Green Synthesis of Metal Oxide Nanoparticles Using Plant Extracts: Applications in Catalysis and Biomedicine

ABSTRACT The green synthesis of metal oxide nanoparticles (MONPs) using plant‐based resources has gained significant traction as an environmentally benign, cost‐effective, and scalable alternative to traditional chemical and physical methods. This review comprehensively explores the plant‐mediated synthesis routes for a variety of MONPs, including CuO, CaO, FeO, PbO, ZnO, and TiO 2 , emphasizing the role of phytochemicals as natural reducing, capping, and stabilizing agents. We discuss the physicochemical properties conferred by the green synthesis approach, such as tailored morphology, particle size control, surface functionality, and biocompatibility. Comparative analyses are provided to highlight morphological variations and activity profiles of MONPs derived from different botanical sources. Furthermore, we critically evaluate the emerging applications of these phytogenic nanomaterials in photocatalysis, antimicrobial activity, and biosensing. Special attention is given to the mechanistic insights that govern the functionality of these nanoparticles and their interface with pollutants and pathogens. The review concludes by outlining key research gaps, challenges in large‐scale reproducibility, and future opportunities for integrating green‐synthesized MONPs in circular nanotechnology frameworks. This work aligns with the growing demand for sustainable materials in coordination chemistry and offers valuable insights into nature‐inspired nanomaterial development.