Premium
Relationship between morphology and structure of shape‐controlled CeO 2 nanocrystals synthesized by microwave‐assisted hydrothermal method
Author(s) -
Bezkrovnyi O. S.,
Lisiecki R.,
Kepinski L.
Publication year - 2016
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.201600053
Subject(s) - hydrothermal circulation , nanocrystal , morphology (biology) , materials science , microwave , chemical engineering , hydrothermal synthesis , nanotechnology , computer science , telecommunications , geology , engineering , paleontology
The influence of synthesis conditions on morphology and structure of CeO 2 nanocrystals prepared by microwave‐assisted hydrothermal method were studied by XRD, TEM, Raman spectroscopy and photoluminescence measurements. Decisive effect of the OH ‐ /Ce 3+ molar ratio in the reaction mixture on the size and shape of CeO 2 nanocrystals was established and explained. Rise of the concentration of OH ‐ groups at the surface of growing CeO 2 nanocrystals promotes shape transformation from irregular (spheroidal) to cube and enables oriented attachment mode of particle growth. I was found that the unit cell parameter and intensity of Ce 3+ defect related band in the luminescence and Raman spectra in ceria nanoparticles increase as follows: irregular shape nanocrystals < large cube < small primary cube shape particles. The reason is growing contribution of total subsurface volume under {100} faces, exposed by ceria nanocubes, where enhanced concentration of Ce 3+ and oxygen vacancies occur.