TiO2 Surface Engineering to Improve Nanostability: The Role of Interface Segregation

Autor: Ricardo H. R. Castro, Alexandra Navrotsky, André Luis Porto da Silva, Douglas Gouvêa, Dereck N.F. Muche, Lorena Batista Caliman, Jefferson Bettini
Rok vydání: 2019
Předmět:
Zdroj: The Journal of Physical Chemistry C. 123:4949-4960
ISSN: 1932-7455
1932-7447
DOI: 10.1021/acs.jpcc.8b12160
Popis: Nanoparticle stability against coarsening is one of the keys to allow better exploitation of the properties of nanoscale materials. The intrinsically high interfacial energies of nanoparticles constitute the driving force for coarsening, and therefore can serve as targets to design materials with improved thermal stability. In this study, we discuss the surface engineering of TiO2 nanocatalysts for artificial photosynthesis by exploiting the spontaneous segregation of Ba2+ ions to the interfaces of TiO2 nanocrystals. Ba2+ is a strong candidate for photoelectrocatalytic reduction of CO2 and its effects on interfacial energies lead to a remarkable increase in thermal stability. By using a systematic lixiviation method, we quantified the Ba2+ content located at both the surface and at grain boundary interfaces and combined with direct calorimetric measurements of surface energies and microstructural studies to demonstrate that Ba2+ excess quantities directly impact coarsening of TiO2 nanocatalysts by creatin...
Databáze: OpenAIRE