Bismuth ferrite thin film as an efficient electrode for photocatalytic degradation of Methylene blue dye

The Bismuth Ferrite [BiFeO₃-(BFO)] thin film, as a visible-light-driven photocatalytic electrode, is synthesized using the simple spray pyrolysis method. BFO thin films prepared at different precursor concentrations of 4 mM, 6 mM, 8 mM and 10 mM are utilized to degrade organic dyes such as Methylene blue (MB), Congo red (CR), Ponceau-S (PS) at different light irradiation times. Single-phase and polycrystalline nature with rhombohedral crystal structure are observed for all the BFO samples. BFO is seen to have hydrophilic nature for the films deposited at 6, 8 and 10 mM, which transits to the hydrophobic nature for films deposited at lower concentration of 4 mM. The optical study reveals light absorption in the visible-region of the electromagnetic spectrum for all the BFO samples indicating the use of BFO as photoelectrode in visible-region. BFO samples showed photocatalytic degradation activity with its reusability for the studied dyes i.e., MB, CR, and PS. Significantly, higher efficiency of MB dye degradation was noted. Moreover, after MB dye degradation, the physical properties of BFO film are again studied, which indicated good stability for BFO sample prepared at 10 mM precursor concentration. (paper)