High Cobalt Content Mesoporous Silicas
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- 作者：Jamal El Haskouri ; Saú ; l Cabrera ; Carlos J. Gó ; mez-Garcí ; a ; Carmen Guillem ; Julio Latorre ; Aurelio Beltrá ; n ; Daniel Beltrá ; n ; M. Dolores Marcos ; and Pedro Amoró ; s
- 刊名：Chemistry of Materials
- 出版年：2004
- 出版时间：July 13, 2004
- 年：2004
- 卷：16
- 期：14
- 页码：2805 - 2813
- 全文大小：191K
- 年卷期：v.16,no.14(July 13, 2004)
- ISSN：1520-5002
文摘
Silica-based MCM-41-like mesoporous materials with high cobalt content (
Si/Co 23) have been synthesized through a one-pot surfactant-assisted procedure from aqueoussolution using a cationic surfactant (CTMABr = cetyltrimethylammonium bromide) asstructural directing agent, and starting from molecular atrane complexes of Co and Si asinorganic hydrolytic precursors. This preparative technique allows optimizing the dispersionof the Co guest species in the silica walls. The mesoporous nature of the final materials isconfirmed by XRD, TEM, and N2 adsorption-desorption isotherms. They display unimodaland relatively narrow pore size distributions, whereas their pore array evolves from orderedhexagonal (H0) to wormhole-like (W) as the Co content increases. A careful spectroscopic(UV-visible and NMR) and magnetic study of these materials shows that, regardless of theSi/Co ratio, Co atoms are organized in well-dispersed, uniform CoO nanodomains (ca. 3 nm)partially embedded within the silica walls. These materials, which show superparamagneticbehavior, can be referred to as mesoporous CoO-MCM-41 nanocomposites.
Si/Co 23) have been synthesized through a one-pot surfactant-assisted procedure from aqueoussolution using a cationic surfactant (CTMABr = cetyltrimethylammonium bromide) asstructural directing agent, and starting from molecular atrane complexes of Co and Si asinorganic hydrolytic precursors. This preparative technique allows optimizing the dispersionof the Co guest species in the silica walls. The mesoporous nature of the final materials isconfirmed by XRD, TEM, and N2 adsorption-desorption isotherms. They display unimodaland relatively narrow pore size distributions, whereas their pore array evolves from orderedhexagonal (H0) to wormhole-like (W) as the Co content increases. A careful spectroscopic(UV-visible and NMR) and magnetic study of these materials shows that, regardless of theSi/Co ratio, Co atoms are organized in well-dispersed, uniform CoO nanodomains (ca. 3 nm)partially embedded within the silica walls. These materials, which show superparamagneticbehavior, can be referred to as mesoporous CoO-MCM-41 nanocomposites.