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《山东化工》2021,50(13)
二氧化钛因具有优秀的抗化学和光腐蚀性能、高稳定性、价格低廉等特点被国际上普遍认为是最理想的光催化材料之一。但由于其存在禁带间隙较宽,光生载流子的的复合率高等缺陷导致其对光能利用率低。本文采用溶胶-凝胶法,以Ti(OC4H9)4为主要反应原料,NH4Cl、Fe Cl3、H3BO3作为掺杂剂,合成了Fe3+掺杂、B3+单掺杂; N、Cl、C共掺的改性Ti O2。通过样品表征,发现Fe3+改性催化剂在60min内对甲基橙解率高达87.5%,而B3+改性的Ti O2催化剂在60 min内对甲基橙解率只有80%。NH4Cl以浓HNO3为水解抑制剂制备的改性Ti O2催化剂要优于以浓HCl为水解抑制剂,其在60 min内对甲基橙降解率达到81.2%。 相似文献
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纳米光催化剂TiO_2/Fe_3O_4的制备及表征 总被引:2,自引:3,他引:2
采用两步法制备磁性负载纳米光催化剂TiO2/Fe3O4。首先用液相共沉淀法制备磁性纳米Fe3O4颗粒;然后用溶胶-凝胶法,以钛酸四正丁酯为先驱体,通过水解缩聚在Fe3O4纳米颗粒表面包覆TiO2层,得到易于磁分离回收的复合纳米光催化剂TiO2/Fe3O4,粒径大约为30 nm。利用TEM、XRD、FT-IR、VSM对Fe3O4和TiO2/Fe3O4的结构和性能进行了表征,结果表明,制备的Fe3O4为面心立方晶体(FCC)结构,具有超顺磁性;TiO2为锐钛矿相,包覆在Fe3O4的表面,形成了核-壳式结构的TiO2/Fe3O4复合光催化剂。 相似文献
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通过在NH4F+H2O的乙二醇溶液中阳极氧化铁箔,制备了纳米多孔结构的铁氧化物(Fe2O3–Fe3O4),然后在纳米多孔中电沉积镍,再经过400°C退火0.5 h,获得了镍与纳米多孔氧化铁的复合材料(Fe2O3–Fe3O4/Ni)。考察了电流密度和时间对镍沉积的影响。用扫描电镜、能谱仪、X射线衍射仪表征了复合材料的表面形貌、元素组成和物相,测试了其电化学性能并与未经电沉积镍的纳米多孔氧化铁(Fe2O3–Fe3O4)比较。结果表明,氧化铁由Fe2O3和Fe3O4组成。镀镍的最佳电流密度为2.0 m A/dm2,时间30 s。该纳米多孔Fe2O3–Fe3O4/Ni复合材料作为锂离子电池负极材料表现出更好的电化学性能──经过50次充放电循环后的放电比容量仍有438.3 m A·h/g,而Fe2O3–Fe3O4电极的放电比容量仅为110.6 m A·h/g。Fe2O3–Fe3O4/Ni电极的循环稳定性和倍率性能优异。 相似文献
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《硅酸盐学报》2016,(11)
以柠檬酸铁为铁源,采用真空浸渍法和高温热分解法,在天然埃洛石纳米管(Hal)内成功负载了Fe3O4纳米粒子复合材料(A-Hal/Fe3O4),验证产物对染料分子的吸附性能提升效果。通过X射线衍射仪、Fourier转换红外光谱、X射线光电子能谱仪、透射电子显微镜以及振动样品磁强计对A-Hal/Fe3O4复合磁性材料的组成、结构、形貌、磁性进行表征,通过紫外-可见光谱检测了A-Hal/Fe3O4复合材料吸附亚甲基蓝的性能。结果表明:Fe3O4纳米颗粒已成功负载在HNTs管内,但有少量的Fe3O4表面被氧化成磁赤铁矿(γ-Fe2O3),造成样品呈黄色;制备的A-Hal/Fe3O4复合磁性材料对5 mg/L的亚甲基蓝的吸附性能良好,30 min内的吸附脱色率为98.99%;回收后再次吸附,30 min内的吸附脱色率为94.14%;相比于埃洛石原矿,A-Hal/Fe3O4产物在30 min时的脱色率提升20%以上。同时,负载在埃洛石管内的Fe3O4纳米粒子的比饱和磁化强度(Ms)可以达到4.7(A·m2)/kg,通过外加磁场的吸引作用,成功将吸附了有机染料分子的复合材料从模拟废水中快速分离。 相似文献
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以FeCl3.6H2O和FeCl2.4H2O为原料,以水为介质,利用化学共沉淀法,常温下反应合成了Fe3O4纳米粒子,并进一步以Fe3O4纳米粒子为原料,采用原位聚合法分别在H2O和氯代1-丁基-3-甲基咪唑([BMIM]Cl)离子液体中合成了Fe3O4/聚苯胺(PANI)纳米复合粒子,用透射电子显微镜(TEM)、X射线衍射仪(XRD)、热分析仪(TG)、电导率仪、多功能振动样品磁强计对样品的形貌、结构和电磁性能进行了表征。结果表明:在这两种介质中都可以得到核壳型复合颗粒,但离子液体中合成的复合颗粒粒度小、分散性好且聚苯胺的结晶程度高。在离子液体中制备的复合材料与水中相同条件下制得的复合材料相比,电导率及磁性能均有提高。在离子液体中制备磁性导电复合材料是一种绿色高效的工艺。 相似文献
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以硫酸亚铁铵、葡萄糖和凹凸棒石为原料,采用一步水热法制备了凹凸棒石/Fe3O4/炭纳米复合材料,研究了氨水加入量和水热时间对材料微观结构、磁性能和吸附性能的影响,并与凹凸棒石、凹凸棒石/炭和凹凸棒石/Fe3O4进行对比分析。结果表明:由于氨水的加入,硫酸亚铁铵沉淀为纳米Fe3O4颗粒,负载于凹凸棒石表面;葡萄糖炭化为无定形炭负载于凹凸棒石表面。随着氨水加入量的增多和反应时间的延长,复合材料中Fe3O4含量相应增加,磁化率迅速增加。不同材料(凹凸棒石、凹凸棒石/炭、凹凸棒石/Fe3O4和凹凸棒石/Fe3O4/炭)的磁性能和吸附性能的对比分析表明:碳的负载有效改善了材料对有机污染物苯酚的吸附性能,Fe3O4则赋予材料磁性能。凹凸棒石/Fe3O4/炭对苯酚的去除率(57%)远高于未改性凹凸棒石,并可以从液相中磁分离。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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塔设备改造选型的分析 总被引:2,自引:0,他引:2
就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后,着重介绍一种新型塔板(导向梯形浮阀塔板)和一种新型填料(波环填料——乾隆帕克)。 相似文献
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In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997 相似文献