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金属和非金属共掺杂TiO_2催化剂光催化活性研究 总被引:2,自引:1,他引:1
采用溶胶-凝胶法制备了B、N和Ce共掺杂TiO2光催化剂,并用XRD、SEM等表征了其结构特征。以酸性大红染料为模型化合物,探索了其光催化性能,同时考察了制备条件对共掺杂TiO2催化剂活性的影响。结果表明,当B、N和Ce的原子为1∶2∶0.1时,光催化剂活性最大,大红染料的降解率达到98%。 相似文献
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《化工新型材料》2015,(8)
以轻质、多孔的膨胀珍珠岩(expanded perlite,EP)为载体,采用溶胶-凝胶法制备了一系列Fe、Tb单掺杂及共掺杂TiO2/EP漂浮型复合光催化剂,并通过XRD和SEM等分析方法对其结构进行表征,以罗丹明B溶液为目标降解物,研究所制备样品的光催化活性。结果表明:TiO2以纳米颗粒的形式牢固负载在EP薄片表面,内部具有蜂窝状多孔结构的EP为TiO2提供高浓度的三维降解环境;Fe、Tb共掺杂对纳米TiO2的晶型转变有较强的抑制作用,减小了晶粒粒径,有效提高了TiO2光催化活性,当Fe-Tb-Ti的摩尔比为0.02∶0.02∶1,催化剂用量为10g/L,罗丹明B溶液的降解效率最高,降解率可达89.2%。 相似文献
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选取Ni 2+掺杂量、冰醋酸、浓硝酸、煅烧温度设计正交实验,采用溶胶-凝胶法制备Ni 2+掺杂TiO2光催化剂,利用Raman、XRD、TEM等检测技术对其进行表征。通过与溶胶-凝胶法制备的纯TiO2纳米光催化剂进行对比,结果表明:Ni 2+掺杂TiO2光催化剂的TEM图像显示为球形粒子集合体,XRD图谱峰值降低,晶粒细化,拉曼光谱谱峰宽化、蓝移。以甲基橙模拟染料废水的降解率考察Ni 2+掺杂TiO2光催化活性,最佳条件下,Ni 2+掺杂TiO2对甲基橙的降解率为87.21%。 相似文献
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通过水解沉淀法和H2SO4浸渍干凝胶的方法,制备了具有可见光活性的超强酸化的Fe2O3-TiO2-N光催化剂。XRD测试结果表明,所制得的催化剂为锐钛矿型,且H2SO4处理显著抑制了晶粒的长大。UV-Vis分析表明,N、Fe掺杂样品相比纯TiO2有一定的红移,而浸渍硫酸的处理使样品的光吸收蓝移。原位红外的测试表明,H2SO4浸渍提高了催化剂的表面酸性,XPS测试说明了S以+6价存在于催化剂中。对丙烯酸的光降解试验表明,相比单独N掺杂的TiO2,所得的超强酸化的Fe、N共掺杂光催化剂活性提高了57%。 相似文献
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以钛酸四正了酯为先驱物,采用溶胶-凝胶法制备了纯TiO2和Fe3+掺杂的纳米TiO2(Fe3+/TiO2)光催化剂,并用XRD、UV-Vis等进行了表征,系统研究了煅烧温度、煅烧时间和Fe3+掺杂量对催化剂在自然光条件下光催化降解甲基橙性能的影响.结果表明,相同煅烧温度下,Fe3+/TiO2的粒径比纯TiO2的粒径小.制备纯TiO2和Fe3+/TiO2的最佳煅烧时间分别为4h和3h,最佳煅烧温度均为773K.适量掺入Fe3+可以显著提高纳米TiO2在自然光条件下的光催化降解活性,Fe3+/TiO2中Fe3+的最佳掺杂量为10.00%,相应的脱色效率为28.37%. 相似文献
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以钛酸四正丁酯为前驱体,采用溶胶-凝胶法常温制备稀土离子Ce4+掺杂的TiO2溶胶,用以光催化降解酸性藏青GGR,探究掺杂对TiO2溶胶光催化活性的影响.研究Ce4+掺杂量、pH、溶胶浓度和染料初始浓度对溶胶光催化活性的影响.结果表明:未掺杂TiO2溶胶粒径为29.7nm,随Ce4+掺杂量增加粒径逐渐降低至22.4nm,粒径的减小使得TiO2粒子比表面积加大,光催化活性提高.染料降解率随掺杂量增加而提高,当Ce4+的掺杂量超过1.0%时,降解率下降,说明过量的掺杂会抑制TiO2的光催化活性.溶胶pH会影响溶胶中TiO2晶型和带电情况,pH为1-2时溶胶光催化活性最高.溶胶浓度低光催化反应体系中TiO2受激发产生的电子和空穴少,染料降解率低.染料初始浓度高紫外光透过率小,光能利用率低,染料降解速度慢.当溶胶pH为1-2,溶胶浓度0.2mol·L-1,染料初始浓度59mg· L-1时,未掺杂TiO2溶胶对酸性藏青GGR的降解率为64.5%,摩尔掺杂比1.0%的Ce4+/TiO2对染料的降解率达90.2%.掺杂使TiO2的光催化活性提高了25.7%. 相似文献
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钇氮共掺杂纳米TiO_2光催化降解染料废水研究 总被引:1,自引:0,他引:1
以溶胶-凝胶法制备了钇、氮共掺杂纳米TiO2,对甲基橙染料废水进行了光催化降解实验。XRD、UV-VIS、FT-IR分析表明,500℃煅烧时得到的仍是锐钛矿型TiO2,晶粒变小;与单一的掺杂相比,共掺杂光催化活性有较大的提高,光响应范围得到很大拓展。Y3+、N的掺量分别为0.8%和0.5%时,在1.5h内甲基橙的降解率达到99.8%。 相似文献
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We have synthesized a variety of alkali-metal and ammonium fluorosulfatometallates (titanates, zirconates, and hafnates). The alkali fluorosulfatozirconates and fluorosulfatohafnates have been shown to exhibit efficient roentgenoluminescence (RL) in the UV through visible spectral region, with a maximum at 390–440 nm. Their RL spectra depend significantly on their composition (cation, anion, and water content), coordination of KF and K2SO4, and relative amounts of fluorine and SO4 groups. We have examined the effect of heat treatment on the RL of these compounds. The rubidium and cesium fluorosulfatozirconates Rb3Zr2F9SO4 · 2H2O, Cs2ZrF2(SO4)2 · 2H2O, Cs8Zr4F2(SO4)11 · 16H2O, and Cs2ZrF4SO4 offer the most efficient RL. 相似文献
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A. M. Grishin 《Journal of Engineering Physics and Thermophysics》2001,74(4):895-903
Basic definitions and concepts of the physicomathematical theory of natural catastrophes are given. Possibilities of mathematical modeling of natural and technogenic catastrophes are discussed in the context of the theory of heat and mass transfer and the mechanics of reacting media. The importance of taking into account conjugate heat and mass exchange in modeling catastrophes is emphasized. A formula for evaluating the probability of a collisional catastrophe is given. 相似文献
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Wiwanitkit V 《Hemodialysis international. International Symposium on Home Hemodialysis》2012,16(1):116; author reply 116-116; author reply 117
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Velev JP Jaswal SS Tsymbal EY 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2011,369(1948):3069-3097
The existence of multiple ferroic orders in the same material and the coupling between them have been known for decades. However, these phenomena have mostly remained the theoretical domain owing to the fact that in single-phase materials such couplings are rare and weak. This situation has changed dramatically recently for at least two reasons: first, advances in materials fabrication have made it possible to manufacture these materials in structures of lower dimensionality, such as thin films or wires, or in compound structures such as laminates and epitaxial-layered heterostructures. In these designed materials, new degrees of freedom are accessible in which the coupling between ferroic orders can be greatly enhanced. Second, the miniaturization trend in conventional electronics is approaching the limits beyond which the reduction of the electronic element is becoming more and more difficult. One way to continue the current trends in computer power and storage increase, without further size reduction, is to use multi-functional materials that would enable new device capabilities. Here, we review the field of multi-ferroic (MF) and magnetoelectric (ME) materials, putting the emphasis on electronic effects at ME interfaces and MF tunnel junctions. 相似文献
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Garny A Nickerson DP Cooper J Weber dos Santos R Miller AK McKeever S Nielsen PM Hunter PJ 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2008,366(1878):3017-3043
We have, in the last few years, witnessed the development and availability of an ever increasing number of computer models that describe complex biological structures and processes. The multi-scale and multi-physics nature of these models makes their development particularly challenging, not only from a biological or biophysical viewpoint but also from a mathematical and computational perspective. In addition, the issue of sharing and reusing such models has proved to be particularly problematic, with the published models often lacking information that is required to accurately reproduce the published results. The International Union of Physiological Sciences Physiome Project was launched in 1997 with the aim of tackling the aforementioned issues by providing a framework for the modelling of the human body. As part of this initiative, the specifications of the CellML mark-up language were released in 2001. Now, more than 7 years later, the time has come to assess the situation, in particular with regard to the tools and techniques that are now available to the modelling community. Thus, after introducing CellML, we review and discuss existing editors, validators, online repository, code generators and simulation environments, as well as the CellML Application Program Interface. We also address possible future directions including the need for additional mark-up languages. 相似文献
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Yongkang Chen Mike Bacich Cory Nardin Albert Sitorus Mark M. Weislogel 《Microgravity science and technology》2005,17(4):14-24
The behavior of wall-bound drops and bubbles is fundamental to many natural and industrial processes. Key characteristics
of such capillary systems include interface shape and stability for a variety of gravity levels and orientations. Significant
solutions are in hand for axisymmetric pendent drops for a variety of uniform boundary conditions along the contact line with
gravity acting normal to a planar wall. The special case of a wall-bound drop or bubble that is also pinned at an edge (i.e.
a ‘wall-edge-bound’ drop) is considered here where numerical solutions are obtained for interface shape and stability as functions
of drop volume, contact angle, fluid properties, and uniform gravity vector. For a semi-infinite zero-thickness planar wall
(plate), a critical contact angle is identified below which wall-edge-bound drops are always stable. The critical contact
angle is computed as a function of the gravity vector. The numerical procedure, which makes no account for contact angle hysteresis,
predicts that such wall-edge-bound drops are unconditionally unstable for any gravity field with a component that is tangent
to the wall while inwardly normal to the edge. Select experiments are conducted that support the conclusions drawn from the
numerical results. 相似文献