TY - JOUR
T1 - Shape-dependent surface energetics of nanocrystalline TiO2
AU - Park, Tae Jin
AU - Levchenko, Andrey A.
AU - Zhou, Hongjun
AU - Wong, Stanislaus S.
AU - Navrotsky, Alexandra
N1 - Copyright:
Copyright 2010 Elsevier B.V., All rights reserved.
PY - 2010/10/21
Y1 - 2010/10/21
N2 - We report the direct determination of surface enthalpies for nanophase TiO2 anatase with different morphologies derived from drop solution calorimetry in a molten sodium molybdate (3Na2O4MoO3) solvent at 702 °C. The energetics of surface hydration has been measured using a Calvet microcalorimeter coupled with a gas dosing system. The surface enthalpies of hydrated surfaces for anatase TiO2 nanoparticles, nanowires and sea-urchin-like assemblies are 0.51 ± 0.05, 1.07 ± 0.28, and 1.29 ± 0.16 J m-2, respectively, whereas those of anhydrous surfaces are 0.74 ± 0.04, 1.24 ± 0.28, and 1.41 ± 0.16 J m-2, respectively. The trend in TiO2, which shows higher surface enthalpies for more complex nanostructures, is consistent with that reported in ZnO. The shape-dependent surface enthalpy at the nanoscale level is discussed in terms of exposed surface structures. The enthalpies of hydration appear to be similar for all morphologies.
AB - We report the direct determination of surface enthalpies for nanophase TiO2 anatase with different morphologies derived from drop solution calorimetry in a molten sodium molybdate (3Na2O4MoO3) solvent at 702 °C. The energetics of surface hydration has been measured using a Calvet microcalorimeter coupled with a gas dosing system. The surface enthalpies of hydrated surfaces for anatase TiO2 nanoparticles, nanowires and sea-urchin-like assemblies are 0.51 ± 0.05, 1.07 ± 0.28, and 1.29 ± 0.16 J m-2, respectively, whereas those of anhydrous surfaces are 0.74 ± 0.04, 1.24 ± 0.28, and 1.41 ± 0.16 J m-2, respectively. The trend in TiO2, which shows higher surface enthalpies for more complex nanostructures, is consistent with that reported in ZnO. The shape-dependent surface enthalpy at the nanoscale level is discussed in terms of exposed surface structures. The enthalpies of hydration appear to be similar for all morphologies.
UR - http://www.scopus.com/inward/record.url?scp=77957769345&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77957769345&partnerID=8YFLogxK
U2 - 10.1039/c0jm02192j
DO - 10.1039/c0jm02192j
M3 - Article
AN - SCOPUS:77957769345
SN - 0959-9428
VL - 20
SP - 8639
EP - 8645
JO - Journal of Materials Chemistry
JF - Journal of Materials Chemistry
IS - 39
ER -