LAUSR

Abstract Catalytic properties of Bi2S3 nanostructures, Fe3O4 nanoparticles and novel Bi2S3@Fe3O4 magnetic nanocomposites were investigated. Flower-like Bi2S3 nanostructures were produced using hydrothermal synthesis. Bi2S3 nanostructures were doped with Fe3O4 nanoparticles where Bi2S3@Fe3O4 novel magnetic nanocomposites was obtained. Structural characterization of the nanoflowers were performed using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Microscopic characterization of the nanoflowers was performed using electron microscopy where scanning electron microscope (SEM) and transmission electron microscope (TEM) were used in the characterization which confirms the flower like structures. Vibrating sample magnetometry (VSM) confirmed the magnetic properties of the ferromagnetic characteristics of the magnetic nanocomposites. Optic properties of the nanoparticles were assessed using Ultraviolet - visible (UV–vis) spectroscopy. Band gap energies of the Bi2S3, Fe3O4 and Bi2S3@Fe3O4 were found to be 1.80 eV, 2.0 eV and 2.72 eV, respectively. Catalytic properties of the Bi2S3@Fe3O4 nanoparticles were confirmed using UV spectroscopy where reduction of p-nitrophenol to p-aminophenol was assessed in the presence of NaBH4. It was concluded that Bi2S3 nanostructures and Bi2S3@Fe3O4 nanocomposites showed better catalytic performance than that of Fe3O4 nanoparticles. Such a case was attributed to increased surface area - volume ratio. Results indicate that nanocomposites have the potential to be used in the wastewater treatment.