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胶体晶体模板法制备三维有序排列的大孔SiO2材料 总被引:3,自引:0,他引:3
将粒径为480 nm的聚苯乙烯微球离心组装为胶体晶体模板,以正硅酸乙酯为硅源配制SiO2溶胶并填充到模板间隙,原位形成凝胶,最后通过焙烧去除模板,得到三维有序大孔(3DOM)SiO2。通过SEM检测,大孔以六方有序的方式排列,其孔径及孔径收缩率分别为360 nm和25%。大孔之间由小窗口连通,构成内部三维交联的大孔网络。低温N2吸附测试表明,大孔孔壁上存在中孔孔隙,其中在3~4 nm有一集中的孔分布。XRD显示,制备的3DOM材料由无定形SiO2组成。 相似文献
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以260 nm的聚苯乙烯胶体微球组装的胶体晶体作为模板,采用硝酸铝为原料制备了γ晶相的三维有序大孔(3DOM)Al2O3。首先将Al(NO3)3.9H2O溶解在体积分数70%的甲醇溶液中并填充到胶体晶体模板中,然后取出模板室温干燥,再用质量分数10%的稀氨水浸泡并干燥,最后经550℃焙烧3 h得到3DOMAl2O3。所得材料具有三维有序的大孔孔道,大孔之间由小窗口连通,构成内部交联的大孔网络。3DOMAl2O3孔壁由10 nm左右的Al2O3纳米粒子组成,形成丰富的介孔孔隙,并使材料构成大孔/介孔多级孔道体系,材料的BET比表面积达到315 m2/g。 相似文献
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以自然沉积的聚苯乙烯(PS)胶体晶体为模板,分别以正硅酸乙酯(TEOS)的醇盐溶液和溶胶溶液为前驱体对PS模板进行填充,通过煅烧除去模板,得到了三维有序大孔(3DOM) SiO2材料.由SEM照片观察发现,当以TEOS的醇盐溶液为前驱体时,获得的3DOM SiO2结构不易控制,缺陷较多.而以TEOS的溶胶溶液为前驱体时获得的3DOM SiO2结构良好,孔径大小均匀,排列整齐,可以看成是PS模板的逆复制,说明前驱体溶液的选择对3DOMSiO2材料的微观结构有显著的影响.XRD分析显示,制备的3DOM SiO2孔壁为无定形结构. 相似文献
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以聚苯乙烯(PS)微球为模板,氧化锡(SnO2)纳米晶为骨架,采用颗粒模板法成功制备了贯通有序大孔SnO2气敏材料。改变PS微球的粒径,可以调节大孔SnO2气敏材料的大孔孔径,本文以平均粒径约284nm和356nm的PS微球制备了大孔孔径分别约为200nm和260nm的贯通有序大孔SnO2气敏材料。对制备的样品进行了热重、X射线衍射、扫描电子显微镜和氮气吸附脱附分析。结果表明:大孔排列高度有序,孔道贯通,孔壁由SnO2纳米晶构成。制备的大孔SnO2气敏材料不仅具备大孔-介孔-微孔结构,而且具有大的比表面积,具备优异的气敏性能。气敏测试结果表明孔径为200nm和260nm的贯通有序大孔SnO2在280℃的工作温度下对300mL/L的乙醇气体的灵敏度为145、245,分别是无大孔SnO2纳米晶的2.2倍、3.7倍。 相似文献
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采用少皂乳液聚合法成功制备了单分散的聚苯乙烯微球,以微球自组装后的聚苯乙烯胶体晶体为大孔模板,铝溶胶为前驱体填充模板,干燥焙烧除去模板后制备了氧化铝载体。用激光粒度仪、扫描电镜、X射线衍射和氮气吸脱附对聚苯乙烯胶体晶体和氧化铝载体进行了表征。结果表明:少皂乳液聚合法制备的聚苯乙烯微球具有粒径较小(100~350 nm)、单分散性好(0.005)、收率高(约80%)等优点;自组装的胶体晶体呈规则有序排列,微球表面光滑洁净,并以此为模板成功制备了具有三维有序结构的、大孔孔径可调的氧化铝材料。 相似文献
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Qian Zhang 《Powder Technology》2011,212(1):145-150
TiO2 hollow spheres of controlled size were synthesized by combined acid catalytic hydrolysis and hydrothermal treatment, which involves the deposition of an inorganic coating of TiO2 on the surface of carbon spheres prepared by a hydrothermal method and subsequent removal of the carbon spheres by calcination in air. The obtained TiO2 hollow spheres were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and powder X-ray diffraction. The results revealed that the size and surface morphology of the TiO2 hollow spheres can be controlled by adjusting the concentration of the aqueous solution of glucose used to produce the template carbon spheres. Increasing the concentration of the glucose solution increased the average diameter of the TiO2 hollow spheres from 190 to 300 nm. TiO2 hollow spheres prepared using a glucose solution with a concentration of 0.7 mol/L are uniform in size with a diameter of 220 nm and shell thickness of 28 nm. The phenol removal rate of the sample prepared by calcination at 600 °C is 1.35 times higher than that of TiO2 made by the same method without using the carbon template. 相似文献
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Hao Wang Yan-wu Li Sung-june Cho Xiao-dong Li Dong-pyo Kim 《Microporous and mesoporous materials》2009,117(1-2):208-212
Three-dimensional long range ordered hollow Pt–Ru sphere assemblies were prepared using a sacrificial three-dimensionally ordered macroporous (3DOM) carbon template. Metallic salts, such as a mixture of RuCl3 with H2PtCl6 were infiltrated into the carbon template, and a reduced Pt–Ru phase was produced on the surface of the 3DOM carbon template by a borohydride reduction reaction. The sacrificial template was then burnt off in air at 650 °C. The diameter of the hollow Pt–Ru spheres could be tailored using a different pore size 3DOM carbon template. Assemblies with an outer diameter of 550 nm showed high BET surface area of 584.3 m2/g. In addition, a high hydrogen adsorption stoichiometry (>0.5 H/M) was obtained on the Pt–Ru sphere assemblies, which indicated that most of the metal atoms on the surface were exposed. 相似文献
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Large area ordered arrays of macroporous Cadmium Selenide (CdSe) nanostructure, which possesses high refractive index and negligible absorption in the visible spectrum critical for the realization of photonic band gaps, was prepared via colloidal templating by galvanostatic electrodeposition. This work investigates the effect of electrodeposition parameters on the macroporous CdSe nanostructure. Field Emission Scanning Electron Microscope (FESEM) images showed two and three dimensional porous structures, consisting of interconnected close-packed arrays of pores. For CdSe thin film of thickness less than 1/3 of the diameter of a polystyrene sphere, it showed a monolayer of circular pores. As for film thickness close to the diameter of the sphere, the pores adopted irregular rounded triangular shapes. When the film thickness was more than one layer of the colloidal polystyrene template, the pores were spherical and had the same diameter as the polystyrene spheres. X-ray Diffraction (XRD) showed that the CdSe films prepared had a cubic structure with nanometer grain size, which was smaller than the diameter of the template spheres as well as the diameter of the interconnected channels. A range of 45–70 nm thick CdSe films with > 90% optical transmittance showed that there was negligible absorption at wavelength of 750 nm. In addition, the CdSe thin film exhibited a band gap energy of 2.07 eV, blue-shifted from the characteristic 1.7 eV of CdSe. This blue-shift characteristic of the deposited CdSe film further indicated that it was nanocrystalline which is potentially useful in photonic applications. 相似文献
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Large area ordered arrays of macroporous Cadmium Selenide (CdSe) nanostructure, which possesses high refractive index and
negligible absorption in the visible spectrum critical for the realization of photonic band gaps, was prepared via colloidal
templating by galvanostatic electrodeposition. This work investigates the effect of electrodeposition parameters on the macroporous
CdSe nanostructure. Field Emission Scanning Electron Microscope (FESEM) images showed two and three dimensional porous structures,
consisting of interconnected close-packed arrays of pores. For CdSe thin film of thickness less than 1/3 of the diameter of
a polystyrene sphere, it showed a monolayer of circular pores. As for film thickness close to the diameter of the sphere,
the pores adopted irregular rounded triangular shapes. When the film thickness was more than one layer of the colloidal polystyrene
template, the pores were spherical and had the same diameter as the polystyrene spheres. X-ray Diffraction (XRD) showed that
the CdSe films prepared had a cubic structure with nanometer grain size, which was smaller than the diameter of the template
spheres as well as the diameter of the interconnected channels. A range of 45–70 nm thick CdSe films with > 90% optical transmittance
showed that there was negligible absorption at wavelength of 750 nm. In addition, the CdSe thin film exhibited a band gap
energy of 2.07 eV, blue-shifted from the characteristic 1.7 eV of CdSe. This blue-shift characteristic of the deposited CdSe
film further indicated that it was nanocrystalline which is potentially useful in photonic applications. 相似文献
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A newly developed route for the synthesis of hollow carbon nanospheres without introducing template under hydrothermal conditions
was reported. Hollow carbon nanospheres with the diameter of about 100 nm were synthesized using alginate as reagent only.
Many instruments were applied to characterize the morphologies and structures of carbon hollow nanospheres, such as XRD, TEM,
and Raman spectroscopy. The possible formation and growth mechanism of carbon hollow spheres were discussed on the basis of
the investigation of reaction influence factors, such as temperature, time, and content. The findings would be useful for
the synthesis of more materials with hollow structure and for the potential use in many aspects. The loading of SnO2 on the surface of carbon hollow spheres was processed, and its PL property was also characterized. 相似文献
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Macroporous FCC catalyst and macroporous HDS catalyst were prepared using polystyrene spheres as template. The size of the macropores can be tailored by controlling the size of template. The BET surface area and the pore volume of the macroporous catalysts are larger than those of catalysts prepared without template, and the more template used, the larger the surface area and pore volume obtained. When the same amount of template was used, the smaller diameter template produced a catalyst with larger surface area and pore volume. The increments in surface area and pore volume of the catalysts were greater than those predicted from the geometry of the template, indicating particle template could inhibit the shrinkage of the catalyst during drying. When used as heavy oil FCC catalysts and heavy oil HDS catalyst, the prepared macroporous catalysts are much more active than catalysts prepared without the template. 相似文献