Microstructure of Antioxidants Based on Orthovanadate Nanocrystals: XPS Study

In the present study three types of oxide
$\text{LnVO}_{4}:\text{Eu}^{3+}$
(Ln = Gd, Y, La) nanocrystals with variable valence ions and different sizes and shapes were investigated. We have experimentally demonstrated that a decrease in nanocrystals size leads to an increase of the reduced vanadium ion content. Synthesized nanocrystals were characterized by HR-TEM, XRD and XPS methods. XPS method allowed us to concluded that for small
$\text{GdYVO}_{4}:\text{Eu}^{3+}$
nanocrystals, the number of reduced vanadium ions is more than 60% which makes these nanocrystals the most promising for the neutralization of reactive oxygen species.