ABSTRACT
Metallic nanoparticles have recently been utilized in the practical domains of nanofabrication, nano-biosensors and optoelectronic devices. Nanocatalysis is an essential branch of nanoscience, where nanoparticles (NPs) are used as catalysts. Metallic nanocatalysts are grouped into three sections: homogeneous catalysts, heterogeneous catalysts, and biocatalysts. The techniques or mechanisms of synthesis can be classified under two heads: the thermodynamic equilibrium approach and the kinetic approach. Under the kinetic approach, preparation of gold nanoparticles was reported inside micelles or in microemulsions by hampering the growth reaction in a circumscribed space. The synthetic strategies for the process of encapsulation should be carefully selected, keeping in mind the properties of the materials used for encapsulation and also the requirements of the metallic nanoparticles. Colloidal synthesis of metallic NPs requires four basic ingredients: metallic precursor, surfactant, dissolvent, and eliminator. The process of epoxidation of olefins in the gaseous phase well explains the mechanism of shape control in metallic nanoparticles.
