Green Synthesis of Nanoparticles: An Emerging Phytotechnology

Abstract

The metallic particles whose size ranges between 1 and 100 nm in any one of the dimensions are termed as nanoparticles (NPs). Nanoparticles pose a great interest to chemists, physicists, biologists, and engineers for the development of new generation nanodevices, electronics, catalysis, chemistry, energy, and medicine. “Green synthesis” refers to the use of green material (i.e., plants) for the synthesis of any material. Nanoparticles can be synthesized by various ways, viz., laser ablation, gamma irradiation, electron irradiation, chemical reduction, photochemical methods, and microwave processing, which however produce hazardous chemicals as by-product. Green synthesis of NPs is presently becoming popular due to its eco-friendly and cost-effective approach with no use of any toxic chemicals. At the same time, synthesis of NPs through biological methods is not as easy and lots of open challenges are there. Green synthesis of NPs involves the use of water in closed reactors, which is a nontoxic solvent, and applies green techniques like ultrasound and microwave. The reagents used for the synthesis of NPs also include natural compounds such as sugars, vitamins, biodegradable compounds, and microbes. Among these reagents, plant-based materials are the most suitable candidates for large-scale synthesis of NPs. Several plants and their compounds are being used for green synthesis of NPs. This chapter focuses on the range of plants being used for various NP biosynthesis and also gives a view of various applications of NPs in diverse fields.