Catalytic Effect of GdVO4:Eu3+Nanocrystals Over H2O2 Decomposition Reaction

Hydrogen peroxide (H
2
O
2
) is a member of the reactive oxygen species (ROS) family and participates in numerous redox metabolism reactions and cellular processes. H
2
O
2
is regarded as a pivotal component in the homeostatic metabolism of cells, acting as a mediator in various physiological processes including cell differentiation, proliferation, survival, and immune response. Nevertheless, the Fenton reaction between H
2
O
2
and Fe
²⁺
ions serves as the primary trigger for biomolecule oxidation reactions, resulting in the formation of highly reactive hydroxyl radicals (.OH). Hence, there is a great interest in preventive antioxidants that can react with H
2
O
2
without generating free radicals, such as .OH. In the present work, we analyze the mechanism of H
2
O
2
decomposition by GdVO
4
:Eu
³⁺
nanoparticles (NPs) in aqueous solutions using optical spectroscopy technique. The synthesized NPs were characterized by TEM, HR-TEM, XRD, and XPS methods. The possibility of Fenton- and catalase-like reactions of H
2
O
2
decomposition in aqueous solutions containing GdVO
4
:Eu
³⁺
NPs has been analyzed. Obtained results indicate that the Fenton-like reaction with the participation of V
⁴
+/V3+ ions detected in a high amount at the surface of GdVO
4
:Eu
³⁺
NPs, and .OH generation is not a likely scenario in the system under study. At the same time, it has been revealed that H
2
O
2
likely acts as a reductant donating electron to V5+ ions in GdVO
4
:Eu
³⁺
NPs that was confirmed by increasing the amount of V
⁴
+ and V3+ ions and decreasing V5+ ions content and the transformation of the GdVO
4
:Eu
³⁺
absorption spectrum, as well. Thus, GdVO
4
:Eu
³⁺
NCs could be prospective as an effective preventive antioxidant for H
2
O
2
decomposition by catalase-like reaction.