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1.
对P-25 TiO2光催化剂在空气气氛中进行程序升温热处理,用于对高浓度苯酚废水的光催化降解.考察了焙烧温度、催化剂用量、溶液pH和H2O2对光催化降解苯酚的影响,并采用XRD和BET方法对各种温度焙烧的P-25 TiO2进行了表征.结果表明,500℃焙烧的P-25 TiO2光催化降解苯酚效率最高,适宜的晶相结构是500℃焙烧的P-25 TiO2光催化剂表现出较高催化活性的原因.苯酚在催化剂用量为2.0g/L、pH为7.0左右时降解较为适宜.HiO2对苯酚的光催化降解影响显著,在溶液中加入少量H2O3可大幅度提高光催化降解苯酚效率.  相似文献   

2.
二氧化钛膜及其改性膜光催化降解亚甲基蓝的研究   总被引:7,自引:0,他引:7  
采用溶胶-凝胶法制得锐钛型二氧化钛薄膜,研究了亚甲基蓝在该膜上的光催化降解初始速率与溶液初始pH值、外加电子捕获剂H2O2和外加空穴捕获剂CH3OH的关系,结果表明:投加TiO2膜光催化氧化亚甲基蓝的初始反应速率为0.012min^-1大于未投加TiO2薄膜的光氧化初始反应速率0.007min^-1.当pH为12.9,H2O2和CH3OH加入量分别为8.4mmol/L,5.6mmol/L时初始反应速率最大,所制的膜随使用次数的增加活性变化不显著,加入Fe2O3和V2O5制得复合的半导体膜提高了反应活性。  相似文献   

3.
介绍了以钛酸丁酯为主要原料的溶胶~凝胶法(Sol-Gel)制备TiO2光催化剂的过程,提出了较为理想的制备方法。探讨了工艺条件对催化降解效果的影响。结果表明,蜂窝陶瓷表面浸涂5层TiO2催化膜,经500℃焙烧,具有良好的光催化活性;H2O2、Fe“、光照时间、TiO2催化膜层数对邻氯苯酚去除率有不同程度的影响。  相似文献   

4.
利用溶胶-凝胶法制备TiO2薄膜光催化剂,考察掺杂铁、银离子改性与酸处理的TiO2薄膜以及有微量H2O2存在时光催化降解水杨酸的活性,并对改性薄膜光催化降解水杨酸的动力学进行研究.实验表明:改性后的TiO2薄膜光催化剂的活性均有不同程度的提高,其中体相掺铁和酸改性的TiO2薄膜光催化活性最高,并且改性的TiO2薄膜降解水杨酸过程符合一级反应;微量的H2O2存在使TiO2光催化降解效率明显提高.  相似文献   

5.
光降解用WO_3-TiO_2复合光催化剂   总被引:7,自引:1,他引:7  
用溶胶 凝胶法制备了纳米WO3 TiO2复合薄膜型光催化剂·利用该薄膜对罗丹明B溶液的光催化降解作用,考察了钨酸盐种类及其掺杂量、涂膜层数、溶解氧、焙烧温度、焙烧时间、基体材料等因素对光催化活性的影响·结果表明,钨酸铵加入量x(W)=1 5%、多孔钛片为基质,涂覆9层、500℃下焙烧1h得到的WO3 TiO2薄膜型复合光催化剂活性最高,其光催化活性较纯TiO2光催化剂提高1 5倍·该温度下多孔钛片负载的TiO2为锐钛矿型·  相似文献   

6.
ZnFe_2O_4/TiO_2薄膜的制备及其可见光活性的研究   总被引:1,自引:0,他引:1  
徐杰  鄂磊  康艳茹 《天津科技》2010,37(1):19-21
通过溶胶-凝胶法,结合浸渍-提拉工艺,制备了具有可见光活性的ZnFe2O4/TiO2薄膜,拓展了TiO2光谱响应范围,实现可见光活性。以一定浓度的甲基橙溶液为目标污染物,分别讨论了掺杂量、不同热处理温度等因素对光催化活性的影响,寻求较佳的光催化薄膜工艺参数。甲基橙溶液的降解结果表明掺杂后光催化剂的可见光光催化活性有所提高。另外,通过XRD和紫外-可见吸收光谱分析,初步探讨了光催化剂降解有机物的机理及其影响因素。  相似文献   

7.
采用溶胶凝胶法制备出ITO导电玻璃负载的TiO2薄膜光催化剂.利用XRD、Raman和SEM等手段对催化剂进行表征,结果表明:经500℃焙烧1h的TiO2/ITO薄膜光催化剂,以锐钛矿晶型存在;镀膜4次的TiO2薄膜表面均匀,对紫外光吸收强烈.乙酸的降解实验表明:TiO2/ITO薄膜与等负载量的TiO2粉末相比具有较高的光催化活性.  相似文献   

8.
TiO2/ACF光催化降解水中苯酚的研究   总被引:4,自引:0,他引:4  
研究了TiO2/ACF光催化剂的制备与表征,并对催化剂的活性以及光源种类和H2O2对TiO2/ACF光催化降解苯酚的影响进行了研究,结果发现:以涂覆法制得的TiO2/ACF光催化剂在废水处理方面有其独特的优点;添加少量H2O2和采用短波长光源均有利于苯酚的降解;254nm和365nm光催化降解苯酚的机理不同。  相似文献   

9.
掺铜TiO2的制备及其光催化降解铝试剂1的研究   总被引:5,自引:1,他引:4  
采用sol-gel法和高温灼烧制备了掺杂不同量的Cu^2 的TiO2/glass膜及纳米TiO2颗粒.研究了其对铝试剂的光催化降解过程,并由紫外吸收光谱对降解的中间产物进行了初步探讨.结果表明掺杂量为0.07%的Cu^2 时,光催化活性最佳.结合压电传感技术在线检测了不同气体氛围对TiO2光催化剂催化效果的影响,定量说明O2有利于光催化,而N2对其有抑制作用.  相似文献   

10.
综述了近年来TiO2粉体及薄膜光催化剂的制备方法,及光催化在环境净化和其它方面的应用进展,展望了TiO2光催化剂的发展研究方向。  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<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   

20.
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