K2FeO4的合成及对含苯酚水溶液中重金属离子的去除性能

以次氯酸钙和九水硝酸铁为原料采用湿化学法合成K₂FeO₄,X射线衍射（XRD）、扫描电子显微镜（SEM）、红外吸收光谱（FTIR）、能量色散谱（EDS）的对比分析表明通过二次重结晶纯化可有效去除粗产品中的杂质,获得纯度更高、晶形更完整的K₂FeO₄晶体。同时研究了K₂FeO₄投加量、时间、溶液pH值、温度、初始离子浓度等因素下,K₂FeO₄对含苯酚水溶液中的Cu（Ⅱ）、Cd（Ⅱ）的去除性能,并通过扫描电子显微分析（SEM）、能量色散谱（EDS）、红外吸收光谱（FTIR）等方法研究了K₂FeO₄对溶液中重金属离子的去除机理。实验结果表明：K₂FeO₄可通过一步反应同时去除溶液中的Cu（Ⅱ）、Cd（Ⅱ）以及苯酚,K₂FeO₄主要通过吸附、共沉淀和表面配位的方式去除溶液中的重金属离子。     

K_2FeO_4的合成及对含苯酚水溶液中重金属离子的去除性能（英文）

以次氯酸钙和九水硝酸铁为原料采用湿化学法合成K_2FeO_4,X射线衍射(XRD)、扫描电子显微镜(SEM)、红外吸收光谱(FTIR)、能量色散谱(EDS)的对比分析表明通过二次重结晶纯化可有效去除粗产品中的杂质,获得纯度更高、晶形更完整的K_2FeO_4晶体。同时研究了K_2FeO_4投加量、时间、溶液pH值、温度、初始离子浓度等因素下,K_2FeO_4对含苯酚水溶液中的Cu髤、Cd髤的去除性能,并通过扫描电子显微分析(SEM)、能量色散谱(EDS)、红外吸收光谱(FTIR)等方法研究了K_2FeO_4对溶液中重金属离子的去除机理。实验结果表明:K_2FeO_4可通过一步反应同时去除溶液中的Cu髤、Cd髤以及苯酚,K_2FeO_4主要通过吸附、共沉淀和表面配位的方式去除溶液中的重金属离子。     

高铁酸三钾钠的合成及其物理化学性质研究

首次提出了一种在浓的NaOH溶液中电合成0.83 mol•L^－1 Na₂FeO₄溶液进而高纯度合成固态K₃Na(FeO₄)₂的方法. 研究了合成条件, 并利用多种实验技术研究了该固态样品的性质. 实验表明, K₃Na(FeO₄)₂晶体在混合的NaOH-KOH溶液中, 其溶解-沉淀平衡曲线符合经验方程式: [Na^＋][K^＋]³[ ]^2.8＝1.4×10^－4 ([K^＋]≤1.01 mol•L^－1);在浓的KOH溶液中其溶解度与K₂FeO₄几乎一致. 和K₂FeO₄晶体不同, 所得K₃Na(FeO₄)₂晶体显示3个红外特征峰(787, 801～802和858～862 cm^－1)并具有P m1 (164)空间群的六方晶胞, 其粉末在Ar气中直到197 ℃才分解, 热稳定性低于K₂FeO₄.     

纳米Ag@AgBr表面敏化K2Ti4O9可见光催化剂的微波合成、表征和光催化活性

利用微波法合成纳米尺寸Ag@AgBr表面敏化K₂Ti₄O₉的复合光催化剂（Ag@AgBr/K₂Ti₄O₉）,并通过SEM、X-射线能量色散谱（EDX）、TEM、选定区域电子衍射（SAED）、XRD、紫外-可见漫反射（UV-Vis Diffuse Reflectance）、XPS等对其进行了表征,同时在可见光下测定催化剂对有机物降解的光催化活性。结果表明,粒径为0.2~0.5μm的Ag@AgBr均匀分散在K₂Ti₄O₉表面,Ag@AgBr/K₂Ti₄O₉对可见光有很好的吸收且Ag@AgBr的担载量影响可见光的吸收。当Ag@AgBr的担载量为25wt%时,复合光催化剂具有最高的光催化活性,光照1h对罗丹明B（RhB）的降解率可达97%。另外,催化剂的担载量和稳定性也做了考察。催化剂较高的光催化活性主要归因于Ag纳米粒子的表面等离子体效应和有效的光生电子-空穴的分离。     

MoS2/g-C3N4复合材料的制备及可见光催化性能

首先在N-甲基吡咯烷酮溶液中超声剥离得到少层的MoS₂,将其与石墨相氮化碳（g-C₃N₄）复合,制得MoS₂/g-C₃N₄复合材料。采用X射线衍射（XRD）,扫描电镜（SEM）,X射线光电子能谱（XPS）,傅里叶变换红外光谱（FTIR）,Raman光谱,紫外-可见漫反射吸收光谱（DRS）和光致荧光（PL）技术对复合材料进行表征。可见光下考察MoS₂/g-C₃N₄复合材料光催化降解罗丹明B（RhB）的活性,结果表明：将少量MoS₂与g-C₃N₄复合可明显提高光催化活性,且1%（w/w）MoS₂/g-C₃N₄复合物的光催化活性最高,可能的原因是MoS₂和g-C₃N₄匹配的能带结构,增大了界面间电荷的传输,降低了光生电子-空穴的复合,进而提高了光催化活性。     

基于N-乙酰-L-半胱氨酸修饰的ZnFe2O4@SiO2纳米材料手性识别酪氨酸对映异构体

我们将N-乙酰-L-半胱氨酸（NALC）修饰于ZnFe₂O₄@SiO₂纳米材料表面,制备了一种新型的手性纳米复合物（ZnFe₂O₄@SiO₂-NALC）,该材料能够简便、快速及高选择性地识别手性酪氨酸（Tyr）对映体。利用X射线粉末衍射（XRD）、红外光谱（FT-IR）、能量色散X射线光谱（EDS）、扫描电子显微镜（SEM）、高分辨率透射电子显微镜（HRTEM）和振动样品磁力计（VSM）等一系列表征手段对首次合成出的ZnFe₂O₄@SiO₂-NALC进行测试表征,并将其应用于对手性识别领域的探究。实验结果表明,利用光谱技术（紫外-可见光谱和荧光光谱）,ZnFe₂O₄@SiO₂-NALC可对Tyr对映异构体进行手性识别。此外,我们进一步对Tyr浓度和pH值等实验参数进行了优化。     

Li2SO4-Na2SO4-H2O和Li2SO4- K2SO4-H2O溶液的体积性质

本文用高精度数字式振荡管密度计测定了288K至318K温度范围内Li₂SO₄ + Na₂SO₄ + H₂O和 Li₂SO₄ + K₂SO₄ + H₂O三元体系的密度。混合溶液的离子强度范围从0.1到4.5 mol.kg_–1,混合溶液中Na₂SO₄和K₂SO₄的离子强度分数为0.2,0.4,0.6和0.8。用密度实验值拟合得到了不同温度下Pitzer离子相互作用模型混合参数θ_V和 ψ_V,模型的计算值与实验值的偏差在±0.002 g.cm_–3以内。用Pitzer模型计算了不同离子强度下三元体系的混合体积。     

等离子体辅助法合成α-Si3N4/SiO2纳米梳

晶体的α-Si₃N₄内核和非晶的SiO₂外壳组成的纳米梳通过简单的直流电弧方法合成。通过X射线衍射（XRD）、扫描电子显微术（SEM）、透射电子显微术（TEM）、傅里叶红外光谱（FTIR）等对纳米梳进行表征。纳米梳的光致发光谱展现了两个强的发光峰,分别在450和511nm。α-Si₃N₄/SiO₂核壳结构纳米梳生长机制为等离子体辅助气-固生长机制。     

自组装α-Fe2O3亚微米球的制备及其光催化性质

在乙二醇体系中, 通过简单的二步方法成功合成了α-Fe₂O₃亚微米球。第一步,以Fe(NO)₃和C₆H₁₂N₄为主要反应物160 ℃溶剂热反应8h制备出前驱体;第二步,煅烧前驱体成功合成了斜方相的α-Fe₂O₃产物。利用X射线粉末衍射(XRD),扫描电子显微镜(SEM),透射电子显微镜(TEM),红外吸收光谱(FTIR),能谱分析(EDS)和热重分析(TGA)等手段对产物进行了表征。在300 W紫外灯(主波长为365 nm)照射下降解一定浓度的甲基橙溶液,研究不同光催化剂对甲基橙溶液降解效果。由于制备产物的形貌和粒径影响其比表面积和对反应物的吸附能力以及带隙能,使得制备产物具有良好的光催化性能。结果表明,α-Fe₂O₃亚微米球在紫外光照射条件下对甲基橙溶液有光降解作用。     

Co2+/Cd2+复合材料的合成及其催化性质

在相同的反应条件下,基于配体（Hpypymba=4-（（3-（吡嗪-2-基）-1H-吡唑-1-基）甲基）苯甲酸）和过渡金属离子（Co（Ⅱ）、Cd（Ⅱ））合成同构金属掺杂材料[Co_xCd_1-x（pypymba）₂]_n（0 ≤ x ≤ 1）（配合物1~5）,运用粉末X射线衍射（PXRD）、紫外等分析手段对其结构与形貌进行表征。将得到的MOFs作为催化剂载体负载Ag离子进行4-硝基苯酚的还原反应。研究表明含Co²⁺的化合物1是良好的催化剂载体,随着配合物中Cd²⁺比例的增加,反应速率下降,甚至对反应有一定的抑制效果。该MOFs对于Ag的最大负载量为47%（w/w）,Ag@compound 1经4次循环后依然有96%的催化效率。     

Sol-gel synthesis of K3InF6 and structural characterization of K2InC10O10H6F9, K3InC12O14H4F18 and K3InC12O12F18

K₃InF₆ is synthesized by a sol-gel route starting from indium and potassium acetates dissolved in isopropanol in the stoichiometry 1:3, with trifluoroacetic acid as fluorinating agent. The crystal structures of the organic precursors were solved by X-ray diffraction methods on single crystals. Three organic compounds were isolated and identified: K₂InC₁₀O₁₀H₆F₉, K₃InC₁₂O₁₄H₄F₁₈ and K₃InC₁₂O₁₂F₁₈. The first one, deficient in potassium in comparison with the initial stoichiometry, is unstable. In its crystal structure, acetate as well as trifluoroacetate anions are coordinated to the indium atom. The two other precursors are obtained, respectively, by quick and slow evaporation of the solution. They correspond to the final organic compounds, which give K₃InF₆ by decomposition at high temperature. The crystal structure of K₃InC₁₂O₁₄H₄F₁₈ is characterized by complex anions [In(CF₃COO)₄(OH_x)₂]^(5−2x)− and isolated [CF₃COOH_2−x]^(x−1)− molecules with x=2 or 1, surrounded by K⁺ cations. The crystal structure of K₃InC₁₂O₁₂F₁₈ is only constituted by complex anions [In(CF₃COO)₆]³⁻ and K⁺ cations. For all these compounds, potassium cations ensure only the electroneutrality of the structure. IR spectra of K₂InC₁₀O₁₀H₆F₉ and K₃InC₁₂O₁₂F₁₈ were also performed at room temperature on pulverized crystals.     

Li2O-TiO2-SiO2-P2O5和Li2O-TiO2-Al2O3-P2O5体系锂离子固体电解质的制备及性能研究

一些具有NASICON型网格结构的固体电解质具有高的电导率和好的稳定性,NASICON的意思是Na Super Ionic Conductor[1]。当NaZr2(PO4)3中P5 被Si4 部分取代时便可以得到具有NASICON结构的Na1 xZr2SixP3-xO12体系,其具有高的钠离子电导率。然而有相同结构的Li1 xZr2SixP3-xO12体系的离子电导率却很低,这是因为Li 半径太小,而NASICON三维网格结构的离子通道太大,两者不匹配而使电导率下降[2]。但当LiZr2(PO4)3中Zr4 被离子半径小些的Ti4 取代,所得LiTi2(PO4)3的通道就与Li 半径相匹配,适合于锂离子的迁移,从而使其电导率…     

Non-centrosymmetric Ba3Ti3O6(BO3)2

The compound previously reported as Ba₂Ti₂B₂O₉ has been reformulated as Ba₃Ti₃B₂O₁₂, or Ba₃Ti₃O₆(BO₃)₂, a new barium titanium oxoborate. Small single crystals have been recovered from a melt with a composition of BaTiO₃:BaTiB₂O₆ (molar ratio) cooled between 1100°C and 850°C. The crystal structure has been determined by X-ray diffraction: hexagonal system, non-centrosymmetric space group, a=8.7377(11) Å, c=3.9147(8) Å, Z=1, wR(F²)=0.039 for 504 unique reflections. Ba₃Ti₃O₆(BO₃)₂ is isostructural with K₃Ta₃O₆(BO₃)₂. Preliminary measurements of nonlinear optical properties on microcrystalline samples show that the second harmonic generation efficiency of Ba₃Ti₃O₆(BO₃)₂ is equal to 95% of that of LiNbO₃.     

Synthesis, crystal structure, infrared and Raman spectra of Sr4Cu3(AsO4)2(AsO3OH)4·3H2O and Ba2Cu4(AsO4)2(AsO3OH)3

The two new compounds, Sr₄Cu₃(AsO₄)₂(AsO₃OH)₄·3H₂O (1) and Ba₂Cu₄(AsO₄)₂(AsO₃OH)₃(2), were synthesized under hydrothermal conditions. They represent previously unknown structure types and are the first compounds synthesized in the systems SrO/BaO-CuO-As₂O₅-H₂O. Their crystal structures were determined by single-crystal X-ray diffraction [space group C2/c, a=18.536(4) Å, b=5.179(1) Å, c=24.898(5) Å, β=93.67(3)°, V=2344.0(8) Å³, Z=4 for 1; space group P4₂/n, a=7.775(1) Å, c=13.698(3) Å, V=828.1(2) Å³, Z=2 for 2]. The crystal structure of 1 is related to a group of compounds formed by Cu²⁺-(XO₄)³⁻ layers (X=P⁵⁺, As⁵⁺) linked by M cations (M=alkali, alkaline earth, Pb²⁺, or Ag⁺) and partly by hydrogen bonds. In 1, worth mentioning is the very short hydrogen bond length, D···A=2.477(3) Å. It is one of the examples of extremely short hydrogen bonds, where the donor and acceptor are crystallographically different. Compound 2 represents a layered structure consisting of Cu₂O₈ centrosymmetric dimers crosslinked by As1φ₄ tetrahedra, where φ is O or OH, which are interconnected by Ba, As2 and hydrogen bonds to form a three-dimensional network. The layers are formed by Cu₂O₈ centrosymmetric dimers of CuO₅ edge-sharing polyhedra, crosslinked by As1O₄ tetrahedra. Vibrational spectra (FTIR and Raman) of both compounds are described. The spectroscopic manifestation of the very short hydrogen bond in 1, and ABC-like spectra in 2 were discussed.     

A new 2212-type stair like structure: Bi14Sr21Fe12O61, m=5 member of the generic [Bi2Sr3Fe2O9]m[Bi4Sr6Fe2O16] family

A new oxide, Bi₁₄Sr₂₁Fe₁₂O_61, with a layered structure derived from the 2212 modulated type structure Bi₂Sr₃Fe₂O₉, was isolated. It crystallizes in the I2 space group, with the following parameters: a=16.58(3) Å, b=5.496(1) Å, c=35.27(2) Å and β=90.62°. The single crystal X-ray structure determination, coupled with electron microscopy, shows that this ferrite is the m=5 member of the [Bi₂Sr₃Fe₂O₉]_m[Bi₄Sr₆Fe₂O₁₆] collapsed family. This new collapsed structure can be described as slices of 2212 structure of five bismuth polyhedra thick along , shifted with respect to each other and interconnected by means of [Bi₄Sr₆Fe₂O₁₆] slices. The latter are the place of numerous defects like iron or strontium for bismuth substitution; they can be correlated to intergrowth defects with other members of the family.     

Ion-beam irradiation of lanthanum compounds in the systems La2O3-Al2O3 and La2O3-TiO2

Thin crystals of La₂O₃, LaAlO₃, La_2/3TiO₃, La₂TiO₅, and La₂Ti₂O₇ have been irradiated in situ using 1 MeV Kr²⁺ ions at the Intermediate Voltage Electron Microscope-Tandem User Facility (IVEM-Tandem), Argonne National Laboratory (ANL). We observed that La₂O₃ remained crystalline to a fluence greater than 3.1×10¹⁶ ions cm⁻² at a temperature of 50 K. The four binary oxide compounds in the two systems were observed through the crystalline-amorphous transition as a function of ion fluence and temperature. Results from the ion irradiations give critical temperatures for amorphisation (T_c) of 647 K for LaAlO₃, 840 K for La₂Ti₂O₇, 865 K for La_2/3TiO₃, and 1027 K for La₂TiO₅. The T_c values observed in this study, together with previous data for Al₂O₃ and TiO₂, are discussed with reference to the melting points for the La₂O₃-Al₂O₃ and La₂O₃-TiO₂ systems and the different local environments within the four crystal structures. Results suggest that there is an observable inverse correlation between T_c and melting temperature (T_m) in the two systems. More complex relationships exist between T_c and crystal structure, with the stoichiometric perovskite LaAlO₃ being the most resistant to amorphisation.     

Raman scattering investigations on lanthanum-doped Bi4Ti3O12-SrBi4Ti4O15 intergrowth ferroelectrics

The ferroelectric ceramics of Bi₄Ti₃O₁₂, SrBi₄Ti₄O₁₅, and lanthanum-doped Bi₄Ti₃O₁₂-SrBi₄Ti₄O₁₅ were synthesized, and their Raman spectra were investigated. La-doping resulted in the enlargement of remnant polarization of Bi₄Ti₃O₁₂-SrBi₄Ti₄O₁₅. The structure of the Bi₂O₂ layers and TiO₆ octahedra of the intergrowth was found to be different from those of Bi₄Ti₃O₁₂ and SrBi₄Ti₄O₁₅. La³⁺ ions exhibit pronounced selectivity for the occupation of A site as La content is lower than 0.50, and tend to be incorporated into Bi₂O₂ layers when the La content is higher than 0.50. Lanthanum substitution brings about the structural phase transition in Bi₄Ti₃O₁₂-SrBi₄Ti₄O₁₅. The variation of ferroelectric property may be attributed to combined contribution from the decreasing of the oxygen vacancies, the relaxation of the lattice distortion, the destroying of the insulation and the space charge compensation effects of the Bi₂O₂ slabs.     

g-C3N4/CaTi2O5复合材料制备及其光催化性能

利用类石墨氮化碳（g-C₃N₄）和亚稳相钙钛氧化物（CaTi₂O₅）固相法制备C₃N₄/CaTi₂O₅复合材料。利用X射线衍射（XRD）、金相显微镜、扫描电子显微镜（SEM）及附带能谱分析仪（EDS）和N₂吸附-脱附对样品的显微结构和比表面积进行检测分析,并用紫外-可见吸收光度计（UV-Vis）测试了样品的光吸收性能,研究C₃N₄与CaTi₂O₅物质的量之比（n_C3N4/nCaTi₂O₅）对C₃N₄/CaTi₂O₅复合样品的物相结构和微观形貌的影响,同时考察C₃N₄/CaTi₂O₅复合样品在可见光照射下光催化降解罗丹明染料效果。实验结果表明：相比纯C₃N₄和CaTi₂O₅样品,C₃N₄/CaTi₂O₅复合样品在可见光下具有较高的光催化性能,随着n_C3N4/nCaTi₂O₅增加,样品的光催化降解率随之增加而后降低,当n_C3N4/nCaTi₂O₅=1：1时,样品的光催化降解率达到最大值99.5%,并且循环重复利用5次后,样品的光催化剂降解率仍几乎保持不变。复合样品光催化性能提高主要归因于复合能级结构有效地抑制了电子和空穴复合所致。     

g-C_3N_4/CaTi_2O_5复合材料制备及其光催化性能

利用类石墨氮化碳(g-C_3N_4)和亚稳相钙钛氧化物(CaTi_2O_5)固相法制备C_3N_4/CaTi_2O_5复合材料。利用X射线衍射(XRD)、金相显微镜、扫描电子显微镜(SEM)及附带能谱分析仪(EDS)和N2吸附-脱附对样品的显微结构和比表面积进行检测分析,并用紫外-可见吸收光度计(UV-Vis)测试了样品的光吸收性能,研究C_3N_4与CaTi_2O_5物质的量之比(nC_3N_4/nCaTi_2O_5)对C_3N_4/CaTi_2O_5复合样品的物相结构和微观形貌的影响,同时考察C_3N_4/CaTi_2O_5复合样品在可见光照射下光催化降解罗丹明染料效果。实验结果表明:相比纯C_3N_4和CaTi_2O_5样品,C_3N_4/CaTi_2O_5复合样品在可见光下具有较高的光催化性能,随着nC_3N_4/nCaTi_2O_5增加,样品的光催化降解率随之增加而后降低,当nC_3N_4/nCaTi_2O_5=1∶1时,样品的光催化降解率达到最大值99.5%,并且循环重复利用5次后,样品的光催化剂降解率仍几乎保持不变。复合样品光催化性能提高主要归因于复合能级结构有效地抑制了电子和空穴复合所致。     

Magnetic diphase nanostructure of ZnFe2O4/γ-Fe2O3

Magnetic diphase nanostructures of ZnFe₂O₄/γ-Fe₂O₃ were synthesized by a solvothermal method. The formation reactions were optimized by tuning the initial molar ratios of Fe/Zn. All samples were characterized by X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, and Raman spectra. It is found that when the initial molar ratio of Fe/Zn is larger than 2, a diphase magnetic nanostructure of ZnFe₂O₄/γ-Fe₂O₃ was formed, in which the presence of ZnFe₂O₄ enhanced the thermal stability of γ-Fe₂O₃. Further increasing the initial molar ratio of Fe/Zn larger than 6 destabilized the diphase nanostructure and yielded traces of secondary phase α-Fe₂O₃. The grain surfaces of diphase nanostructure exhibited a spin-glass-like structure. At room temperature, all diphase nanostructures are superparamagnetic with saturation magnetization being increased with γ-Fe₂O₃ content.