纳米SnO2的制备条件及其光催化活性

纳米粒子;光催化降解;纳米SnO2的制备条件及其光催化活性     

SO42-对TiO2及Ce-TiO2光催化性能的影响

采用溶胶-凝胶法制备了纳米SO42-/Ce-TiO2, SO42-/TiO2及Ce-TiO2光催化剂,并用IR, BET, XPS, XRD等手段对所制得的样品进行表征,将其用于对有机磷农药(DDVP)稀释液的光催化降解,结果表明所制SO42-/Ce-TiO2, SO42-/TiO2具有超强酸特征,其光催化活性较Ce-TiO2有明显提高.     

纳米SnO2@TiO2包覆催化剂的制备及表征

采用活性层包覆法在自制超细SnO     

醋酸和丙三醇对制备SrTiO3的影响

醋酸和丙三醇对制备ＳｒＴｉＯ_３的影响颜秀茹，霍明亮，王建萍，王菲，曾淑兰（天津大学化学系天津３０００７２）关键词　冰醋酸，溶胶－凝胶过程，丙三醇，ＳｒＴｉＯ_３ＳｒＴｉＯ３是电子材料中使用最广的材料之一，有关它的制备已有不少报道。一般可以通过ＳｒＣＯ...     

负载钛水合氧化物球状吸附剂的孔结构及其对氟离子吸附性能的研究

以大孔吸附树脂为基体，用Ｔｉ（ｎ－ＯＣ４Ｈ９）４浸渍基体树脂后．在一定条件下使该醇盐水解，制得由钛水合氧化物负载的球状吸附剂。本文研究了这种吸附剂的孔结构及其对氟离子的吸附性能。     

[Cr(NH3)6]3+离子在氨水中能直接形成吗?

通过实验事实和理论推算,说明在含有Cr~(3+)离子的溶液中加入NH_3·H_2O,主要生成的是Cr(OH)_3,而不是[Cr(NH_3)_6]~(3+)离子.     

用G~0-N图求歧化反应的平衡常数K

自由焓-氧化态图是以自由焓(G~0)为纵坐标、以氧化值(N)为横坐标所绘出的曲线图(简称G~0-N图)。例如,图1为锰的G~0-N图。这一图解用于说明元素的不同氧化态以及它们之间的氧化还原关系,在阐述单质、化合物在水溶液中进行氧化还原反应的过程中得到了广泛的应用。本文仅就应用此图判断歧化反应能否自发进行、计算歧化反应的平衡常数进行讨论,并纠正某些书刊中的一些错误。     

镧系元素掺杂Mn-Zn铁氧体的制备和研究

本文以Fe₂(SO₄)₃、ZnSO₄·7H₂O、MnSO₄·H₂O和Ln(NO₃)₃（Ln=La、Ce、Nd）为原料，通过水热合成法制备出了镧系元素（Ln=La、Ce、Nd）掺杂Mn-Zn铁氧体（Mn_0.6Zn_0.4Ln_xFe_2-xO₄）超细粉末，并利用XRD、TEM和VSM等手段对样品进行了表征，讨论了Ln掺杂量与掺杂种类对Mn-Zn铁氧体样品的影响。结果表明：要得到单相尖晶石型Mn_0.6Zn_0.4Ln_xFe_2-xO₄，Ln掺杂量（x）应小于0.1；适量Ln的掺杂可以大大改善Mn-Zn铁氧体的磁性能。     

纳米Mn-Zn铁氧体的制备和研究

Nanosize manganese zinc ferrites were fabricated by hydrothermal precipitation route using Fe₂(SO₄)₃, ZnSO₄·7H₂O, MnSO₄·H₂O as material, then some calcinated at 500 ℃ and studied by XRD, TEM, IR and VSM. The results showed that the products were spinel crystal structure and uniformly sized nanoparticles (15～25 nm) with little aggregation. The analysis of IR showed that the superficial water can be eliminated, but that was embedded in crystal lattice can not be removed by calcinating. The effect Zn content x on the lattice (a) of nanosize Mn_1-xZn_xFe₂O₄ was also discussed. The lattice of nanosize Mn_1-xZn_xFe₂O₄ decreases with x increasing; and its value deviated the standard lattice (a₀) of normal size manganese zinc ferrites. A lot of water was absorbed during the hydrothermal process owing to the large surface of nanosize particles. The change of magnetic properties of Mn_xZn_1-xFe₂O₄ with x increasing was studied: nanosize Mn_xZn_1-xFe₂O₄ particles synthesized by us exhibited peculiar magnetic properties curve with Zn content (x) increasing, Superparamagnetic behaviors of the synthesized ZnFe₂O₄ samples were confirmed by magnetic characterization, which can be explained by the difference between the distribution of the metal ions (Mn²⁺, Zn²⁺ and Fe³⁺) among the tetrahedral (A) and the octahedral (B) sites of nanosize ferrite and that of bulk ferrite.