Abstract
When kinetic conditions dominate and dictate the growth in a nanoparticle synthesis, properties of the synthesis environment can have considerable effects on the properties of the products. Such effects were studied here, where the solution environment was changed via the addition of KF to the hydrothermal syntheses of KTa1-xNbxO3 and KTaO3. One result demonstrated the straightforward cause-and-effect relationship between the solution and reaction kinetics: KF directly increased the solution stability of the Ta species and therefore decreased its reaction rate, resulting in a change in composition heterogeneity of Ta and Nb in the KTa1-xNbxO3 particles. However, not all effects are so simple; changing the chemical potential of the solution with KF can also promote the formation of particles with anisotropic defect enhanced kinetic Wulff shapes instead of cuboidal shapes. The increased F chemical potential in the solution enabled the formation of planar defects in the bulk, which accelerated growth in-plane to form particles characterized by flat rectangular flake geometries. Thermodynamic modeling with density functional theory calculations confirmed that sufficient KF concentrations can drive the formation of a defect phase Kn+1TanO3nF.
Original language | English (US) |
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Pages (from-to) | 26012-26017 |
Number of pages | 6 |
Journal | Journal of Physical Chemistry C |
Volume | 124 |
Issue number | 47 |
DOIs | |
State | Published - Nov 25 2020 |
Funding
This work was supported by the National Science Foundation (NSF) under grant no. DMR-1507101. Use of the Center for Nanoscale Materials, an Office of Science User Facility, was supported by the United States Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02-06CH11357. We thank K. R. Poeppelmeier for use of his hydrothermal synthesis laboratory equipment, and C. A. Mizzi for his assistance with X-ray photoelectron spectroscopy.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- General Energy
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films