Metal Oxide Nanoparticles’ Green Synthesis by Plants: Prospects in Phyto- and Bioremediation and Photocatalytic Degradation of Organic Pollutants

Abstract

Over the past few decades, the production of metal oxide nanoparticles (MONPs) has developed into an exciting and sophisticated research area. Green metal oxide nanoparticles have played an extremely imperative role in various fields, including biomedical, environmental, energy, agricultural applications, catalytic, bioactive, antibacterial, poisonous, and biocompatible. To achieve sustainability and adopt environmentally friendly practices, the production of MONPs is now increasingly focused on exploring green chemistry and alternative pathways. When made using green synthesis techniques, the metal oxide nanoparticles are especially important because they do not require external stabilizers, capping agents, dangerous chemicals, or harsh operating conditions (high pressure and temperature). Plant-mediated synthesis of different MONPs using either whole cells or extracts has several advantages, including rapid synthesis (compared with other biogenic processes (using fungi and bacteria)), being more stable than other types, being available in nature, and being non-toxic. This review provides a comprehensive overview of the green synthesis of MONPs using plant parts, factors affecting the synthesis, and the characterization of synthesized NPs. Additionally, it highlights the potential of these environmentally friendly nanoparticles that are widely used to treat environmental pollutants, including the removal of heavy metals, antibacterials, and the degradation of organic pollutants.