Green synthesis of metal oxide nanostructures using naturally occurring compounds for energy, environmental, and bio-related applications

In recent years, naturally occurring compounds found in plants (also known as phytochemicals) have found increasing application in the synthesis of metal oxide nanostructures due to their multi-role as reducing agents, capping agents, and/or complexing agents. Furthermore, the utilization of natural agents, such as phytochemicals provide a green and sustainable way for fabricating metal oxide nanostructures compared to conventional chemical methods. This perspective will cover various types of plant-derived phytochemicals which have been employed in the preparation of metal oxide nanostructures, including their roles and the associated formation mechanisms. This review will also discuss some prospective applications of phytochemical-derived metal oxide nanostructures for energy storage, environmental remediation, and bio-related applications. Finally, some perspectives on the future direction of the synthesis of metal oxide nanostructures via green chemistry will be provided.