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Fabrication and Characterization of Monodisperse Magnetic Porous Nickel Microspheres as Novel Catalysts.

Teng C, He J, Zhu L, Ren L, Chen J, Hong M, Wang Y - Nanoscale Res Lett (2015)

Bottom Line: The strategy involves impregnation of porous polymer microspheres with nickel precursors, calcination to remove the template, followed by thermal reduction.The unique porous nanostructured Ni microspheres possess catalytic activity and excellent recyclability, as demonstrated in the catalytic reduction of 4-nitrophenol to 4-aminophenol.The micropherical Ni catalysts could be easily separated either by an external magnetic field or by simple filtration.

View Article: PubMed Central - PubMed

Affiliation: Guangdong Provincial Key Laboratory of Nano-Micro Materials Research, School of Chemical Biology & Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.

ABSTRACT
A facile and efficient hard-templating strategy is reported for the preparation of porous nickel microspheres with excellent uniformity and strong magnetism. The strategy involves impregnation of porous polymer microspheres with nickel precursors, calcination to remove the template, followed by thermal reduction. The morphology, structure, and the property of the Ni microspheres were characterized by scanning electron microscopy, X-ray powder diffraction, N2 adsorption-desorption isotherms, thermogravimetric analysis, and magnetic hysteresis measurement. The obtained porous nickel microspheres were monodispersed with a particle size of 0.91 μm and crystallite size of 52 nm. Their saturation magnetization was much higher than that of Ni nanoparticles. The unique porous nanostructured Ni microspheres possess catalytic activity and excellent recyclability, as demonstrated in the catalytic reduction of 4-nitrophenol to 4-aminophenol. The micropherical Ni catalysts could be easily separated either by an external magnetic field or by simple filtration.

No MeSH data available.


TGA curve of the polymer template and polymer/Ni precursor composite microspheres
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Fig3: TGA curve of the polymer template and polymer/Ni precursor composite microspheres

Mentions: The nitrogen adsorption-desorption results of the microspheres are presented in Table 1, and an additional file shows the curves of N2 adsorption-desorption isotherms and pore size distributions in more detail [see Additional file 1]. The template microspheres have a specific surface area of 75 m2 · g−1 and pore volume of 0.38 cm3 · g−1 with a BJH pore size of 21 nm. The composite microspheres exhibited a lower surface area of 58 m2 · g−1 indicating that Ni precursors successfully occupied the pore voids of the polymer microspheres. After calcination, the polymer part of the composite microspheres was removed. The complete removal of the polymer template was confirmed by thermogravimetric analysis (TGA) of the composite microspheres (Fig. 3). The polymer/Ni precursor composite microspheres underwent three stages of weight loss, 25–250, 250–450, and 450–600 °C. The weight loss of 11.8 % below 250 °C could be ascribed to the gasification of small molecules such as adsorbed water and ethanol. Between 250 and 450 °C, the decomposition of polymer chain, decomposition/dehydration of nickel acetate, and crystallite formation in the composite microspheres led to a weight loss of 71.4 %, obviously lower than the 92.7 % of template polymer microspheres, due to the remaining of NiO species. Little weight loss (2.8 wt %) was observed for calcination above 450 to 600 °C. Therefore, calcination at 600 °C could assure thorough burning away of the polymer skeleton.Fig. 3


Fabrication and Characterization of Monodisperse Magnetic Porous Nickel Microspheres as Novel Catalysts.

Teng C, He J, Zhu L, Ren L, Chen J, Hong M, Wang Y - Nanoscale Res Lett (2015)

TGA curve of the polymer template and polymer/Ni precursor composite microspheres
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4593984&req=5

Fig3: TGA curve of the polymer template and polymer/Ni precursor composite microspheres
Mentions: The nitrogen adsorption-desorption results of the microspheres are presented in Table 1, and an additional file shows the curves of N2 adsorption-desorption isotherms and pore size distributions in more detail [see Additional file 1]. The template microspheres have a specific surface area of 75 m2 · g−1 and pore volume of 0.38 cm3 · g−1 with a BJH pore size of 21 nm. The composite microspheres exhibited a lower surface area of 58 m2 · g−1 indicating that Ni precursors successfully occupied the pore voids of the polymer microspheres. After calcination, the polymer part of the composite microspheres was removed. The complete removal of the polymer template was confirmed by thermogravimetric analysis (TGA) of the composite microspheres (Fig. 3). The polymer/Ni precursor composite microspheres underwent three stages of weight loss, 25–250, 250–450, and 450–600 °C. The weight loss of 11.8 % below 250 °C could be ascribed to the gasification of small molecules such as adsorbed water and ethanol. Between 250 and 450 °C, the decomposition of polymer chain, decomposition/dehydration of nickel acetate, and crystallite formation in the composite microspheres led to a weight loss of 71.4 %, obviously lower than the 92.7 % of template polymer microspheres, due to the remaining of NiO species. Little weight loss (2.8 wt %) was observed for calcination above 450 to 600 °C. Therefore, calcination at 600 °C could assure thorough burning away of the polymer skeleton.Fig. 3

Bottom Line: The strategy involves impregnation of porous polymer microspheres with nickel precursors, calcination to remove the template, followed by thermal reduction.The unique porous nanostructured Ni microspheres possess catalytic activity and excellent recyclability, as demonstrated in the catalytic reduction of 4-nitrophenol to 4-aminophenol.The micropherical Ni catalysts could be easily separated either by an external magnetic field or by simple filtration.

View Article: PubMed Central - PubMed

Affiliation: Guangdong Provincial Key Laboratory of Nano-Micro Materials Research, School of Chemical Biology & Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.

ABSTRACT
A facile and efficient hard-templating strategy is reported for the preparation of porous nickel microspheres with excellent uniformity and strong magnetism. The strategy involves impregnation of porous polymer microspheres with nickel precursors, calcination to remove the template, followed by thermal reduction. The morphology, structure, and the property of the Ni microspheres were characterized by scanning electron microscopy, X-ray powder diffraction, N2 adsorption-desorption isotherms, thermogravimetric analysis, and magnetic hysteresis measurement. The obtained porous nickel microspheres were monodispersed with a particle size of 0.91 μm and crystallite size of 52 nm. Their saturation magnetization was much higher than that of Ni nanoparticles. The unique porous nanostructured Ni microspheres possess catalytic activity and excellent recyclability, as demonstrated in the catalytic reduction of 4-nitrophenol to 4-aminophenol. The micropherical Ni catalysts could be easily separated either by an external magnetic field or by simple filtration.

No MeSH data available.