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 468 毫秒
1.
采用溶胶凝胶-水热合成结合法制备铋氮共掺杂二氧化钛纳米催化剂.以酸性橙7(AO7)为目标污染物,研究Bi-N-Ti O2催化剂的可见光光催化活性,考察催化剂投加量、污染物初始浓度及p H值等条件对AO7脱色效率影响.结果表明:Bi-N-Ti O2光催化剂在可见光(400~750 nm)照射6 h后对AO7的去除率达到86.48%,比在同样条件下制备的单元素掺杂催化剂Bi-Ti O2(22.09%)、N-Ti O2(15.9%)以及Ti O2(11.89%)、P25(14.12%)等表现出更好的可见光响应特征;当催化剂投加量为1 g·L-1、AO7初始浓度为10 mg·L-1、反应液p H值为3时催化剂光催化降解AO7的脱色效果最好;且可见光下Bi-N-Ti O2催化剂具有一定的重复使用性和再生性能.  相似文献   

2.
制备了Dawson结构磷钨酸(H6P2W18O62.13H2O),通过UV-Vis及电化学方法分别对其结构和电化学性能进行了表征.以甲基橙溶液(MO)为模拟工业染料废水,研究Dawson结构磷钨酸在紫外光照射下催化剂的光催化性能.研究结果表明,在pH值2时,催化剂表现出较强的氧化还原能力;在优化条件下,即催化剂用量为1.5 g/L、甲基橙初始浓度为10 mg/L、紫外光照时间为120 min时,甲基橙降解率为93.83%.  相似文献   

3.
采用石墨烯/TiO_2复合材料对染料废水进行光催化降解.研究染料废水初始pH值、初始浓度、催化剂的加入量、不同系列染料(罗丹明B(rhodamine B,Rh B)、亚甲基蓝(methylene blue,MB)、甲基橙(methyl orange,MO))对石墨烯/TiO_2光催化性能的影响,结果表明石墨烯/TiO_2光催化降解染料废水的最佳条件:溶液初始p H值为6,染料废水初始浓度为25 mg/L,石墨烯/Ti O2为3 g/L,且60 min内罗丹明B溶液完全脱色.  相似文献   

4.
以乙酸钡(Ba(CH3COO)2)和结晶四氯化锡(SnCl4.5H2O)为原料、有机碱四甲基氢氧化铵(N(CH3)4OH)为矿化剂,采用共沉淀法制备BaSnO3纳米粒子,采用XRD、TG-DSC和IR等分析手段对样品的晶相和结构进行表征,并研究了其对甲基橙废水溶液的光催化降解性能.结果表明:在500℃条件下煅烧1 h制备出纯的立方相BaSnO3纳米晶光催化剂,对甲基橙有良好的光催化性能,当催化剂质量浓度为40 mg/L,反应时间为100 min时,降解率可达90%以上.  相似文献   

5.
采用酸法制备羟基氧化铁纳米粒子,以其为催化剂,以过氧化氢为氧化剂,进行甲基橙的催化降解反应并推断反应机理。研究催化剂加入量、氧化剂浓度、反应温度和反应p H等对甲基橙降解率的影响,并对催化剂的溶铁量进行测量。研究结果表明:当H2O2浓度为0.23 mmol/L,催化剂质量浓度为0.28 g/L,p H为2.54时,在60℃下反应30 min,质量浓度为9.41 mg/L的甲基橙的降解率为97.3%。在催化反应过程中发挥主要作用的OH?由均相催化反应和非均相的表面催化反应提供。由催化剂溶铁而进行的均相催化反应在甲基橙降解过程中可能发挥了重要作用。  相似文献   

6.
以锐钛矿TiO2粉末为原料,采用水热法合成了Ti02纳米棒,并利用X射线粉末衍射仪(XRD)、透射电子显微镜TEM等手段对产品进行了表征.以甲基橙为模拟染料废水,TiO2纳米棒为催化剂,在紫外光照条件下考察TiO2纳米棒的投加量、甲基橙的初始浓度、光照时间、溶液pH值及重复使用次数对甲基橙光降解效率的影响。实验结果表明:TiO2纳米棒的投加质量浓度为0.2g/L,甲基橙初始浓度为10mg/L,pH为5~6;光催化反应3h后,甲基橙的降解率可达96.5%;TiO2纳米棒重复使用5次后,甲基橙的降解率仍然可达85.6%.  相似文献   

7.
以钛酸四丁酯为前驱体,利用溶胶-凝胶法制备了不同掺铁量的改性纳米Ti02光催化剂,用XRD表征了其结构特征,并以甲基橙为目标降解物,评价了改性后纳米TiO2的光催化性能。结果:掺铁质量分数为0.03%的TiO2光催化活性最高;当甲基橙的初始浓度为16mg/L、掺铁0.03%TiO2的投加量为1.2g/L、pH值为3时,40w紫外灯照射210min,甲基橙的去除率高达95%以上。  相似文献   

8.
以硝酸锶(Sr(NO3)2)和结晶四氯化锡(SnCl4.5H2O)为原料,用共沉淀法制备钙钛矿型SrSnO3纳米粒子,并采用XRD、TG-DSC、IR等分析手段对样品的形成过程、物相和结构进行表征.以甲基橙溶液为目标降解物,研究了SrSnO3纳米粒子的光催化性能.结果表明:反应过程中存在着明显的晶型转化,反应温度是制备高纯SrSnO3纳米粒子的关键.反应温度为500℃时,SrSnO3纳米粒子极易形成;随着反应时间的延长,粒子尺寸不断增大.SrSnO3纳米粒子对甲基橙溶液有明显的光催化降解作用,当催化剂浓度为40 mg/L,反应时间为120 min时,降解率可达92.5%.  相似文献   

9.
采用溶胶-凝胶法制备钌掺杂型二氧化钛,并用海藻酸钠固定化制成凝胶微球.以甲基橙为模拟染料废水,太阳光作为能源,研究钌离子的掺杂量、催化剂用量、甲基橙初始浓度和光照时间对掺杂二氧化钛的光催化性能的影响.结果表明,掺杂钌能明显改善二氧化钛的可见光催化性质.钌掺杂质量分数为1.5%,催化剂用量为3.0 g/L,甲基橙初始浓度20.0 mg/L条件下,染料溶液的降解率达90%.  相似文献   

10.
采用水热合成技术和原位调控技术,以富含羟基组分的甘油物质丙三醇作为催化剂的结构导向剂,可控合成高可见光活性的α-Fe2O3纳米粒子,并进一步制备出形貌结构可控的α-Fe2O3/石墨烯可见光复合催化剂.利用TEM、XPS、XRD等对复合材料进行表征,考察其在可见光条件下降解水中甲基橙(MO)的效能,并对光催化氧化机制进行初步探讨.结果显示,随着催化反应时间的增加,甲基橙的降解率不断增大.在溶液p H值为2、催化剂投加量为0. 1 g时,甲基橙降解率最高;无机盐离子对降解过程存在抑制作用,Na3PO4的抑制效果最显著.  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.
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