Papers by Keyword: Mesoporous

Abstract: In this paper, we report a simple strategy for fabricating mesoporous magnesium borate (2MgO·B₂O₃) microspheres. We employed sodium dodecyl sulfate (SDS) in one system, as a template for the controlled growth of mesoporous 2MgO·B₂O₃ microspheres. The products were characterized by XRD, SEM, TEM, EDS, N₂ sorption and FT-IR. SEM and TEM observations indicate magnesium borate products are composed of a large number of hollow microspheres, with diameters of 1.0~1.5 μm, which are in fact built from fibers with lengths of 100~150 nm. The N₂ sorption results show that the products have meso-structures. The average pore diameter is 27 nm. The BET surface area is about 53.03 m²/g, and the pore volume is 0.37 m³/g. It was found that SDS plays a key role for the formation of mesoporous structure. A possible mechanism was proposed to interpret the formation of the mesoporous structure. The mesopores will endow the hierarchical microspheres with novel application potentials.

Abstract: Mesoporous TiO₂ thin films have been prepared with so1-ge1 method by using tetrabutyl titanate(TBT) as precursor and PEG (Molecular weight 3000)as template．The XRD spectrum of the samples of the thin films indicated that the sample crystallized into anatase phase under the 500°C．And the photocatalytic degradation study of dioxins from MSW ash had been carried out. The result showed that the Mesoporous TiO₂ thin films with anatase phase had high photocatalytic efficiency and was in favor of the regeneration and reuse.

Abstract: TiO₂ nanostructures with a pure anatase phase were successfully synthesized using hydrothermal treatment of P25-TiO₂ nanoparticles. These nanostructures were characterized using transmission electron microscopy (TEM) and x-ray powder diffraction measurements. The dependences of reaction temperature and calcination temperature on titanate-anatase phase transformation and the morphology of TiO₂ nanostructures were also discussed. The results demonstrated that phase composition and particle morphology can be controlled by both the reaction and calcination temperatures.

Abstract: Mesoporous ZnO/SnO2 (Zn : Sn = 2 : 1) composite nanofibers with diameter of 49±6 nm and pore size of 6.7 nm were fabricated via the electrospinning technique. Their structure and morphology were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV–vis diffuse reflectance spectra (DRS) and nitrogen absorption-desorption isotherm analysis. The photocatalytic degradation rate of RhB dye by the mesoporous ZnO/SnO2 composite nanofibers was 0.051 min-1, which was more than two times and seven times of that by the pure ZnO (0.024 min-1) and pure SnO2 (0.007 min-1) nanofibers, respectively. The charge separation of electrons and holes was promoted and the recombination of the hole-electron pairs was reduced because of the coupling effect of ZnO and SnO2 in the grain-like composite nanoparticles, thus the quantum efficiency was increased. A schematic diagram of photocatalytic mechanism of mesoporous ZnO/SnO2 composite nanofibers was presented.

Abstract: After the invention of mesoporous material, the chiral mesoporous materials had been regarded as a hot research issue. Inspired by the chiral phenomenon, in this investigation, we presented several aspect of chiral mesoporous material from its first appearance, especially stated the template that could be used to prepare chiral mesoporous material, including chiral template and achiral template, besides, the different mechanisms and several distinguished scientists’ works were introduced, and some application of these material were introduced such as catalyst, HPLC stationary phases and many other fields.

Abstract: After the invention of mesoporous, the chiral mesoporous materials had been regarded a hot research issue. Inspired by the chiral phenomenon, in this investigation, we presented several aspect of chiral mesoporous from its first appearance, especially stated the template that could be used to prepare chiral mesoporous, including chiral template and achiral template, besides, the different mechanism of some distinguished scientists’ works were introduced, and some application of these material were introduced such as catalyst, HPLC stationary phases and many other fields.

Abstract: In this paper, mesoporous indium oxide has been synthesized by the hard template route from the SBA-15 silica template. The results characterized from XRD, and N₂ adsorption-desorption demonstrated that the synthesis can be controlled successfully in nanometer (meso-structure) scale. The obtained sample was investigated as humidity sensing material by coating on a ceramic plate, and the humidity sensing performance can be enhanced up to more than three orders of magnitude without any doping. Further testing proved that it is a promising humidity sensing material and can be widely used, and a possible mechanism was also provided.

Abstract: Mesostructured nickel phosphate was synthesized with urea as alkali by sol-gel method. The obtained material nominated as NiPO-3 was characterized by means of XRD, ICP, FT-IR, TEM, and N₂ adsorption. In contrast to mesoporous nickel phosphate NiPO-1 and NiPO-2 we reported before, NiPO-3 exhibits relatively longer nanotubes reached up to 400~600 nm. N2 adsorption shows that NiPO-3 possesses high BET surface area (345.8 m²g^-1) and pore volume (0.46 cm³g^-1). The catalytic performance of NiPO-3 showed that the total selectivity of epoxycyclohexane and hexadienol was as high as 83.38%.

Abstract: Micro- and mesoporous composite molecular sieves enable to achieve grades distribution of pore sizes and appropriate collocation of acidity,which have potential applications in catalysis and adsorption of large molecules.This review focus on some of the most recent results during the last decades.The techniques applied to synthesize different micro-mesoporous composite molecular sieves includes single template, dual template, crystallization of mesoporous walls, alkaline desilication, vapor-phase transport synthesis,and microwave radiation hydrothermal synthesis.

Abstract: New thiol modified mesoporous adsorbent with different pore sizes was synthesized by hydrothermal, with triblock copolymers pluronic (F127) and cetyltrimethyl ammonium bromide (CTMABr) functioned as the mixing template, 1,3,5-trimethylbenzene (TMB) functioned as pore-expanding agent. Adsorption performance of different pore sized mesoporous adsorbents was studied by treatment of Heavy metal Cu2+. Results showed that the optimum dosage was molar ratio of 1.5 between TMB and surfactant, and under that condition, the BET pore size was 6.554 nm and BET pore volume was 0.6134cm3/g. The adsorption of Cu2+ on mesoporous adsorbents fitted well to Redlich-Peterson isotherm equation, which indicated chemisorption was dominant in the process of heavy metal adsorption on the mesoporous adsorption and monomolecular layer adsorption took advantage. According to Langmuir equation, QL was 0.6210 mmol/g, and that demonstrated pore-expanding treatment could not only enlarge pore volume and diameter, but also effectively increase the contact area with heavy metals. Pore-expanded functionalized mesoporous silica could act as the optimal adsorbents for heavy metal adsorption.