Impact of synthetic method and metal type on the efficiency of metal-based nanoparticles against pathogens and chemical pollutants

Abstract Metal-based nanoparticles offer a one-pot solution for pollution mitigation due to the wide range of pollutants removed using multiple mechanisms such as catalytic oxidation, reduction, photothermal degradation/transformation and magnetic adsorption. Herein, we give an insight into the effect of key factors such as synthetic method, electronic properties of metals and nature of the pollutants and their dispersion media, on the efficiency of metal-based nanoparticles in pollution mitigation. Silver nanoparticles are mostly biosynthesized and applied in the removal of pathogenic bacteria, where the removal efficiency is enhanced by the closeness in the chemical resemblance between the biological corona of extracts used in the synthesis of the nanoparticles and that of the bacteria colony biofilm or cell membrane/wall makeup. On the other hand, chemical and physical methods are used to synthesize most transition metal-based nanoparticles for versatile applications in curbing various biological and chemical pollutants. In general, pollutant removal efficiency increases with an increase in the concentration of the metal nanoparticles and the use of multiple metals, the availability of ligand hetero atoms and the stability of products formed by the degradation or transformation of chemical pollutants.