Environmental remediation potentialities of metal and metal oxide nanoparticles: Mechanistic biosynthesis, influencing factors, and application standpoint

Abstract

Nanotechnology has emerged as a promising field in the development and modification of new nanostructured materials for multifaceted applications, including environmental remediation. Nanoparticles based trendy materials as robust adsorbents and efficient catalytic constructs offer unique structural, chemical, and multifunctional properties, such as high mechanical strength, morphologies, and diverse composition, which promise its use in catalysis, adsorption, degradation, and so on. Herein, we report contemporary advances in metal and metal oxide nanoparticles and their strategic role in environmental approaches, mainly due to the great interest and need for scientific community. The concept of green nanoscience is a practical application of advanced nanotechnology and, therefore, following this relationship between nanotechnology and green chemistry, the biosynthesis of nanoparticles has evolved as an excellent approach. In view of the different techniques widely explored for nanoparticles synthesis, it is possible to state that the main methods currently used are expensive, environmentally harmful, and inefficient regarding the use of materials with applications viewpoints. The natural extracts contain several secondary metabolites that assist in the redox process of metal ions in nanoparticles. Special attention is given to synthetic biological procedures and solvent systems when compared to nanoparticles obtained by non-biological methods. Here, we review recent advances in mechanistic approaches to nanoparticle biosynthesis, as well as the parameters influencing production rate, size, morphology, and their environmental implications. It will become evident that the environmental implication is a rapidly growing field. • The mechanism and factors affecting biosynthesis of metal and metal oxide nanoparticles are discussed in detail. • Biomass acts as reducing and stabilizing molecules in biosynthesis. • Physical chemistry techniques to characterize nanoparticles are outlined. • Environmental remediation potentialities of biosynthesized nanoparticles.