双元素掺杂对纳米二氧化钛光催化降解甲基橙的影响

应用冷冻干燥技术，采用溶胶——凝胶法制备了同时掺铁镧、铁锡的双元素掺杂纳米Tiq粉体材料，通过XRD、激光粒度分析仪、扫描电镜分析仪的检测，粒径为60～70nm，比表面积约为36～45m^2／g，粒度均匀，全为锐钛矿型。通过甲基橙溶液光催化降解实验，比较了不同掺杂纳米TiO2粉体的催化性能，实验发现在这些改性的TiO2粉体材料中，以同时掺0.05％铁和掺0.02％镧的效果最好。在光催化降解实验中，掺0．05％铁的基础上掺0．02％镧的粉体光催化效率约为在掺0.05％铁基础上掺0.02％锡的粉体的光催化效率的1．5倍。     

纳米TiO2的复合改性及其光催化性能

采用甲基丙烯酸甲酯、硝酸镧对纳米TiO2进行复合改性,以亚甲基蓝作为光催化降解对象,讨论改性条件对纳米TiO2光催化性能的影响.结果表明,纳米TiO2经过改性后,其光催化性能均有所提高,尤其是经过硝酸镧复合改性后,其光催化性能明显好于未改性纳米TiO2和单一改性纳米TiO2.甲基丙烯酸甲酯用量、硝酸镧用量、热处理温度、热处理时间对纳米TiO2光催化性能均有影响.复合改性纳米TiO2的较佳工艺条件为:甲基丙烯酸甲酯用量为44.09%,硝酸镧用量为2.31%,热处理温度为500℃,热处理时间为5 h.     

掺镧纳米TiO2的光催化性能研究

研究了掺镧纳米TiO₂的物理特性及光催化活性，探讨了它们之间的关系，通过对甲基橙和罗丹明两种不同结构物质的降解实验，发现掺镧纳米TiO₂光催化性能具有广泛性。用于实际印染废水处理，再次验证掺镧能提高TiO₂的光催化效能，掺镧摩尔分数为0.02%时光催化效果最好。     

不同碳黑种类掺杂对TiO2纳米粉光催化性能的影响

本文采用溶胶-凝胶法制备了具有光催化性能的TiO2纳米粉体,研究了3种碳黑（普通炭黑,接枝碳黑,普通炭黑加双氧水）对其光催化性能的影响。结果表明,3种炭黑的加入都有利于提高TiO2纳米粉体的光催化性能,掺杂浓度在0.75%最合适。掺0.75%普通炭黑加双氧水的TiO2纳米粉体具有最大的比表面积,光催化活性最高,掺接枝碳黑TiO2纳米粉末次之,掺普通炭黑TiO2纳米粉末最差。     

江西理工大学研制出自洁净抗菌陶瓷

日前,江西理工大学材料与化学工程学院研制成功具有光催化自洁净和抗菌性能的新型镧掺杂纳米TiO2膜陶瓷。该校的科研人员采用溶胶—凝胶法和浸渍提拉法在釉面陶瓷表面覆盖了掺独立镧TiO2薄膜,经焙烧后制备了表面光滑平整、无“彩虹效应”,具有自洁净抗菌功能的陶瓷。有关部门专     

铁和镧共掺杂二氧化钛的光催化活性

采用溶胶-凝胶法制备了纯的和铁镧共掺杂的TiO2纳米粒子,对样品进行了X射线和紫外-可见吸收光谱分析。结果表明,500℃煅烧的未掺杂和共掺杂TiO2均呈锐钛矿结构,铁镧共掺杂抑制了TiO2粒径的长大,使TiO2的吸收带边红移且在可见光区的光吸收增强;光催化降解甲基橙表明,未掺杂的TiO2光催化活性高于P25,而适量铁镧共掺杂TiO2光催化活性进一步得到提高,最佳掺杂比是0.05%的Fe和0.5%的La。     

纳米TiO_2光催化降解溴虫腈

用溶胶-凝胶法制备了纳米级TiO2和不同掺铁量的TiO2纳米粒子,用XRD、TEM、FTIR等手段对其进行了表征。将制备的TiO2和掺铁TiO2纳米粒与溴虫腈农药配制成悬浮液,分别作光降解实验。结果表明,掺铁TiO2对溴虫腈的光催化降解速率较TiO2高,随着铁离子浓度的增大,溴虫腈的降解率先上升后下降,最大催化活性的掺铁量为n(Fe3+)/n(TiO2)=0.08,TiO2在酸性或碱性条件下对溴虫腈的光催化活性较中性高,而掺铁TiO2随着溴虫腈悬浮液pH升高催化活性下降。该研究为农药纳米功能化制剂的制备,及利用光催化降解农药减少环境污染提供了实验依据。     

钛/铟复合材料的光催化性能研究

采用溶胶-凝胶法,应用冷冻干燥技术,制备了掺铟纳米TiO2,采用X射线衍射、激光粒度分析仪、扫描电镜、紫外可见光谱等测试手段,分析In2O3,与TiO2复合后,不同含铟量的复合半导体的比表面积、晶型、颗粒大小等特性及其对罗丹明与甲基橙光催化脱色降解的影响,将半导体的物理性能与光催化性能结合起来,探讨了它们之间的关系。通过实验,发现掺铟的纳米TiO2复合材料,并不是只对特定结构的物质才有降解作用,处理实际的印染废水再次验证掺铟TiO2能提高TiO2的光催化效能,其中铟与TiO2的物质的量比为0．1％的复合材料光催化效果最好。     

预涂镧盐的二氧化钛薄膜制备和性能

在玻璃表面预涂一层硝酸镧掺杂的TiO2薄膜.研究了镧盐掺杂对样品相结构、晶粒尺寸和光催化降解亚甲基蓝活性的影响.利用相结构与TiO2薄膜光催化活性关系,探讨了镧盐掺杂对TiO2薄膜的光催化活性的影响.结果表明,与纯TiO2薄膜相比,适量掺杂镧盐可以显著提高其光催化活性.当预涂w(硝酸镧)为0.3%溶液时,TiO2薄膜的光催化活性最佳,降解率为94.56%,镧盐强烈地抑制TiO2由锐钛矿相向金红石相的转变,减小晶粒尺寸,这两方面均有利于提高光催化活性.     

Ag掺杂TiO2纳米薄膜光催化活性研究进展

TiO2在光催化和光电转化领域拥有十分广阔的应用前景,近几年来备受研究人员广泛关注.本文综述了TiO2光催化反应机理以及掺银TiO2纳米薄膜的制备方法,其中包括溶胶凝胶法、微乳液法、电弧溅射法、阳极氧化法以及表面化学反应等.主要讨论了Ag单掺杂和Ag与其他元素共掺杂的TiO2纳米薄膜光催化活性的研究进展,并对二者进行比较,展望了其发展方向.共掺杂TiO2纳米薄膜因比单掺杂薄膜具有更优异的光催化性能,是未来的主要研究方向之一.     

搪瓷表面TiO2薄膜的制备和光催化性能表征

以搪瓷表面为载体,在常温下采用溶胶-凝胶法制备二氧化钛(TiO2)薄膜,研究使用未添加聚乙二醇(PEG)的溶胶和添加少量PEG的溶胶制备出的薄膜在催化性能上的区别.结果表明,薄膜在450℃热处理1h后,具有完整的锐钛矿相和良好的光催化性能;使用添加少量PEG的溶胶制备的薄膜,其光催化能力更好.     

Fe3+掺杂TiO2光催化自洁玻璃的研制

采用溶胶—凝胶法和浸渍提拉法在普通钠钙玻璃表面负载了一层纯TiO2。膜或掺杂不同量的Fe3 件的TiO2膜，经灼烧后制备了具有自洁功能的新型玻璃。通过以邻苯二酚紫作为有机污染模拟物的光催化对比实验发现，掺杂适量的Fe3^ 件可以有效的提高光催化效率，过量掺杂则反而降低光催化活性，最佳掺杂量约为1．5%。掺杂1．5％的Fe3^ 件后，紫外一可见吸收光谱的吸收峰增强了大约1倍，而且吸收范围红移了大约30nm。同时对灼烧温度和灼烧时间进行了研究，确定了较优化的制备条件。     

Preparation, characterization and photocatalytic behavior of WO3-fullerene/TiO2 catalysts under visible light

WO3-treated fullerene/TiO2 composites (WO3-fullerene/TiO2) were prepared using a sol-gel method. The composite obtained was characterized by BET surface area measurements, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, and UV-vis analysis. A methyl orange (MO) solution under visible light irradiation was used to determine the photocatalytic activity. Excellent photocatalytic degradation of a MO solution was observed using the WO3-fullerene, fullerene-TiO2, and WO3-fullerene/TiO2 composites under visible light. An increase in photocatalytic activity was observed, and WO3-fullerene/TiO2 has the best photocatalytic activity; it may attribute to the increase of the photo-absorption effect by the fullerene and the cooperative effect of the WO3.     

纳米红磷的制备及其光降解性能的研究

采用水热-研磨的方法处理商业红磷(C-RP)获得纳米级RP光催化剂。选择罗丹明B(RhB)考察该催化剂的光催化活性。研究结果表明C-RP经水热后选择研磨处理,其光催化活性显著提高。当研磨2h时,光催化剂体现出最高的光催化活性,其光降解速率常数是3.16×10^-2 min^-1,是C-RP的8.25倍。系列表征结果表明C-RP水热-研磨处理后提高其光催化活性的主要原因是:粒径变小,具有更多的活性位点,提高光生电子和空穴的迁移和分离。另外,通过捕获剂实验,最终确定在光降解反应过程中起主要作用的是光生空穴(h^+)和超氧基自由基(O2^·-)。     

掺杂铁TiO_2纳米微粒的制备及光催化性能

以钛酸四丁酯为前驱体,采用溶胶-凝胶法制备了Fe3+掺杂改性纳米TiO2光催化剂,通过纯TiO2和掺铁TiO2分别做光催化剂时甲基橙溶液在紫外光下的光催化降解试验发现,掺杂铁离子可以有效提高TiO2的光催化活性,结果表明:选用Fe3+掺杂量为0.05%,煅烧温度在500℃下得到的Fe3+-TiO2催化剂,在甲基橙溶液pH值为3,催化剂投加量为1 g/L时,其光催化活性达到最佳效果。     

掺杂铁TiO2纳米微粒的制备及光催化性能

以钛酸四丁酯为前驱体,采用溶胶-凝胶法制备了Fe^3＋掺杂改性纳米TiO2光催化剂,通过纯TiO2和掺铁TiO2分别做光催化剂时甲基橙溶液在紫外光下的光催化降解试验发现,掺杂铁离子可以有效提高TiO2的光催化活性．结果表明：选用Fe^3＋掺杂量为0．05％,煅烧温度在500℃下得到的Fe^3＋-TiO2催化剂,在甲基橙溶液pH值为3,催化剂投加量为1g／L时,其光催化活性达到最佳效果。     

水热法制备Eu复合BiVO4纳米片及其光催化降解性能

水热法制备了以聚乙二醇(PEG-200)为模板剂的稀土元素Eu复合BiVO₄光催化剂,并对材料进行XRD、SEM、UV-vis DRS、BET的表征和分析.以光催化降解甲基蓝(MB)效率作为光催化活性的指标,考察Eu复合对BiVO₄光催化活性的影响.结果表明:Eu复合可使BiVO₄的晶型发生转变,同时又抑制四方相晶体生长,使晶粒尺寸变小,比表面积增大.复合样品中,部分Eu³⁺进入BiVO₄晶格内取代Bi³⁺,使晶形发生畸变,有利于光催化活性的提高.当Eu的复合量为50%时,光催化降解甲基蓝的效率最高,可见光照射120min降解效率可达到90%,较纯BiVO₄的光降解效率明显提高.     

Fabrication of bifunctional nanocomposite for dye degradation

An effective photocatalytic system is designed to treat with methylene blue. Graphene oxide matrix was decorated with cobalt ferrite and zinc oxide nanoparticles, providing it with dual functionality. The nanocomposite was prepared via sonochemistry. Structural characterization was done by X-ray diffraction. Morphology was observed by scanning electron microscopy while elemental analysis confirmed the purity of the synthesized nanocomposite. The photocatalytic activity of nanocomposite was tested for denaturing methylene blue under solar conditions. Enhanced photocatalytic activity was observed due to trapped electron-hole pairs at graphene oxide surface and other interfaces of the nanocomposite. The efficiency of photocatalyst was calculated as 98% within 15 min which was further examined till 5 more repeated cycles.     

Study on the photocatalytic property of La-doped CoO/SrTiO3 for water decomposition to hydrogen

The purpose of this study is to investigate the effect of La doping on the photocatalytic property of CoO/SrTiO₃. The experimental results show that a suitable concentration of La doping greatly improved the photocatalytic activity of CoO/SrTiO₃. The activity first increased, reached a maximum, and then decreased drastically with increasing doping concentration. The physical properties of the catalyst were characterized using XRD, SEM and UV-visible diffuse reflectance spectra. The influence of loading amount of co-catalyst CoO on the photocatalytic activity of La-doped SrTiO₃ was also studied and it was found that the optimum loading amount increased with increasing doping concentration.     

Hydrothermal Synthesis and Photocatalytic Activity of Whisker-Like Rutile-Type Titanium Dioxide

Nanowhiskers of rutile-type titanium dioxide (TiO₂) were synthesized by a simple hydrothermal treatment of a water-soluble titanium–glycolate complex at 473 K. The aspect ratio of the obtained rutile particles could be controlled by changing the concentration of the glycolic acid additive in the starting aqueous solution of the titanium complex. According to high-resolution transmission electron microscopy, whisker-like nanoparticles grow along the c -axis of rutile, the side facets of which are (110), (−110), (1–10), and (−1–10). Glycolic acid controls promotion of the rutile particles in the specified direction due to its preferred adsorption on the titanium-rich facets. Evaluation of the photocatalytic activity of the synthesized TiO₂ was performed in terms of decomposition of oxalic acid in an aqueous system under ultraviolet irradiation. It turned out that this particular whisker-like shape is responsible for the tremendous enhancement of rutile photocatalytic activity, and even rutile samples with low surface area demonstrated photocatalytic performance comparable with one of the best nanosized anatase photocatalytic materials. Therefore, it can be concluded that the (110) rutile facet plays an important role in the photocatalytic oxidation reaction, and that it exhibits higher photocatalytic activity than the (001) facet in the decomposition of oxalic acid.