Surface enthalpies of nanophase ZnO with different morphologies

Peng Zhang, Fen Xu, Alexandra Navrotsky, Jong Soo Lee, Sangtae Kim, Jun Liu

Research output: Contribution to journalArticlepeer-review

65 Scopus citations

Abstract

A direct calorimetric measurement of the dependence of the surface enthalpy of nanophase ZnO on morphology is reported. Nanoparticles, nanoporous composites, nanorods, and nanotetrapods were prepared with various sizes, and their surface enthalpies were derived from their drop solution enthalpies in molten sodium molybdate. Water adsorption calorimetry for nanoparticles and nanorods was carried out to characterize the stabilization effect of surface hydration. The surface enthalpies of hydrated surfaces for nanoparticles, nanoporous composites, nanorods, and nanotetrapods are 1.31 ±0.07, 1.42 ±0.21, 5.19 ± 0.56, and 5.77 ±2.50 J/m 2, respectively, whereas those of the anhydrous surfaces are 2.55 ±0.23, 2.74 ±0.16, 6.67 ±0.56, and 7.28 ±2.50 J/m 2, respectively. The surface enthalpies of nanoparticles are the same as those of nanoporous composites and are much lower than those of nanorods and nanotetrapods, which also are close to each other. The dependence of surface enthalpy on morphology is discussed in terms of exposed surface structures. This is the first time that calorimetry on nanocrystalline powders has been able to detect differences in surface energetics of materials having different morphologies.

Original languageEnglish (US)
Pages (from-to)5687-5693
Number of pages7
JournalChemistry of Materials
Volume19
Issue number23
DOIs
StatePublished - Nov 13 2007
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'Surface enthalpies of nanophase ZnO with different morphologies'. Together they form a unique fingerprint.

Cite this