掺杂稀土Nd的TiO2光催化法处理印染废水研究

以Ti(OBu)4、Nd2O3为原料,采用溶胶凝胶法,制备出纳米Nd2O3/TiO2光催化剂处理还原红染料溶液.讨论了Nd离子的掺杂量、催化剂用量、pH值以及光照时间等因素对降解率的影响.实验结果表明,掺杂了Nd的TiO2光催化剂对还原红降解率较高.     

Ag掺杂TiO_2催化降解活性印染废水

以钛酸四丁酯、硝酸银为原料,通过溶胶-凝胶(sol-gel)法制备了掺杂不同含量银的TiO2纳米粉体,并将其应用于活性染料—活性红195、活性黄145及活性蓝19的印染废水的光催化降解。结果表明:适量的银掺杂可有效提高TiO2对活性染料光催化降解活性;当pH为6~8、银掺杂量为0.6%(Ag/TiO2摩尔比)、活化温度为500℃、催化剂用量为0.1 g/L时,光催化降解效率最高,分别为92.5%(活性红195)、90.8%(活性黄145)、83.6%(活性蓝19)。     

人造沸石负载TiO_2光催化降解印染废水的研究

用溶胶-凝胶法制备了人造沸石负载TiO2的复合光催化剂,利用XRD对该催化剂进行了表征,并研究其对活性艳蓝降解率的影响。结果表明:光照时催化剂降解活性艳蓝的效果比无光照时要好。在一定的催化剂用量范围内,其降解率随催化剂用量的增大而增大,达到一定值后降解率变化不大;当活性艳蓝的浓度为100 mg/L、pH=5时,负载配比为1∶6的复合光催化剂,其粒度为60~80目、用量为1.5 g/L时,降解率可达96.3%。     

不同离子掺杂TiO_2薄膜及光催化活性研究

采用溶胶-凝胶法分别制备了掺杂Fe^3＋、Cu^2＋、Zn^2＋、Ce^3＋和La^3＋5种不同离子的纳米级TiO2薄膜,使用TiO2薄膜对亚甲基蓝溶液进行光催化试验。研究表明,在5种掺杂离子中,其La^3＋的掺杂效果最好,当La^3＋的适宜含量为1.8%（质量分数）时,掺杂与未掺杂的XRD图谱基本一致;掺入La^3＋离子使得TiO2的晶粒变小,可抑制晶相向金红石相转变;随着焙烧温度的升高TiO2晶粒逐渐变大,温度为700℃时,其粒径为27.6nm,TiO2为混合晶型（锐钛矿型和金红石型）,其活性最高。     

稀土掺杂ZnO光催化降解偏二甲肼废水研究

利用水热法制备稀土掺杂ZnO/La3+、ZnO/Ce3+、ZnO/Y3+纳米颗粒,用于光催化降解偏二甲肼废水。结果表明,掺杂ZnO颗粒大小均匀,直径在100～200 nm,纯度高。2 h后,对30 mg/L偏二甲肼废水的最大降解率分别为80.4%,82.3%,67.8%,降解率较纳米复合ZnO平均提高80%以上。     

稀土掺杂纳米TiO2光催化剂制备及其光催化性能

采用溶胶-微波法制备掺杂不同稀土元素纳米TiO2光催化剂,借助XRD和UV-Vis吸收光谱等手段对其进行表征.以甲基橙为模拟污染物,考察样品的光催化性能.结果表明,适量的La3+、Nd3+、Eu3+、Gd3+和Y3+掺杂可提高TiO2样品的光催化活性,最佳掺杂物质的量分数分别为0.1%、0.1%、0.3%、0.2%和0...     

Ag-N共掺杂TiO_2/膨润土光催化降解染料废水

采用溶胶-凝胶法制备了银氮共掺杂光催化剂Ag-N-Ti O2/膨润土,通过XRD和FTIR对其结构进行了表征,优化了该催化剂降解耐酸枣红染料废水的反应条件。结果表明,催化剂中有锐钛矿型Ti O2生成,部分Ti O2进入了膨润土层间,增大了其晶面层间距,并通过Ti—O—Si键实现了膨润土对Ti O2的固载;掺杂的Ag、N可能进入了Ti O2晶格,拓宽了其光谱响应范围,并提高了其光催化活性。当催化剂用量为2 g/L,溶液p H为3,光照时间为120 min,紫外光或可见光照射下,该催化剂对50 mg/L的耐酸枣红的降解率分别达到93.0%和89.3%,并在可见光下对其它3种50 mg/L的染料废水的降解率也达到了90%以上。     

Ag-N共掺杂TiO_2/膨润土光催化降解染料废水

采用溶胶-凝胶法制备了银氮共掺杂光催化剂Ag-N-Ti O2/膨润土,通过XRD和FTIR对其结构进行了表征,优化了该催化剂降解耐酸枣红染料废水的反应条件。结果表明,催化剂中有锐钛矿型Ti O2生成,部分Ti O2进入了膨润土层间,增大了其晶面层间距,并通过Ti—O—Si键实现了膨润土对Ti O2的固载;掺杂的Ag、N可能进入了Ti O2晶格,拓宽了其光谱响应范围,并提高了其光催化活性。当催化剂用量为2 g/L,溶液p H为3,光照时间为120 min,紫外光或可见光照射下,该催化剂对50 mg/L的耐酸枣红的降解率分别达到93.0%和89.3%,并在可见光下对其它3种50 mg/L的染料废水的降解率也达到了90%以上。     

氟掺杂纳米TiO_2粉体的合成及光催化活性研究

以钛酸四丁酯为前驱体,以三氟乙酸为掺杂剂,采用溶胶凝胶法于450℃煅烧2 h合成了F-掺杂的纳米TiO2粉体,利用XRD,XPS,EDS,BET等手段进行测试和表征,以次甲基蓝的降解评价其光催化活性。XPS测试表明,F-以掺入晶体中的F-和表面化学吸附F-2种形式存在。XRD及BET测试发现,设计摩尔比n(F)/n(Ti)=0.05时纳米粉体粒径由10.6 nm增大到12.9 nm,比表面积由110.3 m2/g降低到102 m2/g,但光催化活性提高,可将次甲基蓝1 h降解率由73.2%提高到83.1%,这是由于掺入F-后部分Ti4+形成Ti3+,Ti3+在TiO2的禁带间形成施主能级,更易吸收光生电子。     

过渡金属离子的掺杂对TiO2光催化活性的影响

考察了过渡金属离子对TiO2光催化性能的影响，结果发现：第二过渡系列金属离子对TiO2膜的修饰作用比第一过渡系列金属离子的修饰作用更加明显；第二，六副族的金属离子对TiO2膜的修饰效果较好，通过X射线衍射（XRD），电镜分析（SEM），光电能谱分析（XPS）及差热分析（DTA）对催化剂表面进行了表征，结果表明：TiO2的晶型为锐钛矿型，粒子半径为32．58nm。     

铜离子掺杂二氧化钛光催化板式微反应器

将微反应器技术应用于光催化反应是一项新兴且极具潜力的技术创新.采用金属蚀刻技术制造了板式微反应器,并通过溶胶-凝胶法在微反应器中负载了铜离子掺杂改性的TiO₂光催化剂涂层.使用X射线衍射分析、扫描电子显微镜以及紫外-可见漫反射吸收光谱对催化剂进行表征,并以甲基橙的降解反应来评价微反应器的光催化效果.结果表明,铜离子掺杂能够有效提高微反应器的光催化性能,掺杂浓度为0.04%(摩尔比于Ti)时效果最优,能够在90 s的停留时间内使初始浓度为10 mg·L^-1的甲基橙溶液降解45%;光催化微反应器中甲基橙的降解过程为不完全氧化的动力学一级反应,其反应速率常数(k)远高于常规反应器体系,并随着甲基橙溶液初始浓度(C₀)的减小而增大,且lnk-lnC₀具有良好的线性关系.     

钒掺杂二氧化钛光催化活性研究

二氧化钛凭借优异的光催化性能,越来越受到人们的广泛关注和重视。以钛酸四丁酯为原料,利用水解-水热-干燥/煅烧工艺制备得到未掺杂TiO₂光催化剂和掺钒TiO₂光催化剂,利用其对甲基橙溶液的降解率做了比较分析。结果表明,以钛酸四丁酯为原料,采用溶胶-凝胶法制备钒掺杂TiO₂光催化剂是可行的。制备V/TiO₂产品的最佳工艺条件：钒钛质量比为6∶100、水热温度为160 ℃、水热时间为12 h,120 ℃下干燥14 h。紫外光照射条件下,甲基橙光催化降解效率达到99.10%,降解时间小于45 min。     

Photocatalytic activities of electrospun tin oxide doped titanium dioxide nanofibers

SnO₂ doped TiO₂ electropsun nanofiber photocatalysts were successfully prepared by means of electrospinning process. The surface morphology, structure and optical properties of the resultant products were characterized by field-emission electron microscopy (FE-SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy, photoluminescence (PL) and cathodoluminescence (CL) techniques. The utilized physiochemical analyses indicated that the introduced SnO₂ doped TiO₂ nanofibers have a smooth surface and uniform diameters along their lengths. The photocatalytic performance of the composite nanofibers was tested for degradation of methylene blue (MB) and methyl orange (MO) dye solution under ultraviolet (UV) irradiation. Under the UV irradiation, the photocatalytic reaction rate in case of utilizing SnO₂-doped TiO₂ nanofibers was rapidly increased than that of the pristine TiO₂ nanofibers. Overall, this study demonstrates cheap, stable and effective material for photocatalytic degradation at room temperature.     

氮掺杂二氧化钛光催化降解超纯净水中有机化合物

UV氧化单元是生产超纯水过程中的一个重要组成部分。然而,常规UV氧化能耗大,寻求高效节能的UV氧化方式已成为当今超纯净水净化研究热点之一。文中采用溶胶凝胶法,以钛酸四丁酯为钛前驱体,乙醇为溶剂,成功制备了TiO2薄膜。TiO2薄膜在加温条件下氨化制得了含氮TiO2。实验通过光催化降解超纯净水中乙二醇、异丙醇及尿素,考查了合成催化剂的性能。实验表明:在相同紫外光源条件下,掺氮TiO2的催化效果明显优于TiO2的催化效果。将掺氮TiO2与254 nm UV灯结合使用能达到与仅使用185 nm UV灯的同样的氧化效果,将此技术应用于超纯净水处理将会大大降低清洁水净化能量消耗及生产成本。     

Photocatalytic and photoelectrochemical performance of crystallized titanium dioxide sol with neodymium ion modification

Titanium dioxide was modified with neodymium metal ion by a wet‐chemical coprecipitation–peptization technique under low temperature to produce crystallized sol catalyst (Nd³⁺? TiO₂). Crystal structure was characterized by X‐ray diffraction measurement. Sol particle size was studied by means of particle size distribution measurement. Surface hydroxyl groups were determined using Fourier transform infrared spectroscopy. Photocatalytic reactivity of sol photocatalysts was investigated under ultraviolet and visible light irradiation. Photodegradation and photomineralization under ultraviolet and visible light excitation were studied in the TiO₂ and Nd³⁺? TiO₂ hydrosol reaction system. A photocurrent–time spectrum was also applied to characterize the electron‐transferring efficiency in the process of self‐sensitization and dye‐sensitization photocatalysis reactions. As an application approach of sol catalyst, Nd³⁺? TiO₂ sol was coated on a diffusing optical fibers bundle and the photocatalytic reaction was investigated in the immobilization fiber reactor. Copyright © 2005 Society of Chemical Industry     

Photocatalytic degradation of methyl orange using polythiophene/titanium dioxide composites

Polythiophene/titanium dioxide (PT/TiO₂) composites were prepared via in situ chemical oxidative polymerization, and the obtained composites were characterized by X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–Vis) diffuse reflectance spectroscopy (DRS) and transmission electron microscopy (TEM). Using methyl orange (MeO) as a target pollutant, the adsorption capacities and the photocatalytic activities of the resulting composites were investigated. The results indicate that PT/TiO₂ composites have good adsorption capacities due to the electrostatic attraction between the positively charged composite particles’ surfaces and MeO; the incorporation of PT into the composites enhances the photocatalytic degradation activity for MeO under both UV and visible light.     

二氧化钛光催化降解硝基苯废水

用紫外灯作为光源,以锐钛型TiO2为催化剂降解硝基苯。探讨了光照时间、初始pH值、初始浓度、催化剂用量和载铜TiO2复合催化剂对光催化降解的影响。结果表明,TiO2用量为3.0 g/L,pH为3,硝基苯初始浓度为40.6 mg/L,室温条件下,光照6 h硝基苯降解率为80.6%;掺杂1%Cu2+(摩尔分数)的TiO2复合催化剂,光催化活性高于纯TiO2,其光催化降解率较TiO2提高14.5%。     

二氧化钛悬浆体系光催化降解4BS染料的研究

以高压汞灯为光源,在TiO2粉末悬浮体系内,初步研究了水溶液中直接耐酸大红4BS染料的半导体光催化降解及各种影响因素。研究结果表明,4BS染料在pH为3．5左右时降解较为适宜,4BS染料脱 随时间的变化呈现先快后慢的趋势,染料初始浓度对脱色率的影响符合线性递减的规律,适宜的催化剂用量应略大于1．5g/L。     

Photocatalytic activity of fluorine-doped titanium dioxide

Fluorine-doped anatase has a higher photocatalytic activity compared to undoped anatase obtained under identical conditions and retains this activity after thermal treatment in a temperature range of 400–700°C. The photocatalytic activity of the evaluated fluorine-doped titanium oxohydroxide with an allowance for its titanium content is insignificantly lower than the photocatalytic activity of fluorine-doped anatase.     

纳米TiO_2光催化氧化处理糠醛废水的研究

以钛酸丁酯为原料,采用溶胶凝胶法制备的TiO_2被用于处理糠醛废水.研究结果表明:pH=2～6的150 mL废水中加入0.06 g TiO_2和3 mL ClO_2或H_2O_2,在不断搅拌下,紫外光照65 min,COD去除率可达到67%.此光催化氧化反应分两个阶段,均符合一级反应动力学规律:R=1.391 2t(t=0～30min).R=0.4349t+29.342(t=30～75 min).而且TiO_2催化剂重复使用15次的光催化效果没有变化,为TiO_2光催化氧化处理糠醛废水工业化应用提供了技术支撑.