Shape-dependent Surface Energetics of Nanocrystalline TiO2

Journal Article · Thu Oct 21 04:00:00 EDT 2010 · Journal of Materials Chemistry

DOI:https://doi.org/10.1039/c0jm02192j· OSTI ID:1000451

Park, T J; Wong, S; Levchenko, A A; Zhou, H; Navrotsky, A

We report the direct determination of surface enthalpies for nanophase TiO{sub 2} anatase with different morphologies derived from drop solution calorimetry in a molten sodium molybdate (3Na{sub 2}Ol{center_dot}4MoO{sub 3}) 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 TiO{sub 2} nanoparticles, nanowires and sea-urchin-like assemblies are 0.51 {+-} 0.05, 1.07 {+-} 0.28, and 1.29 {+-} 0.16 J m{sup -2}, respectively, whereas those of anhydrous surfaces are 0.74 {+-} 0.04, 1.24 {+-} 0.28, and 1.41 {+-} 0.16 J m{sup -2}, respectively. The trend in TiO{sub 2}, 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.

• Research Organization: BROOKHAVEN NATIONAL LABORATORY (BNL)
• Sponsoring Organization: DOE - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1000451
• Report Number(s): BNL--94399-2010-JA; KC0202020
• Journal Information: Journal of Materials Chemistry, Journal Name: Journal of Materials Chemistry Journal Issue: 39 Vol. 20; ISSN JMACEP; ISSN 0959-9428; ISSN 1364-5501
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
CALORIMETRY
ENTHALPY
HYDRATION
MOLYBDATES
NANOSTRUCTURES
SODIUM
SOLVENTS