Ti基系列阳极的制备及电解染料废水实验研究

采用热氧化法制备了Ti／PbO2、Ti／SnO2-Sb2O3／PbO2、Ti／SnO2-Sb2O3／PbO2-Cu、Ti／SnO2-Sb2O3／PbO2-Ni和Ti／SnO2-Sb2O3／PbO2-Fe5种钛基系列阳极,进行电催化氧化处理模拟染料废水酸性品红溶液的实验研究,比较了不同电极的处理效率、反应速率,同时分析了酸性品红降解过程。结果表明：相对于Ti／PbO2和Ti／SnO2—Sb2O3／PbO2阳极,金属掺杂改性电极Ti／SnO2-Sb2O3／PbO2-Fe和Ti／SnO2-Sb2O3／PbO2-Ni对酸性品红有着更好的去除效率和降解速率,而Cu掺杂电极Ti／SnO2-Sb2O3／PbO2-Cu改性效果不明显。5种电极的电催化氧化过程均符合一级动力学模型。酸性品红在Ti／SnO2-Sb2O3／PbO2-Fe阳极上电催化氧化降解过程的紫外-可见光谱图表明在电流密度75mA／cm^2、电解质Na2SO4浓度12g／L的条件下,处理100mg／L的酸性品红模拟废水,60min内其特征吸收峰消失,酸性品红基本去除,但同时生成了部分小分子中间产物。     

钛基二氧化铅电极的制备及在电合成4-吡啶甲酸中的应用

钛基二氧化铅电极 (Ti/PbO2 )具有较好的耐腐蚀性和导电性 ,析氧过电位高且硬度大 ,是一种理想的不溶性阳极材料。该电极由半导体中间层和电沉积的二氧化铅组成 ,经过实验获得了最佳的电极制备参数。中间层Sb2 O3 的质量分数为 15 %～ 2 5 % ,电沉积液中的添加剂NaF可使PbO2 镀层致密 ,浓度为 0 .4mg/L ,pH值为 1～2 ,电流密度为 5 0mA/cm2 。将该钛基二氧化铅电极应用到电解氧化 4-甲基吡啶合成 4-吡啶甲酸的实验中 ,以反应的转化率、电流效率和电极的腐蚀速度为依据 ,考察了电极的活性、镀层的质量和电极寿命 ,并通过极化曲线评价了电极的导电性及X -衍射光谱表征了二氧化铅的晶型为 β-PbO2     

钛基二氧化铅电极的制备及在电合成4—吡啶甲酸中的应用

钛基二氧化铅电极（Ti/PbO2)具有较好的耐腐蚀性和导电性，析氧过电位高且硬度大，是一种理想的不溶性阳极材料，该电极由半导体中间层和电沉积的二氧化铅组成，经过实验获得了最佳的电极制备参数，中间层Sb2O3的质量分数为15％－25％，电沉积液中的添加剂NaF可使PbO2镀层致密，浓度为0．4mg/L,pH值为1－2，电流密度为50mA/cm^2，将该钛基二氧化铅电极应用到电解氧化4－甲基吡啶合成4－吡啶甲酸的实验中，以反应的转化率，电流效率和电极的腐蚀速度为依据，考察了电极的活性，镀层的质量和电极寿命，并通过极化曲线评价了电极的导电性及X－衍射光谱表征了二氧化铅的晶型为β-PbO2。     

修饰石墨基二氧化铅电极电催化氧化降解苯胺

选择石墨作为基体,采用电沉积的方法制备出掺杂镧元素修饰的二氧化铅电极.通过对该电极进行XRD和SEM测试,发现电极的表面主要成分为β-PbO₂,底层为α-PbO₂;镧金属的氧化物嵌入到PbO₂晶格当中,使晶形发生显著改变;电极表面致密均匀,空隙率大,利于对目标有机物吸附和发生电催化氧化反应.以该修饰电极为阳极,石墨电极为阴极,对苯胺模拟废水进行电催化氧化处理,分别考察了阴离子种类、电流密度、进水质量浓度、反应初始pH值对苯胺和COD去除率的单因素影响.该修饰二氧化铅电极对苯胺的电化学氧化降解反应基本符合一级反应动力学规律.     

Ce-N-TiO2/AC光催化剂催化氧化染料废水试验

目的 考察制备的Ce-N-TiO2/AC光催化剂对有机染料废水的处理效果,确定其去除甲基橙染料废水的工艺条件.方法 在自制光催化反应器中,利用制备的Ce-N-TiO2/AC光催化剂在紫外灯的条件下处理染料废水,分析对比在不同因素条件下对染料废水的降解率.结果 Ce-N-TiO2/AC光催化剂对染料废水具有较高的脱色率.在适宜条件:染料废水质量浓度为40 mg/L,初始pH =4.0,光催化剂投加量为4g/L,Ce4掺杂质量分数为2.0％、N掺杂质量分数为1.3％,反应时间210 min,染料废水的脱色率可达86.6％,复用次数达5次.结论 制备Ce4+和N共掺杂改性后的光催化剂,具有较高的重复利用率,相比单掺杂光催化剂,提高光催化能力效果明显.     

Co改性PbO2/Ti电催化电极处理模拟染料废水

以脱色率为考察指标,研究了自制Co改性PbO2/Ti电催化电极处理亮绿、结晶紫和甲基橙3种模拟染料废水的最佳条件:控制电流分别为0.30、0.30、0.15 A,处理7、7、9 min,加入电解质NaCl 0.5、0.7、0.5 g。动力学实验结果表明:亮绿和甲基橙的降解过程符合一级反应动力学关系,结晶紫符合零级反应动力学关系。紫外分光光度法测试结果表明:3种染料分子在电解催化过程中生色基团被破坏,发生了降解,揭示了Co改性PbO2/Ti电催化电极降解机理。     

难降解有机物对硝基苯酚的电化学氧化工艺研究

研究了难降解有机物对硝基苯酚的电化学氧化的电解工艺和降解机理 实验结果表明 :在碱性条件 (pH =10 )下 ,以自制PbO2 为阳极 ,电极面积为 1cm2 ,,保持电流密度 30mA/cm2 电解 134min ,2 0 0mL对硝基苯酚溶液 ,浓度从 2 0 0mg/L降低到 1mg/L以下 ,COD去除率 10 % ,BOD/COD值达到0 .6 3 这种工艺操作简单 ,且无二次污染     

二氧化氯催化氧化处理萘酚绿模拟废水的实验研究

研究了利用二氧化氯直接氧化和催化氧化处理萘酚绿模拟废水，单纯用二氧化氯化学氧化处理COD为1533?mg/L的萘酚绿废水时，最佳pH值为1.2，二氧化氯投加量为1500?mg/L，反应60?min，COD去除率为45.3%，BOD5去除率为11.2%，脱色率为92.5%.在最佳pH值为1.2，经过1500?mg/L二氧化氯和0.25?g TiO2催化氧化60?min后，COD去除率为52.5%，BOD5去除率为48.1%，脱色率为96.4%.结果表明，萘酚绿经化学氧化和催化氧化后，分子中萘环被氧化降解为羧酸和萘醌，并进一步降解为无机物，提高了废水的可生化性，为难降解废水的后续处理创造了条件.     

Cu~(2+)/Ce~(4+)-TiO_2可见光催化降解活性艳红X-3B

采用溶胶凝胶法合成了掺杂Cu~(2+)和Ce~(4+)的Ti O2可见光催化剂,用活性艳红X-3B降解脱色为模型反应,结合紫外-可见光谱法、XRD和SEM等表征手段,考察了制备条件与光催化活性的关系.实验结果表明:适量掺杂稀土元素Ce~(4+)较单独掺杂Cu~(2+)能更加有效地提高催化剂在可见光下的催化活性,掺杂后使催化剂的吸收带边位置发生红移,晶型结构为锐钛矿和金红石的混合晶型.掺杂Ce~(4+)量为1.5%时,0.4 g催化剂对30 m L浓度为5 mg/L的活性艳红X-3B模拟印染废水降解率达到61.1%.     

二氧化氯催化氧化处理萘酚绿模拟废水的实验研究

研究了利用二氧化氯直接氧化和催化氧化处理萘酚绿模拟废水，单纯用二氧化氯化学氧化处理COD为1533mg／L的萘酚绿废水时，最佳pH值为1．2，二氧化氯投加量为1500mg／L，反应60min，COD去除率为45.3％，BOD5去除率为11．2％，脱色率为92．5％．在最佳pH值为1．2，经过1500mg/L二氧化氯和0．25g TiO2催化氧化60min后，COD去除率为52．5％，BOD5去除率为48．1％，脱色率为96．4％．结果表明，萘酚绿经化学氧化和催化氧化后，分子中萘环被氧化降解为羧酸和萘醌，并进一步降解为无机物，提高了废水的可生化性，为难降解废水的后续处理创造了条件．     

SnO2及SnO2／Fe2O3复合微米材料的合成及表征

本文首先以SnCl2·2H2O为主要原料,无水乙醇为溶剂,利用溶剂热法于180℃反应24h得到了SnO2微球;再以所制备的SnO2微球为前驱体,FeCl3·6H2O为主要原料,通过水热法得到SnO2／Fe2O3复合材料．利用X射线粉末衍射仪（XRD）和扫描电子显微镜（SEM）对所得产物进行了表征．结果表明：所得的SnO2为四方锡石型,形貌为微球,平均直径约为2．0μm;复合后得到的SnO2／Fe2O3微球平均直径约为2．5μm．其中,Fe2O3为六方赤铁矿型,在复合物的表面以小颗粒的形式存在,尺寸约为200nm．另外,也对SnO3与SnO2／Fe2O3微球的形成过程进行了讨论．     

Temperature dependence on reaction of CaCO3 and SO2 in O2/CO2 coal combustion

The temperature dependence on the reaction of desulfurization reagent CaCO₃ and SO₂ in O₂/CO₂ coal combustion was investigated by thermogravimetric analysis, X-ray diffraction measurement and pore structure analysis. The results show that the conversion of the reaction of CaCO₃ and SO₂ in air is higher at 500–1 100 °C and lower at 1 200 °C compared with that in O₂/CO₂ atmosphere. The conversion can be increased by increasing the concentration of SO₂, which causes the inhibition of CaSO₄ decomposition and shifting of the reaction equilibrium toward the products. XRD analysis of the product shows that the reaction mechanism of CaCO₃ and SO₂ differs with temperature in O₂/CO₂ atmosphere, i.e. CaCO₃ directly reacts with SO₂ at 500 °C and CaO from CaCO₃ decomposition reacts with SO₂ at 1 000 °C. The pore analysis of the products indicates that the maximum specific surface area of the products accounts for the highest conversion at 1 100 °C in O₂/CO₂ atmosphere. The results reveal that the effect of the atmosphere on the conversion is temperature dependence.     

Preparation of TiO2 photocatalyst loaded with V2O5 for O2 evolution

TiO₂ photocatalysts loaded with V₂O₅ were prepared via a modified hydrolysis process, and characterized by X-ray diffraction, transmission electron microscopy, Raman spectra and diffuse reflectance UV-Vis spectra measurements. The photocatalytic activity of V₂O₅/TiO₂ was investigated by employing splitting of water for O₂ evolution. The results indicate that V₂O₅ loading can pronouncedly improve the photocatalytic activity of TiO₂ with Fe³⁺ as an electron acceptor under UV or visible light irradiation. The optimum mass fraction of the loaded V₂O₅ is 8%, and the largest speed of O₂ evolution for 8%V₂O₅ (mass fraction) loaded TiO₂ catalyst is 118.2 μmol/(L·h) under UV irradiation, and 83.7 μmol/(L·h) under visible light irradiation.     

Modification of nano-TiO2 by Al2O3 in-situ coating

A novel technology of in-situ coating Al₂O₃ on the surface of H₄TiO₄ was developed to prevent the aggregation of nano-TiO₂ powders and improve the dispersibility and thermal stability in the way of forming a uniform coating layer. The heterogeneous nucleation was conducted to prepare the precursor of nano-TiO₂ and then Al₂O₃ was coated on the surface of precursor. The effects of Al₂O₃ in-situ coating on the properties of nano-TiO₂ were investigated. The results show that H₄TiO₄ can be dispersed well under alkaline condition (pH 8.5) and the heterogeneous nucleation can be controlled easily. The optimized uniform coating layer is obtained by adding 5% (mass fraction) and 10% of Al₂O₃ and the aggregation of nano-TiO₂ powders is effectively inhibited and the dispersibility is obviously improved. The crystal sizes of TiO₂ powders are 12.3, 11.4 and 8.7 nm after coating 0,5% and 10% of Al₂O₃ respectively. Al₂O₃ on the surface of particulates in amorphous phase could increase the thermal stability of nano-particles after calcined at 550 °C. Foundation item: Project(04GK2007) supported by Hunan Industrial Key Project of Science and Technology     

氢（氘、氚）分子与低能氦原子（E=0.1eV）碰撞研究

对H2,D2,T2碰撞体系,采用Tang-Toennies势,用密耦方法求解散射方程,计算了E＝0.1eV时00－00,00－02,00－04分子转动激发分截面和角分布,并研究了原子与分子碰撞弹性分波截面和非弹性激发截面随量子数增加的变化规律。     

Bi2O3和Fe2O3掺杂对BaTiO3陶瓷显微结构的影响

利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线能量色散谱(EDAX)等结构分析技术,研究了施主(Bi     

三氧化二铝是导致建筑物火灾的严重隐患

建筑物供电线路中的铜线与铝线连接处常常生成一种灰白物质－－三氧化二铝,极易引发建筑物火灾。着重介绍和分析这种灰白物质的成分、生成原因、危害以及防止其生成的主要措施。     

Characteristics of LiCoO2, LiMn2O4 and LiNi0.45Co0.1Mn0.45O2 as cathodes of lithium ion batteries

LiNi_0.45Co_0.10Mn_0.45O₂ was synthesized from Li₂CO₃ and a triple oxide of nickel, cobalt and manganese at 950 °C in air. The structures and characteristics of LiNi_0.45Co_0.10Mn_0.45O₂, LiCoO₂ and LiMn₂O₄ were investigated by XRD, SEM and electrochemical measurements. The results show that LiNi_0.45Co_0.10Mn_0.45O₂ has a layered structure with hexagonal lattice. The commercial LiCoO₂ has sphere-like appearance and smooth surfaces, while the LiMn₂O₄ and LiNi_0.45Co_0.10Mn_0.45O₂ consist of cornered and uneven particles. LiNi_0.45Co_0.10Mn_0.45O₂ has a large discharge capacity of 140.9 mA · h/g in practical lithium ion battery, which is 33.4% and 2.8% above that of LiMn₂O₄ and LiCoO₂, respectively. LiCoO₂ and LiMn₂O₄ have higher discharge voltage and better rate-capability than LiNi_0.45Co_0.10Mn_0.45O₂. All the three cathodes have excellent cycling performance with capacity retention of above 89.3% at the 250th cycle. Batteries with LiMn₂O₄ or LiNi_0.45Co_0.10Mn_0.45O₂ cathodes show better safety performance under abusive conditions than those with LiCoO₂ cathodes. Foundation item: Project(50302016) supported by the National Natural Science Foundation of China; Project(2005037698) supported by the Postdoctoral Science Foundation of China     

Influence of ZrO2 on sintering and crystallization of CaO-Al2O3-SiO2 glass-ceramics

ZrO2 was added into CaO-Al2O3-SiO2 glass-ceramics and the effect of ZrO2 on sintering and crystallization of CaO-Al2O3-SiO2 glass ceramics was investigated. The results show that the sintering shrinkage ratio of glass particles decreases with the increase of the content of ZrO2. ZrO2 has an unfavourable effect on sintering shrinkage ratio of glass particles. The sintering shrinkage ratio of glass particles increases with the increase of sintering temperature. The increase of sintering temperature favors the decrease of the liquid phase viscosity of glass particles. ZrO2 has little effect on crystallization of main crystalline phase （β-wollastonite）. However, it promotes the crystallization at relatively low temperature.     

Preparation and crystallization action of SiO2 -Al2O3 -CaO-ZnO-R2O porous glass-ceramics

Using powder-sintering method,SiO2-Al2O3-CaO-ZnO-R2O porous glass-ceramics were produced for analysis. Five samples with different SiO2 /CaO ratios were used in the research. The mechanical properties, microstructures and textures of porous glass-ceramics are investigated by using differential thermogravimetric analysis/differential thermal analysis ( TGA/SDTA) ,X-ray diffraction ( XRD) ,and scanning electron microsco- py ( SEM) . The activity energy of crystallization ( E) and crystallization kinetics parameter ( k) were calculated based on the modified JMA equation. The Avrami parameter n was obtained according to Augis-Bennett function. The results show that the k value of No. 1 sample ( SiO2 /CaO = 61∶ 18) is the largest among all samples, which tends to crystallize more easily,and crystallization processes of all samples are observed bulk crystallization. The main crystal phase observed is parawollastonite ( clinorhombic system) with puncheon shape. Poreforming agents decomposed at 100 - 500 ℃ form a large number of closed pores with micron dimension and several semi-open pores distribute uniformly in the glass-ceramics matrix. This work may be expected to be favorable for industrial scale applications of porous glass-ceramics in the field of building thermal insulation.