首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
掺铁TiO2-活性炭复合材料的制备及其光催化活性   总被引:9,自引:0,他引:9  
通过浸渍法将掺铁TiO2溶胶负载到活性炭上制备掺铁TiO2-活性炭复合光催化剂材料,并对其结构特征、吸附特性、可见光光催化活性和再生性能进行研究.结果表明,掺铁TiO2-活性炭复合材料具有很大的比表面积,对有机污染物具有优越的吸附性能,而其比表面积则随着掺铁TiO2-活性炭的质量比的增大而逐渐减小.在可见光下,复合光催化剂材料由于Fe3 的引入TiO2中,对亚甲基蓝溶液具有高的光催化活性,其中经过500℃热处理的载钛量为5%(质量分数)的复合光催化剂材料的光催化活性最佳.复合光催化剂具有优越的再生性能,经再生处理可多次重复使用.  相似文献   

2.
以钛酸丁酯为前驱体,采用溶胶-凝胶法制备了Fe、N离子共掺杂的、以活性炭(AC)和活性炭纤维(ACF)为载体的TiO2/AC和TiO2/ACF光催化剂.采用扫描电镜、X射线衍射仪、紫外-可见光分光光度计等对催化剂样品进行了表征.选取甲苯为模型化合物进行光催化降解实验,研究了催化剂制备过程中离子掺杂量、抑制剂种类、焙烧温度、载体种类以及循环使用次数对催化剂活性的影响.结果表明:TiO2在ACF上的分散效果好于在AC上;TiO2以颗粒状镶嵌在AC孔隙内、以膜状包覆在ACF表面,所制备的光催化剂均以锐钛矿相存在;Fe、N离子共掺杂实现了催化剂的可见光响应;以冰醋酸为抑制剂、N和Fe离子掺杂量均为8%(摩尔分数)、500℃下焙烧2 h时,所得的TiO2/ACF光催化剂对气相甲苯的降解活性最高,循环使用效果最好.  相似文献   

3.
以饱和尿素溶液水解沉淀工艺制备水合TiO2,再于温度600℃的空气气氛下煅烧2h,制得淡黄色的N/TiO2光催化剂,并以活性艳红X-3B、2,4-二氯苯酚及CH3COO-作模型污染物,着重研究了N/TiO2的可见光催化反应特性. XPS结果表明,掺杂N是以形成Ti-N化学键的形式进入了TiO2的晶格. UV-Vis结果表明,N/TiO2光催化剂对波长不低于400nm的可见光有明显的吸收效应. 光催化结果表明:N/TiO2在主峰420nm的荧光灯作用下,对活性艳红X-3B及2,4-二氯苯酚有明显的降解作用,但对CH3COO-无降解作用,然而当在主峰254nm或365nm的紫外灯作用下时能降解CH3COO-;激发光源波长在紫外区还是可见光区与光催化的氧化能力是密切相关的.  相似文献   

4.
以钛酸四丁酯和Fe(NO3)3.9H2O为原料,在室温下制备得到TiO2和掺铁TiO2光催化剂粉体;以紫外灯为光源,甲基橙溶液为目标降解物,在紫外-可见分光光度计上对其光催化活性进行了研究。实验结果表明:掺杂Fe3+的TiO2光催化剂比纯TiO2具有更好的催化活性,在Fe3+掺入量为0.05%,催化剂加入量为2g,紫外光照时间为3h时,掺铁TiO2光催化剂可达到83%的光催化降解效率。  相似文献   

5.
为了提高纳米TiO2催化剂的光催化氧化性能,采用溶胶-凝胶法,以酞酸丁酯为原料制备铁掺杂纳米TiO2光催化剂(Fe-TiO2).分别采用X射线衍射和紫外-可见光漫反射对其晶相和光催化活性进行表征.以偶氮结构的弱酸性染料溶液为目标降解物,研究在可见光照射下Fe-TiO2的光催化性能.结果表明,Fe-TiO2光催化剂的晶相为单一锐钛矿相,粒径为17.7nm;吸收边带红移至500nm,禁带宽度减小到2.48eV.在可见光下光催化反应180min,Fe-TiO2光催化剂对弱酸性染料的降解率达99.86%.  相似文献   

6.
以钛酸丁酯为前驱体,采用溶胶-凝胶法制备了Fe、N离子共掺杂的TiO2/AC和TiO2/ACF负载型光催化剂,采用SEM、XRD、UV-Vis分光光度计等分析方法对催化剂样品进行了表征。选取甲苯为室内气相空气污染物的模型化合物进行光催化降解实验,探讨了催化剂制备过程中离子掺杂量、抑制剂种类、焙烧温度以及载体等对光催化剂活性的影响。结果表明, 催化剂在ACF上的分散效果优于AC上,制备的光催化剂均以锐钛矿相存在,Fe、N离子共掺杂实现了光催化剂在可见光区和紫外光区的双增强;以冰醋酸为抑制剂、离子掺杂量分别为N 8%和Fe 8%,ACF为载体,500 ℃下焙烧2 h所得TiO2/ACF光催化剂对气相甲苯的降解活性最高。  相似文献   

7.
通过溶胶凝胶法,以硝酸铁为铁源、尿素为氮源,分别制备了铁掺杂、氮掺杂、铁氮共掺杂二氧化钛粉末。采用X射线衍射仪,紫外-可见光谱仪等对样品进行表征和分析。并以亚甲基蓝作为目标降解物,来评价样品的光催化性能。结果表明,500℃下制备的催化剂均为锐钛矿相,结晶性较好,掺杂使材料的吸收光谱发生红移,掺铁5%,掺氮12%时对可见光的吸收效果最好。光催化6h对亚甲基蓝的降解效果效果Fe-N-TiO2>Fe-TiO2>N-TiO2>纯TiO2。Fe、N共掺杂产生协同作用,使TiO2的光催化性能明显优于单掺杂样品和纯TiO2。  相似文献   

8.
采用溶胶-凝胶法制备TiO2溶胶,负载于玻璃微珠表面,并采用NH3气氛焙烧法制得掺氮纳米TiO2薄膜.运用X射线粉末衍射仪、扫描电镜和紫外-可见漫反射吸收光谱等技术,考察不同焙烧温度和负载次数对掺氮的TiO2样品性能的影响.研究结果表明,350,400,450℃热处理的样品的晶相为锐钛矿相,而在500℃时开始出现金红石相,且随温度的进一步升高,金红石相的含量逐渐增多;掺氮的TiO2样品具有可见光吸收性能,450℃热处理的样品达到最佳,其吸收边红移至约720 nm.另外,薄膜的厚度对样品的光催化性能影响显著,负载3次后,样品对罗丹明B的光催化活性最高.  相似文献   

9.
掺氮可见光响应TiO2-xNx光催化薄膜的制备及性能初探   总被引:1,自引:0,他引:1  
采用反应磁控溅射法在玻璃基片上制备N掺杂TiO2-xNx薄膜和纯TiO2薄膜,并且对两种薄膜样品分别进行了300、400和500℃的退火处理.采用X射线光电子能谱仪(XPS)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)和紫外-可见光光度计(UV-Vis)对经过退火处理的样品进行了表征.结果表明:成功制备了N掺杂TiO2-xNx薄膜,部分N进入了TiO2薄膜晶格,并且以N-O键形式存在;N掺杂TiO2-xNx薄膜和纯TiO2薄膜相对比,晶型和表面形貌没有什么太大的区别,但通过紫外-可见光吸收谱图可以发现经过400℃退火处理的N掺杂TiO2-xNx薄膜吸收带边从纯TiO2薄膜的400 nm红移到455 nm.  相似文献   

10.
采用溶剂热法合成了可见光响应的TiO2/g-C3N4复合光催化剂,并对TiO2/g-C3N4进行质子化处理。通过X射线衍射、氮气吸附-脱附BET法、扫描电子显微镜、透射电子显微镜、傅里叶红外光谱、紫外-可见漫反射和荧光光谱等方法对样品进行了表征,并以甲基橙(MO)光催化降解为模型反应,考察了可见光下制备的样品的光催化性能。结果表明,多孔TiO2纳米晶与g-C3N4形成具有"芝麻饼"形貌的复合结构;TiO2/g-C3N4复合光催化剂的吸收带边扩展到465nm,较TiO2出现明显红移;TiO2与g-C3N4能带匹配耦合,有效地抑制了电子与空穴的复合;质子化处理过程能够提高可见光区吸收强度和电子的传导能力,增强了TiO2的光催化活性。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号