*4.2.1 Microwave oven*

The microwave oven that could be used for synthesis of nanoparticles is one of the popular techniques. The microwave oven is a method for the processing of nanoparticles using different intensities of microwave radiation. Here the reactant, which may be a capping agent, is mixed with metallic salts and the mixture is placed in a microwave oven. Microwave treatment is administered to the reaction mixture in a short burst of 20 s for 5 min, which has influenced the kinetics of the mixture and drastically alters the size and shape of the nanoparticles. The radio wave in microwave oven is utilized to activate compounds or secondary metabolites in extract to reduce metal salts. Radio wave at a specific frequency is absorbed by extract components (phytochemicals and secondary metabolites) or activates certain extract enzymes to reduce metallic salts for stable nanoparticle production. As a result, microwave oven-assisted silver nanoparticles form in less time and are therefore the fastest way to synthesize [18].
