Biogenic synthesis of Fe3O4/NiO nanocomposites using Ocimum basilicum leaves for enhanced degradation of organic dyes and hydrogen evolution

Abstract

This research aims to explore the utilization of Ocimum basilicum leaf extract as a green and sustainable method for the synthesis of Fe₃O₄/NiO nanocomposites (Fe₃O₄/NiO NC) with potential applications in photocatalytic hydrogen evolution and organic dye degradation. The synthesized Fe₃O₄/NiO NC exhibited a unique bandgap energy of 2 eV, making it an effective visible-light photocatalyst. X-ray diffraction and scanning electron microscopy confirmed the successful formation of the cubic crystal structure with an average crystallite size of 25.7 nm. Fourier transform infrared spectroscopy analysis revealed the presence of hydroxyl groups on the NC surface, which contributed to its photocatalytic properties. Under sunlight exposure, the Fe₃O₄/NiO NC demonstrated remarkable photocatalytic degradation efficiency of 99.3% for toluidine blue, 99.0% for 4-bromophenol, and 95.0% for methyl blue within 140 min. The photocatalyst also exhibited excellent reusability with only a slight decrease in efficiency after five cycles. Additionally, the Fe₃O₄/NiO NC displayed high photocatalytic activity in hydrogen evolution, generating 933.9 µmol/g of H₂ over 8 h at a concentration of 0.7 g/L. This green synthesis approach, utilizing Ocimum basilicum extract, provides a cost-effective and eco-friendly method to produce Fe₃O₄/NiO NC with enhanced photocatalytic properties, holding great promise for sustainable energy and water purification applications. The study contributes to the understanding of novel nanocomposites and their potential for addressing urgent environmental challenges, underscoring their scientific value in green chemistry and renewable energy research.