A Compendium on the Eco-Sustainable Biosynthesis of Palladium Nanoparticles (PdNPs) and Their New Avenues Towards Environmental Applications

Palladium Nanoparticles (PdNPs) are considered significant catalytic agents, along with a wide range of applications, mainly hydrogen storage and sensing, biomedical imaging, and remediation strategies. Extensive studies are being carried out on the formation of PdNPs (PdNPs) worldwide, showing the predominance of the chemical approach among various technologies for the synthesis. The traditional chemical method employed in the formulation of PdNPs contains certain limitations that have been overcome by the use of the alternative biological method, as they are meek, low-cost, and benign to ecosystems. Therefore, the present review provides an overview of the modernized techniques involved in the biological approach for PdNPs formation by utilizing various natural origins, for example, plants as well as microbes, for their enhanced stability and applications in fields of the environment. Various mechanisms and parameters involved, along with approaches utilized for the characterization of bioPdNPs, are described, with an insight being delivered on the utility of biologically synthesized palladium nanoparticles. Recovery of PdNPs to achieve a circular economy is also being focused. In addition, the future prospectus on palladium nanoparticle research is also summarized.