Microwave assisted green synthesis of γ-Fe2O3 nanoparticles and their application for photodegradation of ternary dye mixture

This work presents green, microwave mediated, rapid, and economical synthesis of γ-Fe₂O₃ nanoparticles (NPs) using Mangifera indica leaves extract. Structural and morphological characterizations infer about the formation of γ-Fe₂O₃ NPs having spherical shape with ~13 nm particle size. Magnetic M-H loop measurement reveals that γ-Fe₂O₃ NPs exhibit superparamagnetic behavior. γ-Fe₂O₃ NPs are tested for photocatalytic activity under dark, UV, and visible condition against the individual Rhodamine B (RhB), Malachite green (MG), and Methyl orange (MO) dyes and their ternary mixture. About 91.49% degradation efficiency is obtained for RhB using 0.2 g/dm³ γ-Fe₂O₃ NPs in 60 min. Degradation efficiency noted against RhB, MG, and MO in ternary mixture is 75.98%, 79.9%, and 71.8%, respectively, under UV irradiation in 60 min. Recycling study of γ-Fe₂O₃ NPs suggests that NPs can be used even after three cycles with good degradation efficiency. Therefore, the synthesized γ-Fe₂O₃ NPs may find applications as photocatalytic agents for waste water and crude dye mixture treatment.