Green Synthesized Nanomaterials: Principles, Progress, and Perspectives
Navid Rabiee
Abstract
This chapter provides a comprehensive introduction to the burgeoning field of green synthesized nanomaterials, a sustainable alternative to conventional nanomaterial fabrication routes. It begins by establishing the environmental and economic imperatives driving the shift towards green nanotechnology, rooted in the twelve principles of green chemistry. The chapter meticulously details the diverse array of biological entities, including plants, bacteria, fungi, algae, yeast, and viruses, along with isolated biomolecules (proteins, polysaccharides, vitamins) that serve as eco-friendly reducing and capping agents. The fundamental mechanisms underlying green nanoparticle formation, encompassing bioreduction, nucleation, growth, and biomolecular stabilization, are thoroughly discussed. A significant portion is dedicated to exploring the synthesis of a wide variety of nanomaterials via these green pathways, including metallic (Ag, Au, Cu, Pt, Pd), metal oxide (ZnO, Fe-oxides, TiO 2 ), and chalcogenide (Se, QDs) nanoparticles, highlighting their characteristic properties. The inherent advantages of green synthesis, such as environmental benignity, cost-effectiveness, energy efficiency, and often enhanced biocompatibility due to natural capping agents, are critically evaluated against current limitations like reproducibility, mechanistic complexity, polydispersity, and scale-up challenges. Furthermore, the chapter surveys the current and emerging applications of these sustainably produced nanomaterials across diverse sectors, with a particular focus on biomedical applications (antimicrobial agents, drug delivery, cancer therapy, bioimaging, biosensors, tissue engineering), environmental remediation (photocatalysis, heavy metal adsorption, water disinfection), catalysis, and the agriculture/food industry. It concludes by outlining key future perspectives and research directions essential for overcoming existing hurdles and realizing the full transformative potential of green synthesized nanomaterials in fostering a truly sustainable and responsible nanotechnology landscape.