以膨胀珍珠岩为载体的漂浮型TiO2光催化剂降解水面浮油

以膨胀珍珠岩为载体制备了漂浮负载型TiO     

纳米TiO2混晶的形成及其对光催化性能的影响

用溶胶-凝胶法通过改变晶型调节剂2-甲基-2,4戊二醇的添加量制备了金红石相和锐钛矿相比例不同的纳米TiO2混晶.以膨胀珍珠岩为载体,制备珍珠岩负载纳米TiO2混晶催化剂,以X射线衍射(XRD)、紫外-可见吸收光谱(UV-visiblespectrum)、BET、Raman光谱等方法对纳米TiO2混晶和负载型纳米TiO2催化剂进行表征和性能测定,研究了催化剂的混晶效应对光催化降解甲基橙催化性能的影响.结果表明:晶型调节剂的含量及制备条件对混晶中金红石和锐钛矿相TiO2的比率有较大的影响.对于负载型纳米TiO2催化剂,混晶比影响催化剂的光催化降解效率,当混晶比为6.1时光催化效率最高,这一结果对光催化剂的制备和应用都具有重要的意义.     

载体对负载型TiO2催化剂光催化性能的影响

 以活性碳（AC）和镁铝尖晶石（MA）为载体，采用真空吸附水解法制备了负载型光催化剂TiO2／AC和TiO2／MA，并采用TiO2溶胶负载法制备了活性碳负载催化剂TiO2（C）／AC．以氯仿为探针分子研究了其在催化剂上的吸附及光催化降解反应性能．结果表明，催化剂的制备方法、TiO2负载量与载体的吸附性能对光催化活性有明显的影响．通过优化制备条件，TiO2／AC催化剂的催化活性可提高到纳米TiO2的2．5倍．氯仿在AC上的饱和吸附量较高，但吸附强度较弱；在纳米TiO2上的吸附情况则正好相反．氯仿在AC和TiO2上吸附性质的差异有利于吸附在TiO2／AC上的氯仿分子从活性碳载体向TiO2光催化活性中心迁移．镁铝尖晶石载体对光催化反应没有明显的促进作用，与其基本上不吸附氯仿分子有关．与TiO2胶体负载法相比，真空吸附水解法是一种较好的负载型TiO2光催化剂制备方法．     

SiO2负载的TiO2光催化剂可见光催化降解染料污染物

 采用酸催化溶胶-凝胶法制备了SiO2负载的TiO2光催化剂,考察了制备条件对负载型TiO2光催化剂的晶相、结构、比表面积和可见光催化活性的影响. 结果表明,采用SiO2为载体时,TiO2以纳米颗粒的形态分散在载体表面,负载型TiO2/SiO2催化剂的比表面积大、等电点低而且热稳定性能良好. 偶氮染料酸性橙7的可见光催化降解实验结果表明,染料污染物在催化剂表面的吸附是影响催化剂可见光催化活性的重要因素. 与试剂TiO2样品相比,负载型TiO2/SiO2光催化剂具有更好的光催化活性和沉降性能.     

以偏钛酸为原料制备高效负载型纳米TiO2/活性炭光催化剂

以颗粒活性炭(AC)为载体, 偏钛酸为钛源, 采用浸渍-水热法制备负载型TiO2光催化剂, 在300～800 ℃下热解处理. 利用X射线衍射、扫描电镜、拉曼光谱和氮气吸附对催化剂样品进行了表征. 以甲基橙(MO)降解为模型反应, 对负载型TiO2光催化性能进行评价. 结果表明, 经600 ℃焙烧的样品具有最佳光催化性能, 为锐钛矿晶型, 负载于活性炭上的TiO2是由30～50 nm的球型颗粒组成. 负载型TiO2/AC光催化剂的光催化活性高于相同方法制备TiO2和AC混合物及商业化产品Degussa P25与活性炭混合物, 光降解反应符合一级反应动力学方程. 催化剂重复使用5次其光催化活性基本保持不变.     

水面石油污染物的光催化降解

制备了漂浮负载型ＴｉＯ２光催化剂,并用ＸＲＤ,ＢＥＴ,ＴＥＭ和ＳＥＭ等方法进行了表征。研究了这类催化剂对水面石油污染物的光催化降解,实验结果表明,掺杂Ｆｅ＾３＋的ＴｉＯ２光催化剂具有高的光催化活性,经高压汞灯照射８ｈ,水面原油降解７５％。     

H4SiW12O40/TiO2/SiO2复合光催化剂的制备及性能研究

溶胶-凝胶法制备了TiO2/S iO2光催化剂,利用所得TiO2/S iO2光催化剂为基体,浸渍烧结法制备了H4S iW12O40/TiO2/S iO2表面负载修饰型复合光催化剂。TG-DSC、XRD、SEM、BET对催化剂的物化结构进行了表征,分析了TiO2和H4S iW12O40催化活性组分在S iO2载体表面上的键联机理。光催化性能测试是以低浓度酸性品红染料的水溶液为降解目标物,试验结果表明H4S iW12O40的负载修饰可以改进TiO2/S iO2光催化剂的催化活性,酸性品红的降解效率最高可以增加45%。     

TiO2/AC复合催化剂光催化降解气相1,2-二氯苯

以商品活性炭(AC)为载体, 采用溶胶-凝胶法制备不同比表面积和TiO2负载量不同的光催化剂(TiO2/AC). 用氮吸附、X射线衍射(XRD)、扫描电子显微镜(SEM)等表征方法, 获得了所制备的TiO2/AC性能参数; 并通过降解气相1,2-二氯苯(1,2-DCBz)的实验研究了TiO2/AC催化剂的光催化氧化性能, 主要考察参数包括催化剂使用量、比表面积、气相1,2-DCBz浓度等对光催化氧化的影响. 结果表明: 负载于AC上的TiO2颗粒粒径为10 nm左右, TiO2颗粒负载在大比表面积的载体AC上有利于光催化降解气相1,2-DCBz. 通过比较商用P25和自制TiO2/AC光催化剂对气相1,2-DCBz的降解效果, 证明了AC吸附作用和TiO2光催化降解的协同作用使TiO2/AC光催化剂对气相1,2-DCBz的降解效率有较显著的提高.     

La2O3掺杂TiO2光催化剂的制备和性能

采用溶胶-凝胶法制备了La2O3掺杂TiO2纳米光催化剂，并通过XRD、TEM、BET和XPS等手段进行了表征．掺入La2O3后，阻止了TiO2从锐钛矿晶型向金红石晶型的转变，使TiO2的粒径减小，比表面积增大．以甲基橙为光催化降解反应模型化合物，考察了光催化剂的活性．测定了甲基橙在纯TiO2和La2O3掺杂TiO2光催化剂上的吸附常数．考察了pH、H2O2对降解性能的影响．讨论了光催化活性与催化剂性质的关系．     

WO3-TiO2薄膜型复合光催化剂的制备和性能

 采用溶胶－凝胶法在多孔钛片上制备了WO3－TiO2薄膜型复合光催化剂,并用甲基橙的光催化降解反应对所得薄膜型催化剂的活性进行了评价．实验结果表明：x（W）＝0．5％,涂覆层数为3层,在500℃焙烧1h的WO3－TiO2薄膜型光催化剂的活性最高,比纯TiO2薄膜高出96．7％．此时多孔钛片上负载的TiO2以锐钛矿和金红石两种晶形存在,表明适量W的掺入可使TiO2的相转变温度显著降低．     

PREPRARATION OF CoPcS/TiO2/BEADS AND THEIR PHOTOCATALYTIC REACTIVITY FOR PHOTODEGRADATION OF VEGETABLE OIL FLOATING ON WATER

The paper introduces the preparation of floating TiO2/beads photocalyst attached to the hollow glass micro-beads surface by sol-gel technique using tetrabutyl titanate as material and the preparation of floating CoPcS/TiO2/beads by dip-coatig technique. The optimal factor of degradation of vegetable oil floating on water using CoPcS/TiO2/beads was studied. The result showed that the removal rate of vegetable oil floating on water can highly reach 90% at the optimal condition （acidity or neutrality, 375W medium-pressure mercury vapour lamp, illumination 2h-3h, lg CoPcS/TiO2/beads）. The photocatalytic removal efficiency causing by CoPcS/TiO2/beads was increased rapidly by adding a trace amount of H2O2.     

球磨法制备复合光催化剂Bi12TiO20/ZnO及其光催化性能

本文用水作为分散介质,采用球磨法掺杂一定量的Bi₁₂TiO₂₀于ZnO中制备复合光催化剂Bi₁₂TiO₂₀/ZnO. 利用UV-Vis、XRD和SEM等仪器对样品进行了分析与表征. 通过对甲基橙的氧化来研究其光催化活性. 结果表明,光催化剂Bi₁₂TiO₂₀/ZnO对甲基橙氧化的催化活性高于氧化锌的催化活性.当Bi₁₂TiO₂₀的掺杂量为0.5%(质量分数),球磨时间为12 h,焙烧温度为300℃时,光照20 min后,复合光催化剂Bi₁₂TiO₂₀/ZnO对甲基橙的降解率可达到95.2%.     

可磁分离的氮掺杂二氧化钛光催化剂的制备及光催化性能

将氮掺杂二氧化钛和通过液相催化相转化制备的磁性载体混合、煅烧制备了一种可磁分离的光催化剂TiO2-xNx/SiO2/NiFe2O4(TSN), 这种光催化剂显示出了典型的铁磁性和可见光活性(λ>400 nm). 对该光催化剂的XRD谱图和透射电镜照片进行分析. 结果表明, SiO2/NiFe2O4(SN)纳米粒子黏附在TiO2-xNx聚集体的表面形成了TSN复合光催化剂. 利用光催化降解甲基橙的效果来评价这种光催化剂的活性. 结果表明, 在NiFe2O4和TiO2-xNx之间包覆一层无定形的SiO2, 可以显著地提高催化剂的脱色效果.     

Effect of titanium dioxide on photostability of solid-state mequitazine

TiO(2) has been widely used in pharmaceutical products, and it also has been used as a photocatalyst. In this study, the influence of photocatalytic activity on the stability of solid-state mequitazine, an H(1)-blocker, was investigated. The photo-degradation of mequitazine with TiO(2) occurred under irradiation with both light sources. The degree of degradation of mequitazine with anatase was higher than that of rutile. The degradation was significantly enhanced with increasing relative humidity. The relationship between the apparent degradation rate constant and water vapor pressure could be clearly described by a simple power law. The major photo-degradation products of mequitazine, resulting from photocatalytic activity of TiO(2), were mequitazine-S-oxide and mequitazine-sulphone. A remarkable degradation of mequitadine occurred with addition of TiO(2), and its photocatalytic activity was controlled by water vapor pressure. The photo-degradation of mequitazine with TiO(2) is a different process from mequitazine without TiO(2), because mequitazine-S-oxide and mequitazine-sulphone are not formed with normal photo-degradation of mequitazine.     

TiO2/CuS异质结的制备及光催化降解染料废水的研究

以原位沉淀法和水热法混合的合成手段,制备了TiO_2/CuS异质结光催化剂。这种异质结改善了单一TiO_2半导体光催化剂的缺陷,明显提高了太阳光下光催化降解甲基橙的效率。TiO_2与CuS之间形成的异质结结构和合适的能带结构能够扩展材料对太阳光谱的响应范围并且很好地收集和传输光诱导载流子,从而提高了载流子的分离效率,最终使半导体的光催化活性明显增强。结果表明,太阳光照射25min后,相比于TiO_2/MnS、TiO_2/CdS和TiO_2/ZnS异质结,TiO_2/CuS异质结(TiO_2和CuS的摩尔比为3∶1)对甲基橙的降解效果最佳,降解效率能达到97.3%。为提高半导体的光催化活性提供了一条可行的路径。     

活性炭负载纳米TiO_2光催化降解甲醛废水研究

甲醛对人和温血动物的毒性很强,如果人类长期饮用被甲醛污染的水源,会引发头昏、贫血以及各种神经系统疾病.为此,研究学者对甲醛废水的处理进行了很多的试验研究.目前处理甲醛废水的主要方法有:芬顿法、光催化氧化法、湿式氧化处理等高级氧化技术,二氧化氯法,蒸汽吹脱法,氧化吸附法,SBR工艺等.     

Photocatalytic decomposition of oil films floating on water using TiO_2 supported on hollow glass microbeads by sunlight

The feasibility of photocatalytic decomposition of oil films floating on water using TiO2 supported on hollow glass microbeads was studied.The results showed that 100% of ethylbenzene and 78% of dodecane can be photocatalytically removed after 8 h illumination with sunlight.The TiO2 supported on the hollow glass microbeads was not easily detached from the beads.After 150 h illumination there was no significant loss of the photocatalytic activity of TiO2 Some intermediate products of photocatalytic decomposition of dodecane were detected.     

Photocatalytic degradation of 2,4,6-trinitrotoluene

A Pt/TiO2 photocatalyst was used in the photocatalytic degradation of 2,4,6-trinitrotoluene (TNT) under the irradiation of the simulated sunlight. The results show that the destruction of TNT is faster and more complete with the photocatalyst. The photocatalytic degradation of TNT follows first order kinet-ics. The transformation of nitryl groups of TNT molecules into nitrite and nitrate ions may be acceler-ated in the presence of the Pt/TiO2 photocatalyst. Compared with that without the catalyst, the concentration of nitrate ions was improved 32.3 times within 2.5 h.     

Gas-phase photocatalytic oxidation of benzene over titanium dioxide loaded on Bi_(12)TiO_(20)

TiO2 was prepared by sol-gel method using tetrabutyl titanate as precursor. TiO2 was loaded on Bi12TiO20. The photocatalyst with different TiO2 loading was calcined at 723 K. The photocatalytic activity of decomposition gaseous benzene was investigated in a batch reactor. The prepared photocatalyst was characterized by UV-vis diffuse reflectance. The result showed that TiO2/Bi12TiO20 absorbed much more ultraviolet light than Ti02 in the ultraviolet light region and showed red shift. The results indicated that the prepared photocatalyst can greatly promote the photocatalytic activity. The 2.0% TiO2/Bi12TiO20 system exhibited the highest photocatalytic activity.