites. Under ultraviolet excitation, La2(WO4)3:Tb3+ displayed green light and NaLa(WO4)2:Tb3+ showed blue-green light consisting of WO4(2-) self-activated blue emission and the characteristic Tb3+ emission. It can be clearly seen that the blue emission of WO4(2-) was not sufficiently quenched in NaLa(WO4)2 as that in La2(WO4)3, because the distortions of crystalline lattice for NaLa(WO4)2 may alter the energy migration processes. When doping with Sm3+ and Eu3+, NaLa(WO4)2 peanuts exhibited white color emission which may find practical applications in solid state lighting devices.     

CoFe2与CoFe2O4质量比及MgO稀释对CoFe2@CoFe2O4磁性的影响

采用金属有机盐热分解方法制备了MgO包覆的CoFe₂O₄纳米粒子（CoFe₂O₄@MgO）,然后将CoFe₂O₄@MgO在H₂中还原,接着在空气中氧化制备了一组CoFe₂@CoFe₂O₄@MgO样品;用盐酸溶液溶解CoFe₂@CoFe₂O₄@MgO中的MgO获得另一组样品（CoFe₂@CoF₂O₄）。测量并绘制了CoFe₂@CoFe₂O₄@MgO和CoFe₂@CoF₂O₄的磁化强度随外磁场及温度变化的关系曲线。随着氧化温度升高,CoFe₂@CoFe₂O₄@MgO和CoFe₂@CoF₂O₄的矫顽力H_c、饱和磁化强度M_s、剩磁比M_r/M_s及磁有序状态发生显著变化,这些变化强烈依赖于磁性粒子的各向异性及粒子间的偶极相互作用。     

R型六方铁氧体化学键性质和穆斯堡尔谱位移研究

利用电介质的平均能带模型计算了R型六方铁氧体BaTi2Fe4O11和BaSn2Fe4O11的化学键参数,得到BaTi2Fe4O11的2a、4f、4e、6g各晶位平均共价性分别为0.062、0.354、0.309、0.361;BaSn2Fe4O11的相应晶位平均共价性分别为0.062、0.353、0.183、0.255。应用化学环境因子计算了^57Fe、^119Sn在R结构中的穆斯堡尔同质异能位移,确定了^57Fe、^119Sn的价态和占位情况。     

SO_4~(2-)/ZrO_2型固体超强酸改性及其催化氧化脱除噻吩类硫化物

通过掺杂不同金属元素对SO_4~(2-)/ZrO_2型固体超强酸进行改性,应用共沉淀法制备了一系列固体酸催化剂SO_4~(2-)/ZrO_2、SO_4~(2-)/ZrO_2-ZnO、SO_4~(2-)/ZrO_2-Fe_2O_3、SO_4~(2-)/ZrO_2-CuO、SO_4~(2-)/ZrO_2-Al_2O_3,利用氧气作氧化剂进行催化氧化脱除噻吩硫化物动力学实验.研究结果表明,掺杂了Zn、Fe和Cu的SO_4~(2-)/ZrO_22型催化剂催化氧化效果较SO_4~(2-)/ZrO_2都有明显提高,其中添加了金属Zn的SO_4~(2-)/ZrO_2-ZnO催化氧化效果最好,在反应温度为50℃,能达到100%的脱硫率.对合成的系列固体酸进行了X射线衍射(XRD)、氨程序升温脱附(NH3-TPD)的表征,结果表明,催化剂样品中四方相ZrO_2的含量越高,表面酸含量越大,其催化氧化噻吩硫化物的活性越高.     

Electroreduction of H2O2 by Co3O4 and NiCo2O4 nanowires and beta-Ni(OH)2 nanoplates grown on Ni foam

Nanowires (Co3O4 and NiCo2O4) and nanoplates (beta-Ni(OH)2) grown on Ni foam are successfully prepared by a template-free method and used as cathode electrodes for the electroreduction of H2O2, in an alkaline medium. Catalytic performance is investigated via cyclic voltammetry and chronoamperometry. The Co3O4 and NiCo2O4 nanowire electrodes exhibit much better catalytic activity, stability, and mass transfer properties for H2O2 electroreduction than pressed Co3O4 and NiCo2O4 nanoparticle/carbon/PTFE electrodes. A current density of 101.8 mA cm(-2) and 122.7 mA cm(-2) are respectively achieved on Co3O4 and NiCo2O4 nanowire electrodes at -0.4 V in 0.4 mol/L H2O2, and 3.0 mol/L NaOH solution at room temperature.     

锂离子电池正极材料LiFePO_4在LiBC_2O_4F_2基电解液中的电化学性能

采用循环伏安、交流阻抗和充放电测试等研究了使用LiBC_2O_4F_2基电解液的LiFePO_4/Li电池(LiBC_2O_4 F_2电池)和使用LiPF_6基电解液的LiFePO_4/Li电池(LiPF_6电池)的电化学性能.结果表明,常温下LiBC_2O_4 F_2电池和LiPF_6电池的循环伏安曲线都只有1对对应于Fe~(2+)/Fe~(3+)的氧化还原峰,但是高温下LiPF_6电池的氧化还原峰分裂为多个氧化还原峰,而LiBC_2O_4F_2电池的氧化还原峰却与常温下类似,说明LiBC_2O_4F_2电池在高温下工作能保持较好的稳定性.常温下LiBC_2O_4F_2电池的初始放电容量比LiPF_6电池低,但其具有较高的容量保持率,而且在高温下具有比LiPF_6电池更高的放电容量和更优良的循环性能,如经过50次循环后,LiBC_2O_4F_2电池的容量保持率为92.5%,而LiPF_6电池的容量保持率为78.4%.交流阻抗图谱也表明,使用LiBC_2O_4F_2电池在高温下电池的界面电荷传输反应阻抗比室温下有所下降,说明其具有良好的高倍率性能和高温循环性能.