A comprehensive review on plant mediated nanoparticles: Green nanoparticles and their applications for water remediation

Plant mediated green nanoparticles (NPs) have grabbed substantial consideration as promising alternates to traditional approaches that minimizes the use of toxic chemicals. The phytochemicals like flavonoids, polyphenolics carbohydrates etc. present in plant extracts contain functional groups like -OH/-C=O that bind with metal ions to facilitate chelation, and finally influence NP size and other morphologies and stability. The review presents an overview of green NPs synthesis and their efficacy to remove toxic contaminants such as organic pollutants, drugs, dyes, heavy metals, and other pathogenic microbes from water. The review delves into plant mediated green NP synthesis from stem, root, flower, leaves extract, structural modifications, their stability, and underlying adsorption or photocatalytic mechanisms for water remediation. The review further discusses key challenges with plant mediated NP synthesis including stability and reproducibility due to NP agglomeration along with toxicity which requires LCA sustainability consideration. The review is compilation of recent advancement and future directions needed to transform lab-scale plant mediated NPs to large scale sustainable water remediation techniques.