TY - JOUR
T1 - Direct (one-step) synthesis of TiO2 and Pt/TiO2 nanoparticles for photocatalytic mineralisation of sucrose
AU - Teoh, Wey Yang
AU - Mädler, Lutz
AU - Beydoun, Donia
AU - Pratsinis, Sotiris E.
AU - Amal, Rose
PY - 2005/11
Y1 - 2005/11
N2 - TiO2 and Pt/TiO2 nanoparticles were made by a one-step flame spray pyrolysis (FSP) process that resulted in mostly anatase (69-85 wt%) powders with controlled specific surface area and crystallite size. These particles resulted in shorter half-lives for sucrose photomineralisation, up to 50% lower than Degussa P25. Co-precipitation of Pt on TiO2 during FSP increased the rutile content and slightly increased the specific surface area. Close control over Pt deposit size during this process was possible by varying the Pt concentration in the feed precursor. The dispersion of the Pt was high, 45-77% (at 4.0-0.1 atom% Pt) and corresponded to metal deposit size of 2.5-1.4 nm, respectively. An optimum photocatalytic activity was observed at 0.5 atom% Pt loading. At low Pt loading (0.1 atom% Pt), the activity was lower than that of FSP-made TiO2 since the high photocurrent density of the Pt deposits increased the electron-hole recombination. The deposit size was also too small to establish sufficient electrical contact for efficient interfacial charge transfer between the photocatalysts and sucrose. Additional studies on the photocatalytic mineralisation of sucrose under oxygen enriched conditions reaffirmed the postulation that both FSP-made TiO2 and improved Pt/TiO2 photocatalysts favoured a reductive pathway which was different and faster than the pathway followed when using Degussa P25 TiO2. The intricate relationship between photocatalyst characteristics and its performance is highlighted. © 2005 Elsevier Ltd. All rights reserved.
AB - TiO2 and Pt/TiO2 nanoparticles were made by a one-step flame spray pyrolysis (FSP) process that resulted in mostly anatase (69-85 wt%) powders with controlled specific surface area and crystallite size. These particles resulted in shorter half-lives for sucrose photomineralisation, up to 50% lower than Degussa P25. Co-precipitation of Pt on TiO2 during FSP increased the rutile content and slightly increased the specific surface area. Close control over Pt deposit size during this process was possible by varying the Pt concentration in the feed precursor. The dispersion of the Pt was high, 45-77% (at 4.0-0.1 atom% Pt) and corresponded to metal deposit size of 2.5-1.4 nm, respectively. An optimum photocatalytic activity was observed at 0.5 atom% Pt loading. At low Pt loading (0.1 atom% Pt), the activity was lower than that of FSP-made TiO2 since the high photocurrent density of the Pt deposits increased the electron-hole recombination. The deposit size was also too small to establish sufficient electrical contact for efficient interfacial charge transfer between the photocatalysts and sucrose. Additional studies on the photocatalytic mineralisation of sucrose under oxygen enriched conditions reaffirmed the postulation that both FSP-made TiO2 and improved Pt/TiO2 photocatalysts favoured a reductive pathway which was different and faster than the pathway followed when using Degussa P25 TiO2. The intricate relationship between photocatalyst characteristics and its performance is highlighted. © 2005 Elsevier Ltd. All rights reserved.
KW - Composites
KW - Flame spray pyrolysis
KW - Nanostructure
KW - Particle formation
KW - Photochemistry
KW - Titania
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UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-22244485017&origin=recordpage
U2 - 10.1016/j.ces.2005.05.037
DO - 10.1016/j.ces.2005.05.037
M3 - RGC 21 - Publication in refereed journal
SN - 0009-2509
VL - 60
SP - 5852
EP - 5861
JO - Chemical Engineering Science
JF - Chemical Engineering Science
IS - 21
ER -