Specific surface area and three-dimensional nanostructure measurements of porous titania photocatalysts by electron tomography and their relation to photocatalytic activity

TY - JOUR

T1 - Specific surface area and three-dimensional nanostructure measurements of porous titania photocatalysts by electron tomography and their relation to photocatalytic activity

AU - Yoshida, K.

AU - Gai, P.L.

AU - Makihara, M.

AU - Tanaka, N.

AU - Aoyagi, S.

AU - Nishibori, E.

AU - Sakata, M.

AU - Boyes, E.D.

PY - 2011/4/1

Y1 - 2011/4/1

N2 - Various porous titania photocatalysts are analyzed three-dimensionally in real space by electron tomography. Shapes and three-dimensional (3D) distributions of fine pores and silver (Ag) particles (2 nm in diameter) within the pores are successfully reconstructed from the 3D data. Electron tomography is applied for measuring the specific surface area of the porous structures including open and closed porosity. Calculated specific surface areas of 22.8 m/g for a conventional sol-gel TiO2 sample and 366 m/g for a highly porous TiO2 sample prepared using the Pluronic P-123 self-assembly process are compared with those measured by the general BET method. The real-space surface measurement indicates that the highly porous TiO2 produced by the present method using block copolymers has a greater number of effective reaction sites for the degradation of methylene blue. Electron tomography shows a great potential to contribute considerably to the nanostructural analysis and design of such catalyst materials for photocatalysis. © 2011 Microscopy Society Of America.

AB - Various porous titania photocatalysts are analyzed three-dimensionally in real space by electron tomography. Shapes and three-dimensional (3D) distributions of fine pores and silver (Ag) particles (2 nm in diameter) within the pores are successfully reconstructed from the 3D data. Electron tomography is applied for measuring the specific surface area of the porous structures including open and closed porosity. Calculated specific surface areas of 22.8 m/g for a conventional sol-gel TiO2 sample and 366 m/g for a highly porous TiO2 sample prepared using the Pluronic P-123 self-assembly process are compared with those measured by the general BET method. The real-space surface measurement indicates that the highly porous TiO2 produced by the present method using block copolymers has a greater number of effective reaction sites for the degradation of methylene blue. Electron tomography shows a great potential to contribute considerably to the nanostructural analysis and design of such catalyst materials for photocatalysis. © 2011 Microscopy Society Of America.

KW - photocatalyst

KW - porous material

KW - electron tomography

KW - heterogeneity

KW - nanocatalysis

KW - TiO2

KW - BLOCK-COPOLYMER

KW - MICROSCOPY

KW - RESOLUTION

KW - WATER

KW - ADSORPTION

KW - ALIGNMENT

KW - CONTRAST

KW - FILMS

KW - GOLD

KW - STEM

UR - http://www.scopus.com/inward/record.url?scp=79957487397&partnerID=8YFLogxK

U2 - 10.1017/S1431927610094419

DO - 10.1017/S1431927610094419

M3 - Article

SN - 1431-9276

VL - 17

SP - 264

EP - 273

JO - Microscopy and Microanalysis

JF - Microscopy and Microanalysis

IS - 2

ER -