Degradation of malachite green dye by capping polyvinylpyrrolidone and Azadirachta indica in hematite phase of Ni doped Fe2O3 nanoparticles via co-precipitation method

Abstract

In the present research, a chemical co-precipitation approach has been used to approach the synthesis, characterization, and photocatalytic applicability of Ni-doped α-Fe2O3 (hematite) nanoparticles. Biosynthesized iron oxide nanoparticles (IONPs) were successfully synthesized using a non-toxic leaf extract of the Azadirachta indica (AI) plant (neem) as a reducing and stabilizing agent. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, FT-IR spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, and vibrating sample magnetometer (VSM) have all been used to examine the synthesized materials. All of the produced NPs contain only the nanocrystalline hematite phase, according to XRD measurements. The morphology studies of the Ni-doping hematite nanoparticles, as demonstrated by TEM and SEM. The phase purity and phonon modes of the prepared nanoparticles are confirmed by Raman spectroscopy. The UV-Vis absorption tests show also that value of the band gap increases together with the reduction in particle size, going from 2.26 eV for chemical α-Fe2O3 to 2.5 eV for green Ni-doped α-Fe2O3 nanoparticles. Additionally, it was clear from the magnetic characteristics that all of the samples behaved ferromagnetically at ambient temperatures. On the other side, malachite green (MG) dye was used as a surrogate industrial wastewater dye in order to study the photocatalytic efficiency of Ni-doped α-Fe2O3 particles. The pure/green Ni-doped α-Fe2O3 NPs showed that after 70 minutes of exposure, 92% of the MG had become discolored.