Papers by Keyword: Template Method

Abstract: Template method was used to prepare ordered mesoporous alumina, and with purchased γ-Al₂O₃ contrast. BET results showed that the specific surface area and average pore diameter of the mesoporous Al₂O₃ were 226.95 m².g^-1 and 3.91nm respectively, and with higher degree of order. XRD results showed that the cat-P catalyst with the carrier of prepared ordered mesoporous alumina hold small active component grains, which means better dispersion. H₂-TPR results showed that the SMSI effect of cat-P catalyst was stronger than that of cat-B. Stability tests showed that cat-P catalyst in 50h experiment showed high activity and stability, and the conversion of CH₄ and CO₂ were above 90% and 95% respectively among the reaction time, and the deactivation rate of CO₂ was 0.05%/h only. From TG-DTG curve could be seen that the deposition carbon on cat-P catalyst after 48h reaction was in whisker form, which did not cover the active sites and had little influence on the activity and stability of the catalyst.

Abstract: The fabrication of self-ordered semiconductor (TiO₂) and noble metal (Au) QDs arrays was successfully achieved by advanced nonlithographic template based method, namely using nanoporous alumina template. The emphasis was placed on the successful preparation of QDs arrays with the desired size, homogeneous distribution and optical (especially fluorescence) properties. Titania and gold QDs characterization by SEM, EDX and fluorescence spectroscopy was performed in order to verify their surface topography, chemical composition and emission properties in UV/VIS range of spectra, respectively. The surface biofunctionalization of QDs was realized via simple physical adsorption of glutathione tripeptide, which makes these arrays suitable for potential biosensing application, mainly in optical and electrochemical detection of biomolecules in vitro.

Abstract: In this study, Tin Oxide (SnO₂) inverse opal was fabricated by infiltrating SnO₂ sol-gel precursor solution into Poly Styrene (PS) spheres crystal template which was generated via evaporative deposition self-assembling, then was heat treating at 500°C for two hours in controlled atmosphere box furnaces. PS spheres crystal template was characterized by Scanning electron microscope and Ultraviolet-visible-near infrared absorption spectrometer. The SnO₂ inverse opal was characterized by Scanning electron microscope, Energy Diffraction Spectrum, X Ray Diffraction. The large-area, highly ordered SnO₂ inverse opal was achieved in this paper.

Abstract: Uniform growth of WO3 with macroscopic structures was successfully achieved by using carbon nanofibers (CNFs) as template. Field emission scanning electron microscopy (FE-SEM), coupled with X-ray diffraction (XRD) analysis confirmed the template effect and the existence of WO3 immobilized on the macroscopic silica fiber.

Abstract: Mesopores are essential to improve transport of molecules within porous network and to facilitate adsorption of larger molecules. Mesoporous activated carbons (MACs) were prepared by template synthesis and KOH activation, using modified coal tar pitch and nanosized silica as carbon precursor and imprinting template respectively. The influences of different activation conditions, including KOH/C mass ratio, activation temperature and activation time on the pore structure of MACs have been studied. The SBET, total volume and mesopore volume of the result MAC were 1356 m2/g, 0.910mL/g and 0.704 mL/g respectively, when activation conditions with KOH/C mass ratio was 3.6:1, activation temperature was 850°C and activation time was 2.0h. It is possible to control their pore structure by selecting appropriate activation conditions depending on the final application of the MACs.

Abstract: Waste cotton linters from textile industry were used as templates to be transformed as cotton fiber/SiO complex after sol impregnation, carbonization, carbon thermal reduction reaction, to prepare nanoSiC fibers and nanoparticles. The phase of final products were identified by XRD as β-SiC, and the diameter size of nanoSiC fiber was ranged as 20~100mm analyzed by SEM and TEM. Based on the thermodynamic analysis of each step in the thermal reduction on carbon / SiO composite to generate nanoSiC fibers, the nanoSiC fibers were generated by the vapor reaction between SiO and CO, and its growth mechanism was deduced as vapor-solid. For the reuse of cotton linter, thus the research provides a new solution.

Abstract: In this paper, a hollow sphere carbon nanotube (CNT) / polyaniline (PANI) composite was prepared by using the Fe₃O₄ as a template. At the same time, the pure PANI and CNT/PANI composite were obtained with same method without Fe₃O₄ template. The composition and the morphology of the obtained samples were characterized by the Fourier transform infrared spectroscopy and scanning electron microscope. And the electrochemical performances of the obtained materials were tested by the cyclic voltammogram, galvanostatic charging/discharging and cycle life testing. The results show that the obtained hollow sphere CNT/PANI composite have larger surface area than pure PANI and CNT/PANI composite for its hollow sphere structure. The obtained hollow sphere CNT/PANI composite have 185 F/g specific capacitance (in organic electrolyte), which is much more than those of the pure PANI and CNT/PANI composite (about 65 F/g, 152 F/g). The results also show that CNT have a great effect on the preparation of the hollow sphere CNT/PANI composite.

Abstract: A porous carbon has been prepared by template method using a natural clay mineral as template and furfuralcohol as carbon source. X-ray diffraction (XRD), nitrogen adsorption and scanning electric microscope (SEM) are used to investigate the composition, structure of pore and micro morphology of the samples. XRD analysis indicates that the templated carbon is amorphous. Nitrogen adsorption analysis indicates that the carbon is a microporous and mesoporous material. The specific surface area of the carbon is 302m²/g, and the external surface area is 158m²/g. The mesoporosity of the carbon is as high as 58.7%. SEM investigation indicates that the carbon has a squamiform shape.

Abstract: Four nanoporous carbons have been synthesized by using similar silica template method. The structural characterizations showed that the carbons retained ordered hexagonal or cubic pore structure expect for disordered CS41, which was prepared using MCM-41 as template. Nitrogen adsorptions at 77 K revealed that carbons with different pore size distribution, specific surface area and pore volume were obtained. The hydrogen adsorption capacity was measured by volumetric method, and the most promising candidate resulted to be microporous carbon CS41, which exhibited the highest H₂ uptake of 1.17 wt % at 77 K and 1 bar. The capacities of hydrogen adsorbed in the nanoporous carbons were correlated with specific surface area and microporous volume. The result demonstrated that the H₂ uptake in the carbons had essential relationship with volume of pores smaller than 1 nm.

Abstract: Novel netlike nano-TiO₂ was successfully prepared using polylatic acid (PLA) as a new template, and in particular, it was recyclable as photocatalyst. The products obtained at various temperatures were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and powder X-ray diffraction (XRD). Besides, the products have an excellent photocatalysis to methyl orange (MO) and methylene blue (MB).