Boosting stability and photocatalytic efficiency: Gd-doped bismuth ferrite thin films for effective water contaminant removal

Abstract

Recent developments in photocatalysts have focused on enhancing photocatalytic activities to improve the degradation of toxic molecules present in sewage waters. While significant improvements in photocatalytic efficiency have been achieved, stability remains a critical challenge. Ensuring that photocatalysts maintain their performance over time is essential for practical applications in water treatment. Consequently, this study concentrates on Gd-doped BiFeO<inf>3</inf> (Gd:BFO) photocatalysts synthesized using the spray pyrolysis technique. The performance of Gd:BFO thin film photocatalysts was evaluated for the degradation of methyl orange (MO) dye under solar irradiation. The fabricated thin films were characterized through X-ray diffraction, ultraviolet-visible spectroscopy, and scanning electron microscopy. Results showed that Gd doping in BFO decreased the water contact angle compared to undoped BFO, indicating improved surface wettability. Additionally, Gd doping reduces electron-hole recombination, leading to enhanced photocatalytic activity. Remarkably, the Gd:BFO photocatalyst achieved a maximum degradation efficiency of 98 % for MO within 60 min of solar irradiation, while BFO reached only 82 % under the same conditions. Moreover, Gd doping enhanced the stability of BFO photocatalyst during dye degradation, allowing for consistent photocatalytic performance over nearly 8 cycles. © © 2025. Published by Elsevier B.V.