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Self-arrangement of nanoparticles toward crystalline metal oxides with high surface areas and tunable 3D mesopores.

Lee HI, Lee YY, Kang DU, Lee K, Kwon YU, Kim JM - Sci Rep (2016)

Bottom Line: We demonstrate a new design concept where the interaction between silica nanoparticles (about 1.5 nm in diameter) with titania nanoparticles (anatase, about 4 nm or 6 nm in diameter) guides a successful formation of mesoporous titania with crystalline walls and controllable porosity.At an appropriate solution pH (~1.5, depending on the deprotonation tendencies of two types of nanoparticles), the smaller silica nanoparticles, which attach to the surface of the larger titania nanoparticles and provide a portion of inactive surface and reactive surface of titania nanoparticles, dictate the direction and the degree of condensation of the titania nanoparticles, resulting in a porous 3D framework.Further crystallization by a hydrothermal treatment and subsequent removal of silica nanoparticles result in a mesoporous titania with highly crystalline walls and tunable mesopore sizes.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Sungkyunkwan University, Suwon, 440-746, Republic of Korea.

ABSTRACT
We demonstrate a new design concept where the interaction between silica nanoparticles (about 1.5 nm in diameter) with titania nanoparticles (anatase, about 4 nm or 6 nm in diameter) guides a successful formation of mesoporous titania with crystalline walls and controllable porosity. At an appropriate solution pH (~1.5, depending on the deprotonation tendencies of two types of nanoparticles), the smaller silica nanoparticles, which attach to the surface of the larger titania nanoparticles and provide a portion of inactive surface and reactive surface of titania nanoparticles, dictate the direction and the degree of condensation of the titania nanoparticles, resulting in a porous 3D framework. Further crystallization by a hydrothermal treatment and subsequent removal of silica nanoparticles result in a mesoporous titania with highly crystalline walls and tunable mesopore sizes. A simple control of the Si/Ti ratio verified the versatility of the present method through the successful control of mean pore diameter in the range of 2-35 nm and specific surface area in the ranges of 180-250 m(2) g(-1). The present synthesis method is successfully extended to other metal oxides, their mixed oxides and analogues with different particle sizes, regarding as a general method for mesoporous metal (or mixed metal) oxides.

No MeSH data available.


Related in: MedlinePlus

Proposed formation mechanism of mesoporous titania by the action of silica nanoparticles on titania nanoparticles under different Si/Ti ratios: Si/Ti = 0 (A), Si/Ti = 0.75 (B), 0 < Si/Ti < 0.75 (C) and Si/Ti > 0.75 (D).
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f1: Proposed formation mechanism of mesoporous titania by the action of silica nanoparticles on titania nanoparticles under different Si/Ti ratios: Si/Ti = 0 (A), Si/Ti = 0.75 (B), 0 < Si/Ti < 0.75 (C) and Si/Ti > 0.75 (D).

Mentions: Herein, we describe a silica nanoparticle-assisted novel design concept for mesoporous titania that have all of the above-mentioned desirable features, i.e., crystalline framework, well developed controllable 3D mesoporosity and facile process (Fig. 1). The present synthesis strategy, based on facile sol-gel synthesis in the absence of expensive organic surfactant templates, enables a systematical control of the pore dimension, the wall thickness and the specific surface area, in the range of 2–35 nm, 3–6 nm and 180–250 m2 g−1, respectively. More importantly, as the products have crystalline walls, the pore properties are resistance to heat up to 700 °C, which may lead to many new applications of mesoporous materials. Moreover, the results demonstrate that the present design concept suggested for titania can be extended to other metal oxide or mixed oxides such as SnO2, TiO2-ZrO2 and TiO2-SnO2.


Self-arrangement of nanoparticles toward crystalline metal oxides with high surface areas and tunable 3D mesopores.

Lee HI, Lee YY, Kang DU, Lee K, Kwon YU, Kim JM - Sci Rep (2016)

Proposed formation mechanism of mesoporous titania by the action of silica nanoparticles on titania nanoparticles under different Si/Ti ratios: Si/Ti = 0 (A), Si/Ti = 0.75 (B), 0 < Si/Ti < 0.75 (C) and Si/Ti > 0.75 (D).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4759599&req=5

f1: Proposed formation mechanism of mesoporous titania by the action of silica nanoparticles on titania nanoparticles under different Si/Ti ratios: Si/Ti = 0 (A), Si/Ti = 0.75 (B), 0 < Si/Ti < 0.75 (C) and Si/Ti > 0.75 (D).
Mentions: Herein, we describe a silica nanoparticle-assisted novel design concept for mesoporous titania that have all of the above-mentioned desirable features, i.e., crystalline framework, well developed controllable 3D mesoporosity and facile process (Fig. 1). The present synthesis strategy, based on facile sol-gel synthesis in the absence of expensive organic surfactant templates, enables a systematical control of the pore dimension, the wall thickness and the specific surface area, in the range of 2–35 nm, 3–6 nm and 180–250 m2 g−1, respectively. More importantly, as the products have crystalline walls, the pore properties are resistance to heat up to 700 °C, which may lead to many new applications of mesoporous materials. Moreover, the results demonstrate that the present design concept suggested for titania can be extended to other metal oxide or mixed oxides such as SnO2, TiO2-ZrO2 and TiO2-SnO2.

Bottom Line: We demonstrate a new design concept where the interaction between silica nanoparticles (about 1.5 nm in diameter) with titania nanoparticles (anatase, about 4 nm or 6 nm in diameter) guides a successful formation of mesoporous titania with crystalline walls and controllable porosity.At an appropriate solution pH (~1.5, depending on the deprotonation tendencies of two types of nanoparticles), the smaller silica nanoparticles, which attach to the surface of the larger titania nanoparticles and provide a portion of inactive surface and reactive surface of titania nanoparticles, dictate the direction and the degree of condensation of the titania nanoparticles, resulting in a porous 3D framework.Further crystallization by a hydrothermal treatment and subsequent removal of silica nanoparticles result in a mesoporous titania with highly crystalline walls and tunable mesopore sizes.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Sungkyunkwan University, Suwon, 440-746, Republic of Korea.

ABSTRACT
We demonstrate a new design concept where the interaction between silica nanoparticles (about 1.5 nm in diameter) with titania nanoparticles (anatase, about 4 nm or 6 nm in diameter) guides a successful formation of mesoporous titania with crystalline walls and controllable porosity. At an appropriate solution pH (~1.5, depending on the deprotonation tendencies of two types of nanoparticles), the smaller silica nanoparticles, which attach to the surface of the larger titania nanoparticles and provide a portion of inactive surface and reactive surface of titania nanoparticles, dictate the direction and the degree of condensation of the titania nanoparticles, resulting in a porous 3D framework. Further crystallization by a hydrothermal treatment and subsequent removal of silica nanoparticles result in a mesoporous titania with highly crystalline walls and tunable mesopore sizes. A simple control of the Si/Ti ratio verified the versatility of the present method through the successful control of mean pore diameter in the range of 2-35 nm and specific surface area in the ranges of 180-250 m(2) g(-1). The present synthesis method is successfully extended to other metal oxides, their mixed oxides and analogues with different particle sizes, regarding as a general method for mesoporous metal (or mixed metal) oxides.

No MeSH data available.


Related in: MedlinePlus