A review on multifunctional applications of MgO nanostructures: from material science to environmental and agricultural innovations

Abstract

Green synthesis of magnesium oxide nanoparticles (MgO NPs) using plant extracts and bio-waste materials represents a sustainable alternative to conventional synthesis methods. MgO, characterized by its crystalline lattice of Mg²⁺ and O²⁻ ions, exhibits hygroscopic properties and is a white, solid mineral with diverse technological applications. These nanoparticles demonstrate versatile applications across multiple disciplines, including agriculture, drug delivery, environmental remediation, antimicrobial treatments, and supercapacitor technologies. Previous studies describe diverse synthesis methodologies including sol–gel routes, flame synthesis, and hydrothermal methods, whereas this review focuses primarily on green synthesis approaches. The green synthesis methodology employs plant extracts that serve dual functions as both reducing agents and capping agents in the formation and stabilization of metal oxide nanoparticles. Biosynthesized MgO NPs exhibit distinctive properties, including controlled morphology, high surface area, tunable particle size distribution, and enhanced stabilization. These characteristics position MgO NPs as promising candidates for addressing contemporary environmental challenges and advancing energy storage technologies. This review critically analyzes recent developments in biosynthesized MgO NPs, highlighting the advantages of green synthesis over conventional methods and identifying key research gaps and future directions in this rapidly evolving field.