Synthesis and characterization of SiO2 doped Fe2O3 nanoparticles: Photocatalytic and antimicrobial activity evaluation

Abstract Silica doped iron oxide (SiO 2 doped Fe 2 O 3 ) nanoparticles (NPs) were successfully synthesized by co-precipitation method at 70 °C using different solvents (acetonitrile, n -hexane and isoamyl alcohol). The synthesized NPs were characterized by FT-IR, X-Ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), thermal gravimetric analysis-differential scanning calorimetry (TGA-DSC) and dynamic light scattering (DLS) techniques. The size of SiO 2 doped Fe 2 O 3 NPs was in the range of 5.89 nm–19.89 nm and ellipsoidal morphology with tendency of aggregate formation due to dipole-dipole interactions. The solvents showed variable effect on physico-chemical properties of the NPs. As-synthesized NPs were also evaluated for the antimicrobial activity against set of bacterial and fungal strains i.e., Candida parapsilosis, Aspergilus niger, Bacillus subtilis and Escherichia coli . It was observed that solvents also affected the NPs antimicrobial activity. The SiO 2 doped Fe 2 O 3 NPs prepared in acetonitrile showed highest antibacterial as well as antifungal activity. The MIC values were recorded to be 0.31 mg/L and 0.21 mg/L (acetonitrile) and 0.24 mg/L and 0.18 mg/L (isoamyl alcohol) for C. parapsilosis and A. niger, respectively. NPs prepared in n -hexane showed the MIC value of 0.09 mg/L. The photocaalytic activity (PCA) was evaluated by degrading Rhodamine B (RhB) dye. The RhB degradation was 83% for Fe 2 O 3 NPs, which was enhanced considerably in case of doping, solvents also showed variable effect on the PCA for RhB dye degradation. Results revealed that the SiO 2 doped Fe 2 O 3 NPs are efficient antimicrobial agent as well as highly active photocatalysts and could possibly be used for the degradation of dyes in textile wastewater.