Investigation of the photocatalytic and biological applications of iron oxide–indium oxide nanocomposite

Iron oxide nanoparticles (Fe3O4 NPs) and iron–indium oxide nanocomposite (Fe3O4-In2O3 NC) were prepared through chemical reduction approach and utilized for the photodegradation of methylene blue (MB) dye in aqueous solution. The as-synthesized materials were characterized by scanning electron microscopy (SEM), thermo-gravimetric analysis (TGA), energy-dispersive X-rays (EDX) as well as Fourier transform infrared (FT-IR). SEM studies showed that NPs were present both in discrete and in agglomerated form having round shape and size below 100 nm. FTIR analysis also confirms synthesis of oxide nanoparticles. Fe3O4 NPs and Fe3O4-In2O3 NC are employed as photocatalysts for photodegradation of MB, and about 88 ± 1 and 97 ± 1% dye was photodegraded in 6 h under UV light, respectively. Recovered Fe3O4 and Fe3O4-In2O3 nanoparticles significantly photodegraded MB dye. The effect of important parameters such as effect of pH, H2O2, catalyst dosage and initial dye concentration on dye degradation was studied. Degradation study was also carried out under visible light; obtained result indicated that photodegradation ability of Fe3O4-In2O3 NC is less in visible light (60 ± 1% dye degradation in 6 h) than the degradation under UV light. Promising bioactivities were demonstrated by Fe3O4-In2O3 NC against two pathogenic bacteria Proteus mirabilis and Acinetobacter baumannii. Fe3O4-In2O3 NC exhibited excellent antioxidant activity (87 ± 1%) almost comparable to the standard ascorbic acid (90 ± 1%).