About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
|
Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
|
Presentation Title |
Surface Thermochemistry of TiO2 Doped with Alkaline Earth Metal Ions and Its Relationship with Nanostructure |
Author(s) |
Andre L. Da Silva, Bruno Ramos, Jefferson Bettini, Ricardo Castro, Douglas Gouvêa |
On-Site Speaker (Planned) |
Bruno Ramos |
Abstract Scope |
This work investigates the relationship between the surface thermochemistry of TiO2 doped with alkaline earth metal ions and the micro and nano-structural features. The polymeric precursor method enabled the synthesis of TiO2 nanoparticles containing Mg2+, Ca2+, Sr2+, or Ba2+. Dopants' spontaneous segregation to the nanoparticles' interfaces led to an incremental surface energy reduction directly measured by microcalorimetry of adsorption. The surface excess was directly measured using an innovative lixiviation method and then, confirmed by EELS and EDS combined with STEM. The phenomenon was a direct function of ionic radius and led to improved thermal stability against coarsening and, consequently, stabilizing the anatase polymorph and increasing the specific surface area. |