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掺杂铁纳米TiO2的制备及其光催化性能研究 总被引:7,自引:3,他引:7
分别采用水热法和溶胶-凝胶法制备了纳米级TiO2和不同掺铁量的TiO2纳米粒子。通过纯TiO2和掺铁TiO2分别作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,溶胶-凝胶法掺杂铁离子可以有效地提高TiO2光催化活性,而水热法掺杂铁使TiO2的光催化活性明显降低。Fe/TiO2摩尔比为0.01%~0.1%,随掺杂量的增大,TiO2光催化活性逐渐降低。 相似文献
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采用溶胶——凝胶法制备不同掺铁量及不同pH值下的一系列纳米TiO2光催化剂,对模拟活性艳红X-3B染料废水进行降解,对其光催化活性进行研究。实验表明:Fe3+-TiO2比纯纳米TiO2具有更好的催化活性,且Fe3+最佳掺杂量为0.05%,最佳制备pH值为4,最佳用量为1.2g/L。 相似文献
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Fe_2O_3/FeVO_4新型光催化剂的制备及光催化性能 总被引:3,自引:1,他引:3
采用液相沉淀法制备新型FecO2/FeVO4光催化剂,研究不同Fe掺杂量和煅烧温度对Fe2O3/FeVO4光催化活性的影响.以甲基橙水溶液为光催化降解对象,考察掺杂后的样品在紫外和可见光作用下的光催化活性.结果表明:当Fe/V摩尔比为1.01:1,750℃煅烧4h制得的样品光催化活性最好,较纯FeVO4提高19%左右.实验确定了样品光催化甲基橙溶液的最佳投加量为4 g/L,100 min内对甲基橙溶液的脱色率达到82%.同时样品具有很好的重复利用性,循环使用5次后,样品的光催化效率仍能保持在80%左右. 相似文献
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以钼酸铵、硝酸铋和硝酸铁为原料,采用水热/溶剂热法合成了铁掺杂的钼酸铋光催化剂,用X-射线粉末衍射、扫描电镜及紫外-可见吸收光谱等进行表征,并以罗丹明B为模型污染物,考察了纳米钼酸铋对罗丹明B溶液的光催化降解活性;以噻吩作为典型的含硫污染物,评价样品的光催化氧化脱硫活性。结果表明,Fe元素掺杂导致Bi2 MoO6的尺寸下降,比表面积增大;Fe掺杂,Bi2 MoO6吸收边发生红移;光催化活性与Fe元素的掺杂浓度有关,当掺杂量为0.5%时,活性最高;Fe掺杂Bi2MoO6对模拟汽油具有较好的脱硫活性,模拟可见光照射3 h,可使用模拟汽油的硫含量降低至70μg/g以下,脱硫率达到89%。 相似文献
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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分别做光催化荆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。 相似文献
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应用水热技术制备了二元Ni2+-Fe3+-CO23- LDHs和三元Co2+-Ni2+-Fe3+-CO32- LDHs,以十二烷基磺酸根离子作为插层客体,通过离子交换反应在酸性溶液中实现了十二烷基磺酸根插层Ni2+-Fe3+ LDHs和Co2+-Ni2+-Fe3+-LDHs。十二烷基磺酸根在Ni2+-Fe3+LDHs层间出现了2种空间导向和排列:即十二烷基磺酸根以单层垂直方向排布和以双层垂直方向排布在层间;十二烷基磺酸根在三元组分Co2+-Ni2+-Fe3+-LDHs层间只有一种空间排列方式,即十二烷基磺酸根以单层垂直方向排布于Co2+-Ni2+-Fe3+-LDHs层间。 相似文献
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The partition coefficients of ethylene between hydrate and vapor for methane + ethylene + water and methane + ethylene + SDS + water systems 总被引:1,自引:0,他引:1
The hydrate formation of CH4+C2H4 mixture was studied experimentally in two different cases, with and without the presence of sodium dodecyl sulfate (SDS) in water. The results manifested that the presence of SDS could not only accelerate the hydrate formation process, but also increase the partition coefficient of ethylene between hydrate and vapor drastically. The partition coefficients of ethylene between hydrate and vapor for methane + ethylene + water with the presence of 500 ppm SDS in water were then systematically measured. The experimental temperature ranged from 273.15 to 278.15 K, the pressure ranged from 2.5 to 5.5 MPa, the initial gas-liquid volume ratio ranged from 95 to 240 standard volumes of gas per volume of liquid, and the mole percentage of ethylene in feed gas mixture ranged from 5.28% to 79.36%. The results demonstrated that ethylene could be enriched in hydrate phase and partition coefficients were increased with the presence of SDS in water. This conclusion is of industrial significance; it implies that it is feasible to recover ethylene from gas mixture, e.g., various kinds of refinery gases or cracking gases in ethylene plant, by forming hydrate. 相似文献
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研究了Na+-Ca2+-Mg2+与钠型斜发沸石和NH4+-Ca2+-Mg2+与铵型斜发沸石的离子交换平衡,分别测定出2个体系的离子交换平衡数据,并利用三维坐标绘制出三元离子交换平衡等温面,计算出改型沸石对体系中离子的分离因数. 结果表明,在Na+-Ca2+-Mg2+溶液体系中,Na+的分离因数>10,Ca2+的在0.4~10之间,Mg2+的小于0.4,斜发沸石离子交换顺序为Na+>Ca2+>Mg2+,且温度升高Ca2+和Mg2+的交换能力增强,而低温则有利于沸石对Na+的选择;在NH4+-Ca2+-Mg2+溶液体系中,NH4+的分离因数>15,Ca2+的在0.2~1.5之间,Mg2+的小于0.2,斜发沸石离子交换顺序为NH4+>Ca2+>Mg2+,且温度升高Ca2+和Mg2+的交换能力增强,NH4+的选择性降低. 相似文献
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W. E. Blake J. Randle 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1967,17(12):358-360
Very dilute solutions containing zinc sulphate, sodium and sulphuric acid were passed down a column of Zeo-Karb 225 cation-exchange resin, and the volume at which zinc first appeared in the effluent (breakthrough volume), together with the volume at which the concentration of zinc in the effluent became equal to its concentration in the influent (equivalent volume), were determined. 相似文献
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采用电动势法测定了HCl+NaCl+DMSO+H_2O体系在298.15~318.15K范围内,总离子强度分别恒定在I=0.1,0.2,0.5mol·kg~(-1)情况下的HCl的活度系数。应用最小二乘法拟合,表明HCl的活度系数遵守Harned规则。从粒子间微观相互作用出发阐明了Harned参数α_A的物理意义,并给出了α_A与温度和溶液离子强度之间的关系。 相似文献
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卤代硅烷的相平衡数据为硅烷生产所需,而这方面的研究又较缺乏,尤其是甲基乙烯基二氯硅烷生产中所需的汽液相平衡数据尚未见报道.今用新型泵式沸点仪测定了常压(101.325 kPa)下甲基二氯硅烷 甲基三氯硅烷 二甲基二氯硅烷 苯四元系及其四个三元体系和六个二元体系在不同液相组成时的泡点.由所测的二元系数据,用过量自由焓Q函数间接法推算了与之平衡的汽相组成.再用最小二乘法求出二元体系的最佳配偶液相活度系数模型参数.所得的六组最佳二元系Wilson模型参数符合热力学一致性,并用于该体系三元和四元系汽液相平衡数据的预测,将计算的泡点与实验测得的泡点作了比较,其拟合精度良好,关联结果令人满意,硅烷二元系、多元系的热力学模型及VLE数据可为该体系的分离设计提供必要的理论依据. 相似文献
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A chemical model,based on Pitzer activity coefficient model,is developed with a speciation approach to describe the solubility and chemistry of nesquehonite in concentrated chloride solutions.The chemical equilibrium constants for nesquehonite and aqueous species,i.e.0 3 MgCO,3 MgHCO,and MgOH +,are precisely calculated as a function of temperature according to the Van’t Hoff equation by use of standard Gibbs free energy,standard formation enthalpy and heat capacity.The most recent solubility data are regressed to obtain new Pitzer parameters with good agreement.The predictive ability of the new model is improved significantly in comparison with previous models.The behavior of speciation chemistry for nesquehonite in various chloride media is explained through this modeling work on the basis of the 2 3 Mg /CO bearing species distribution,activity coefficient and pH changes. 相似文献
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Erevan. Translated from Fizika Goreniya i Vzryva, Vol. 26, No. 5, pp. 33–36, September–October, 1990. 相似文献
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利用尿素回流法合成Ni2+-Mg2+-Al3+-LDHs,Ni2+-Mg2+-Al3+-LDHs层状材料经300 ℃焙烧后,以焙烧产物作为前驱体,通过焙烧重组法将磷钨杂多酸成功引入Ni2+-Mg2+-Al3+-LDHs层中,制备磷钨杂多酸插层Ni2+-Mg2+-Al3+-LDHs复合材料。 相似文献
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Abbasali Arabi Jafar Mahmoudi Hamid Saradar Ahmad Jafarzade Mahdiyar Ghasemi 《Korean Journal of Chemical Engineering》2011,28(3):917-922
The experimental liquid-liquid equilibrium (LLE) data for six ternary systems containing (chloroform+propionic acid+water),
(chloroform+acetic acid+water), (diethyl ether+propionic acid+water), (diethyl ether+acetic acid+water), (trichloroethylene+propionic
acid+water) and (trichloroethylene+acetic acid+water) were measured at 288.15 K and at atmospheric pressure. An accurate and
simple titration method was used for determining of the concentration of carboxylic acid in the both liquid phases at equilibrium.
The reliability of the experimental tie-line data was confirmed by using the Othmer-Tobias correlation. The distribution coefficients
and selectivity factors were presented to evaluate the efficiency of the solvents for extraction of carboxylic acid from water.
The results show that chloroform and diethyl ether are satisfactory solvents for extraction of carboxylic acids from water.
Trichloroethylene separates propionic acid from water; however, it cannot be used as a solvent for separation of acetic acid. 相似文献