Green and energy-efficient methods for the production of metallic nanoparticles

Abstract

In the last decade, researchers paid great attention to the concept of "Green Chemistry", which aims at development of efficientmethods for the synthesis of nanoparticles (NPs) in terms of the least possible impact on human life and environment. Generally,several reagents including precursors, reducing agents, stabilizing agents and solvents are used for the production of NPs and insome cases, energy is needed to reach the optimum temperature for reduction. Therefore, to develop a green approach, researchershad the opportunity to investigate eco-friendly reagents and new energy transfer techniques. In order to substitute the harmfulreagents with green ones, researchers worked on different types of saccharides, polyols, carboxylic acids, polyoxometalates andextracts of various plants that can play the role of reducers, stabilizers or solvents. Also, there are some reports on using ultraviolet(UV), gamma and microwave irradiation that are capable of reducing and provide uniform heating. According to the literature, it ispossible to use green reagents and novel energy transfer techniques for production of NPs. However, these new synthesis routesshould be optimized in terms of performance, cost, product quality (shape and size distribution) and scale-up capability. This paperpresents a review on most of the employed green reagents and new energy transfer techniques for the production of metallic NPs.