Development of Nb-Doped BiFeO₃ via Hydrothermal Method for Photocatalytic Degradation of Rhodamine B (RhB) Dye

Bismuth ferrite, or BiFeO3, is a highly promising material within the realm of multiferroics due to its stable structures, small band gap and cost-effectiveness. The present study employed a facile and eco-friendly approach to synthesize high-purity niobium-doped and -undoped bismuth ferrite (BiFeO3) nanostructure with hydrothermal method. The findings of the study indicate that the produced Nb-doped BFO exhibited nanoflake morphology as verified by SEM analysis. The observed trend in the photocatalytic efficiency of the material was found to be closely associated with the change in the band gap energy, which decreased from 2.36 eV to 2.03 eV with niobium dopant. The present study assessed the photocatalytic performance of both doped and pristine BiFeO3 for the decomposition of rhodamine B (RhB) under visible source of light radiation. The photocatalytic behavior of niobium-doped BiFeO3 for the mineralization of RhB was observed with increase upon contact time to visible light. The observed phenomenon can be ascribed to the effective dissociation of photogenerated electron (e(-)) and hole (h(+)) pairs, as well as the significant absorption of visible light, as opposed to the pristine BiFeO3. The scavenger analysis revealed that hydroxyl species, radical and holes species play a significant role in the photocatalytic mineralization of RhB. Later research revealed that the kinetics of the photocatalytic RhB decomposition followed the Langmuir-Hinshelwood model.