Green synthesis of template-free NiFe2O4 nanoparticles: A promising sustainable catalyst for efficient benzaldehyde and phenolic motifs development

This study introduces cost-effective and eco-friendly approach utilizing Camellia sinensis var. Assamica leaves for biogenic synthesis of NiFe₂O₄ magnetic nanoparticles. The synthesized nanoparticles underwent comprehensive characterization employing SEM-EDX, VSM, PXRD, XPS and TEM analyses to provide detailed insights into their properties. TEM investigations unveiled the formation of spherical NiFe₂O₄ magnetic nanoparticles, while VSM analysis revealed their ferromagnetic behavior. They demonstrate outstanding catalytic performance in the ipso-hydroxylation of arylboronic acids within very short amount of time without using any solvent/ base at room temperature. Remarkably, under base-free and mild reaction conditions, a diverse range of benzyl alcohols exhibited conversion to their corresponding aldehydes, showcasing the versatility and efficacy of as-synthesized nanoparticles. These nanoparticles could be readily separated using magnet and maintain their catalytic activity consistently for upto fifth run in both reactions, presenting significant economic advantages for potential industrial applications.