TY - JOUR
T1 - A comparison of mixed phase titania photocatalysts prepared by physical and chemical methods
T2 - The importance of the solid-solid interface
AU - Li, Gonghu
AU - Chen, Le
AU - Graham, Michael E.
AU - Gray, Kimberly A.
PY - 2007/9/17
Y1 - 2007/9/17
N2 - Mixed phase titania photocatalysts, such as Degussa P25, typically show higher photocatalytic activity than pure phase titania, as reported by many researchers. Our previous experimental results indicate that the solid-solid interface is a key factor in enhancing the photocatalytic reactivity of mixed phase titania and may be the location of catalytic "hot spots". In this study, titania photocatalysts consisting of varying amount of anatase and rutile phases are prepared by reactive dc magnetron sputtering and by a modified sol-gel method. These titania materials are characterized with a variety of techniques and are tested in the photocatalytic degradation of acetaldehyde. Mixed phase titania thin films prepared by magnetron sputtering have a high density of anatase-rutile interfaces and display the highest photocatalytic activity among the catalysts tested. Studies by electron paramagnetic resonance spectroscopy show a unique distribution of charge trapping sites which are characteristic of the sputtered films. The role of anatase-rutile interface to separate charge and improve the photoactivity of mixed phase materials is discussed.
AB - Mixed phase titania photocatalysts, such as Degussa P25, typically show higher photocatalytic activity than pure phase titania, as reported by many researchers. Our previous experimental results indicate that the solid-solid interface is a key factor in enhancing the photocatalytic reactivity of mixed phase titania and may be the location of catalytic "hot spots". In this study, titania photocatalysts consisting of varying amount of anatase and rutile phases are prepared by reactive dc magnetron sputtering and by a modified sol-gel method. These titania materials are characterized with a variety of techniques and are tested in the photocatalytic degradation of acetaldehyde. Mixed phase titania thin films prepared by magnetron sputtering have a high density of anatase-rutile interfaces and display the highest photocatalytic activity among the catalysts tested. Studies by electron paramagnetic resonance spectroscopy show a unique distribution of charge trapping sites which are characteristic of the sputtered films. The role of anatase-rutile interface to separate charge and improve the photoactivity of mixed phase materials is discussed.
KW - Magnetron sputtering
KW - Photocatalysis
KW - Sol-gel
KW - Titania
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U2 - 10.1016/j.molcata.2007.05.017
DO - 10.1016/j.molcata.2007.05.017
M3 - Article
AN - SCOPUS:34548232736
VL - 275
SP - 30
EP - 35
JO - Journal of Molecular Catalysis A: Chemical
JF - Journal of Molecular Catalysis A: Chemical
SN - 1381-1169
IS - 1-2
ER -