A novel synthesis and characterization of polyhedral shaped amorphous iron oxide nanoparticles from incense sticks ash waste

Abstract

This research study has investigated the potential applicability of incense sticks ash (ISA), a waste material, in synthesizing highly pure iron oxide nanoparticles (IONPs). Synthesis of IONPs from ISA involved five major steps: burning of incense sticks to collect ISA, recovery of ferrous fractions from wet slurry by magnetic separation method, acidic treatment of ferrous fractions under sonication, formation of IONPs by co-precipitation method by using NaOH, calcination of the obtained powder in a muffle furnace. The IONPs synthesized from ISA extracted ferrous particles have two different types of particles, small circular disk shaped of size 60–200 nm in diameter, while larger rectangular particles whose diameter was 150–600 nm by length. The formation of large particles is due to the agglomeration of several small IONPs. The synthesized nanoparticles were amorphous and polyhedral in shape. These IONPs were characterized by Particle size analyzer (PSA), X-ray powder diffraction (XRD), Transmission Electron Microscopy (TEM), Field emission-scanning electron microscopy (FESEM), Electron diffraction spectroscopy (EDS), Atomic Force Microscopy (AFM) and Fourier-transform infrared spectroscopy (FTIR). The FTIR spectra revealed the characteristic bands at 452 and 565 cm−1 which is attributed to Fe–O bonds of IONPs, while the XRD diffractogram supported the amorphous nature of IONPs by showing a broad peak at 2θ, 36.090. The average particle size and polydispersity index (PDI) revealed by PSA was 734.9 nm and 0.357respectively. Since the size given by PSA is in hydrodynamic radius so there is large average size of the particles. The polyhedral shape was confirmed by the microscopic techniques while the presence of Fe and O peaks only by EDS confirmed the purity of the synthesized IONPs. The result obtained in the mentioned method proves that ISA waste can be utilized to synthesize highly pure IONPs by an economical and eco-friendly approach. The current method also focuses on the reduction of solid waste and water pollution arising due to the ISA disposal in water bodies. In, future, ISA may be used as substitute source material for all the ferrous and ferrous based industries (steel). Moreover, based on the purity, in subsequent time it could be used in magnetic resonance imaging (MRI), drug delivery, and as an adsorbents for the environmental clean-up.