Co2+离子掺杂对TiO2结构与光催化活性的影响

论文采用溶胶-凝胶法制备Co2+掺杂的TiO2纳米粉末,以苯酚为目标污染物研究了Co-TiO2在不同的光源（紫外、可见）下的光催化活性,并利用XRD、EFSEM、UV-DRS和XPS等手段分析Co-TiO2结构与光催化活性的关系。结果表明,一部分Co2+离子成功进入TiO2晶格,有助于金红石相向锐钛矿相转变;另一部分Co2+离子在催化剂表面生成Co3O4,可与TiO2形成p-n异质结,两种结构变化均增强了光催化活性,且催化剂光谱吸收范围拓展至可见光区域。当Co2+掺杂量为1.0%,焙烧温度为773K时,Co-TiO2比表面积约为28.4m2/g,锐钛矿含量达到70.6%,光催化活性最好。2小时内,在紫外和可见光下,Co-TiO2对苯酚的降解率分别为97.7%和52.3%,均优于纯TiO2。     

稀土离子(Sm~(3+),La~(3+))掺杂纳米TiO_2光催化性能研究

以钛酸四丁酯和稀土氧化物Sm2O3、La2O3为原料,分别制备了掺杂稀土离子Sm3+和La3+的纳米TiO2光催化剂,分别进行了两种离子掺杂纳米材料在甲基橙溶液中的光催化降解实验。通过对制备条件优化,研究了光降解条件对降解效果的影响。结果表明:La3+掺杂纳米TiO2材料的光催化活性要优于Sm3+掺杂纳米TiO2材料.     

Mn~(2+)掺杂对纳米TiO_2薄膜光催化活性的影响

采用溶胶-凝胶法制备Mn2+掺杂的TiO2薄膜光催化剂,进行甲醛的光催化实验,考察Mn2+掺杂量、薄膜焙烧温度、溶胶体系pH值及薄膜厚度对光催化性能的影响.结果表明,Mn2+掺杂量为1.0%,焙烧温度500℃1 h,加硝酸溶胶体系pH=4,镀膜5层时,Mn2+掺杂TiO2薄膜光催化活性最高.150 min后甲醛降解率达79%,是单纯TiO2薄膜的1.4倍.     

S掺杂TiO2光催化剂的可见光催化降解甲基橙研究

采用溶胶-凝胶法合成了S掺杂TiO2光催化剂.XPS测试结果表明钛离子主要是以+4价形式进入到了TiO2的晶格中,导致TiO2的禁带宽度变窄,将TiO2的吸收光谱拓展至可见光区,故可在可见光下对甲基橙进行光催化降解;在降解过程中,甲基橙首先形成芳香环类中间产物,然后继续开环降解和矿化;稳定性实验表明样品具有良好的稳定性.     

超声条件下制备氮掺杂TiO2及其光催化活性研究

为拓展二氧化钛对可见光的响应,超声条件下采用溶胶凝胶法以三乙胺为氮源制备出N掺杂的纳米TiO2光催化剂;以甲基橙的光催化降解为探针反应,评价其光催化活性;运用XRD、TEM、XPS和UV-Vis DRS等技术考察了超声及N掺杂对TiO2微晶尺寸、晶体结构、表面组成与光学性能的影响.结果表明,所制备N掺杂TiO2为纯锐钛矿型,超声抑制了光催化剂粒晶的增大,减弱了颗粒间的硬团聚;N掺杂使TiO2光谱响应波长拓宽至可见光区,有效改善了TiO2的可见光活性,对甲基橙溶液的降解速率比纯TiO2提高了69.9%.     

Ag+/Fe3+共掺杂纳米TiO2薄膜光催化性研究

用溶胶-凝胶法制备了Ag+/Fe3+复合掺杂的纳米TiO2薄膜,以甲基橙为光催化反应模型化合物,考察了复合掺杂光催化剂的活性.Ag+、Fe3+的掺入量分别为wAg+=0.043%、wFe3+=0.1%,且同时掺入TiO2光催化时具有最佳的光催化效率.并通过XRD、AFM、UV-Vis对复合掺杂薄膜进行了表征.结果表明,金属共掺杂可以促进纳米TiO2由锐钛矿向金红石相转化,平均晶径约为30 mm左右;Fe3+掺入可能以替代的方式占据TiO2晶格中Ti4+的位置,并在TiO2禁带中产生掺杂能级,使吸收边红移,并在可见光区有极低的透过率.Ag+的掺入在光催化过程中有效地抑制光生电子与空穴的复合,提高掺杂TiO2的光催化效率.     

TiO2光催化剂的改性研究进展

TiO2作为一种光催化剂在用于环境污染的治理方面得到了非常广泛的研究,但是由于其自身存在不能响应可见光和量子效率低的缺陷而限制了它的应用.因此实现TiO2的可见光催化一直是研究的热点.本文综述了掺杂各种金属离子、非金属离子对TiO2的光催化活性的影响以及利用贵金属沉积、染料光敏化等方法来改善TiO2光催化性能的研究.     

Bi_9V_2ClO_(18)新型光催化剂的制备与光催化活性评价

以BiOCl、Bi_2O_3、NH_4VO_3为原材料,采用固相合成法制备了Bi_9V_2ClO_(18)新型光催化剂,通过XRD、SEM和HRTEM对样品的物相、形貌和结晶质量进行了表征,测试了样品的紫外-可见漫反射吸收光谱。结果表明:其吸收边为465nm,禁带宽度为2.67eV。采用罗丹明B(RhB)、亚甲基蓝(MB)为目标污染物,测试了Bi_9V_2ClO_(18)光催化剂的可见光光催化活性。在可见光下辐射9h,RhB降解率达82%;可见光下辐射5h,MB降解率达83%。测试结果表明:所制备Bi_9V_2ClO_(18)材料是可见光响应型光催化剂,在可见光辐照下对罗丹明B和亚甲基蓝的光降解主要依赖于光催化剂的直接光降解机制。     

氧化沉淀法制备掺杂纳米TiO2

实验以偏钛酸为原料,以硝酸锶和硫脲为掺杂源,在冰水浴条件下,用氧化沉淀法在室温条件下制备了锐钛矿型的掺杂纳米TiO2,借助于扫描电子显微镜等方法研究探索此掺杂纳米TiO2的光催化活性。结果表明:在以硝酸锶离子和氮元素混掺下纳米TiO2具有好的光催化活性,以MB溶液的光催化降解为参照,在紫外光下光降解率达到55.99%,同时可见光下的光降解率达到48.48%。     

Fe~(3+)掺杂TiO_2玻璃薄膜太阳光催化降解H酸的研究

采用溶胶-凝胶法在玻璃表面上制备了掺杂Fe3+的TiO2薄膜,用XRD、IR对其进行表征.在太阳光的照射下,以H酸为目标物,用自制敞开连续流平板式光催化反应器,进行了光催化法降解试验.结果表明:适量Fe3+的掺杂可明显提高TiO2玻璃薄膜在太阳光下的催化性能,掺Fe3+的摩尔质量百分数为(Fe3+/TiO2)0.06%时的光催化活性最高.太阳光照射3 h,H酸脱色率达到72.5%,反应速率遵从Langmuir-Hinshelwood方程,表观速率常数K′=0.007 4 min-1.     

Highly Efficient Synthesis of Environmentally Friendly Ag-modified TiO_2 Nanoflowers to Enhance Photocatalytic Performance

Ag-modified TiO_2 nanoflowers were prepared using a two-step process. The experimental process is green and free from contamination and can be synthesized directly at room temperature. Compared with pure TiO_2, Ag-modified TiO_2 enhances the absorption of visible light and effectively promotes the detachment of photoelectron pairs, Ag-TiO_2 has a significantly enhanced visible light response activity to photodecomposition of methyl orange(MO). It is shown that the strong interaction between Ag nanoparticles and TiO_2 enhances the photocatalytic activity of TiO_2 nanoflowers. The self-made open-air reactor was used to test the photocatalytic performance of different samples. The results showed that Ag-modified TiO_2 nanoflowers had excellent photodegradation ability. After repeated photodegradation of MO, Ag-modified TiO_2 nanoflowers showed good stability.     

掺杂金属卟啉的TiO_2薄膜对活性艳红X-3B染料的光催化降解性能

采用溶胶凝胶的方法,将具有高光敏性的四(对羟基)苯基锌卟啉(ZnTHPP,下简称锌卟啉)在钛酸丁酯[Ti(OBu)4]水解的条件下均匀嵌入到了TiO2无机网络中,又采用旋涂法制备了ZnTHPP/TiO2复合薄膜。利用UV Vis吸收光谱对薄膜的紫外可见光吸收性质进行了研究,结果表明锌卟啉的加入能有效的拓宽TiO2的可见光吸收范围。通过光催化降解活性艳红X 3B染料实验,对所制备的ZnTHPP/TiO2复合薄膜的光催化活性进行了考察,研究发现以ZnTHPP/TiO2作为光催化剂对活性艳红X 3B染料能有效的降解,表现出了较好的可见光催化活性。     

Fe3+-TiO2/SiO2气相光催化降解乙醛反应动力学研究

用浸渍法制备了Fe^3 -TiO2／SiO2负载型光催化剂,并进行了光催化降解气相中乙醛的实验和动力学研究．结果表明,Fe^3 掺杂量(nFe3 ／nTi4)为0．5％时光催化降解乙醛的效率最高;水气的存在提高了Fe^3 -TiO2／SiO2负载型催化剂的光催化活性,但使Fe^3 -TiO2纳米粉的光催化活性降低;O2的存在使Fe^3 -TiO2纳米粉和Fe^3 -TiO2／SiO2负载型催化剂的催化活性均有所降低;光强减弱使乙醛降解率下降,反应速率与光强之间呈近似线性关系;光催化降解气相中乙醛的动力学可以用Langrauir-Hinshelwood动力学方程描述．     

Photogenerated carrier transfer mechanism and photocatalysis properties of TiO2 sensitized by Zn（ Ⅱ ） phthalocyanine

The Zn(Ⅱ) phthalocyanine sensitized TiO2(ZnPc-TiO2) nanoparticles were prepared by hydrothermal method via impregnation with ZnPc.The as-prepared photocatalysts were characterized by X-ray diffractometry(XRD) and diffuse reflectance spectroscopy(DRS),and the surface photovoltage spectroscopy(SPS) and photocatalytic degradation of rhodamine B(RhB) were studied under illuminating.The experimental results indicate that TiO2 sensitized by ZnPc extends its absorption band into the visible region effectively,and ...     

Synthesis of M(M=Co~(2+),Co~(2+)/Ni~(2+))-doped FeS_2 Nanospheres with Enhanced Visible-light-induced Photocatalytic Activity

Nano-spherical Co~(2+)-doped FeS_2 was synthesized through a simple solvothermal method. The products were investigated using XRD, FE-SEM, BET, ICP, EDS, TEM, HRTEM, XPS, and UV-vis spectroscopy. The results indicated that Co~(2+) ion could change the particle nucleation process and inhibited the particle growth of FeS_2. In addition, when the content of doped Co~(2+) was 15%, the degradation efficiency of methylene blue(MB) achieved 60.72% after 210 min irradiation, which increased by 52.01% than that of the undoped FeS_2. Moreover, comparison experiments also demonstrated that the M(M=Co~(2+), Co~(2+)/Ni~(2+))-doped FeS_2 photocatalytic activity efficiency sequence was Co~(2+) Ni~(2+)Co~(2+)/Ni~(2+). This is ascribed to the fact that the Co~(2+) doping could induce the absorption edge shifting into the visible-light region and increased the surface area of the samples. The effect mechanisms of M-doping on the band gap and the photocatalytic activity of FeS_2 were also discussed.     

微波辐射制备TiO_2薄膜光催化性能研究

采用微波辐射法由溶胶制备出TiO2薄膜,用XRD和TEM对催化剂进行了表征。以甲基橙为模拟污染物,考察了微波功率和膜层厚度对TiO2光催化活性的影响,并实际考察了TiO2薄膜对啤酒废水的降解效果。结果表明:制备的TiO2薄膜具有较高光催化活性,微波功率300 W时光催化活性最大,对啤酒废水具有良好的处理效果。     

掺铁TiO2纳米微粒的制备及光催化活性

采用溶胶-凝胶法制备了不同掺铁量及不同pH值下的一系列TiO2光催化剂，并以高压汞灯为光源，罗丹明B为目标降解物，对其光催化活性进行了研究．实验表明，Fe^3 ．TiO2比纯TiO2具有更好的催化活性，且Fe^3 的最佳掺入量为0．05％，最佳制备的pH值为5。     

金属酞菁敏化二氧化钛可见光催化降解染料废水的研究

研究了染料敏化半导体光催化剂-酞菁镁/TiO_2复合粒子在可见光波段的光催化性能.通过溶胶-凝胶的方法制得TiO_2胶体再进行焙烧,得到二氧化钛粉末和薄膜,再用酞菁镁敏化,制得酞菁镁/TiO_2复合粒子.利用X射线衍射、扫描电子显微镜、红外光谱和X光电子能谱分析等方法对TiO_2和酞菁镁/TiO_2复合粒子的物理性质进行了表征;并以亚甲基蓝作为目标物研究其光催化性能.结果表明,酞菁镁可以敏化二氧化钛,使其吸收波长红移,并具有较好的光催化性能.     

Enhanced Photoelectric Property of Mo-C Codoped TiO_2 Films Deposited by RF Magnetron Cosputtering

Mo-C codoped TiO_2 films were prepared by RF magnetron cosputtering. Ultraviolet-visible spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray Analysis and X-Ray Diffraction were used to study the influences of codoping on energy gap, surface morphology, valence states of elements, ions content and crystal structure, respectively. The concentration of photogenerated carriers was measured by studying photocurrent density, while catalytic property was evaluated by observing degradation rate of methylene blue under visible light. A Mo-doped TiO_2 film, whose content of Mo had been optimized in advance, was prepared and later used for subsequent comparisons with codoped samples. The result indicates that Mo-C codoping could curtail the energy gap and shift the absorption edge toward visible range. Under the illumination of visible light, codoped TiO_2 films give rise to stronger photocurrent due to smaller band gaps. It is also found that Mo, C codoping results in a porous surface, whose area declines gradually with increasing carbon content. Carbon and Molybdenum doses were delicately optimized. Under the illumination of visible light, sample doped with 9.78at% carbon and 0.36at% Mo presents the strongest photocurrent which is about 8 times larger than undoped TiO_2 films, and about 6 times larger than samples doped with Mo only.