Simple One-Step Leaf Extract-Assisted Preparation of α-Fe2O3 Nanoparticles, Physicochemical Properties, and Its Sunlight-Driven Photocatalytic Activity on Methylene Blue Dye Degradation

Abstract

Hematite nanoparticles have been prepared from Moringa oleifera leaf extracts. Phytochemicals are derived from plant extracts which act as a stabilizing and capping agent as well as a surfactant. This green route protocol is attractive owing to its speed, reliability, and ecofriendly and cost-effective qualities. The synthesized iron oxide nanoparticles were subjected to three different calcination temperatures (500, 600, and 700°C). The crystallinity nature and phase purity have been confirmed by powder X-ray diffraction (PXRD). Optical properties have been studied by UV-visible (UV-vis) and diffuse reflectance spectroscopy (DRS). A very narrow bandgap was observed, and absorbance was observed at the visible region. Photoluminescence spectra have exhibited a multicolor emission band from the near UV to visible region due to defect centers (F centers). EDX (energy dispersive X-ray spectrum) has given information on the stoichiometric ratio of Fe and O. The functional groups which are responsible for nanoparticle formation have been identified by Fourier transformed infrared spectroscopy (FTIR), surface morphology transformation has been illustrated by scanning electron microscopy (SEM) studies, and VSM measurements have exhibited a hysteresis curve that shows the weak and strong ferromagnetic behavior in nature at RT. TEM micrographs have confirmed that particles are in the nanorange, matching the results from the XRD report. The SAED pattern gives information on the polycrystalline nature of hematite nanoparticles. TG-DSC characterization revealed phase transition, decomposition, and weight loss information. Frequency-dependent electrical properties were studied. Here, we report what the present studies have revealed: that hematite nanopowder prepared from the green route is environmentally friendly, takes a short time to prepare, is an economical and promising candidate material for electromagnetic devices and ferromagnet manufacturing, and is a photocatalyst in water treatment applications without adding additives (H2O2).