Dual oxidation state induced oxygen vacancies in Pr substituted BiFeO3 compounds: An effective material activation strategy to enhance the magnetic and visible light-driven photocatalytic properties. (May 2018) - Bharathkumar, S.
Graphical abstract: Highlights: BiFeO3 with tunable oxygen vacancy is achieved through Pr substitution. Dual oxidation of Pr ions is found to be the origin of oxygen vacancies in BiFeO3 . Mechanism of the observed photocatalytic activity could be due to the oxygen vacancy. Abstract: Bi1- x P x FeO3 (BP x FO) nanoparticulates with tunable oxygen vacancy have been synthesized via sol-gel process. Substitution induced oxygen vacancy defects in BP x FO compositions were evidenced from their X-ray photoelectron spectra, where the mechanism behind the formation of oxygen vacancy was essentially found to be the dual oxidation states of Pr (+3/+4) ions. The origin of the observed enhanced magnetic properties in BP x FO nanoparticulates is attributed to be the oxygen vacancy mediated alterations in FeOFe bond angle and the alignment of Pr-3d magnetic moments with Fe-3d magnetic moments, which is resulted the ferromagnetic exchange interactions in the BP x FO system. The observed enhanced photocatalytic activity of BP x FO compositions is attributed to the formation of defective states in the valence band due to the oxygen vacancies that favored the dispersion of band edge position with required photocatalytic redox potential as well as the acceleration of the charge separation process in these defective BP x FO systems.