A Review on Agricultural Wastes–Based Green Metal and Metal Oxide Nanoparticles

In the past two decades, a plethora of metal and metal oxide nanoparticles have been synthesized via different conventional synthesis methods such as chemical vapor deposition, thermal decomposition, hydrothermal synthesis, solvothermal method, and pulsed laser ablation and have been employed in various fields of applications. In the conventional synthesis methods, some toxic and costly precursors are used, which can cause serious environmental and health issues. Therefore, the proper selection of raw materials and synthesis methodologies for generation of nanoparticles and innovating ideas for new sustainable technologies are the most preceding needs. To achieve the goal, on the onset of the twenty-first century, agricultural wastes such as rice husk, corncob, sugarcane bagasse, palm ash, bamboo leaves, and coconut shell husk were acknowledged as economical precursors to produce green nanoparticles. Synthesis of such nanoparticles from agricultural wastes is green, cost-effective, energy saving, eco-friendly and also help in resolving the problem of waste disposal. In this chapter, we have discussed the types of agricultural wastes, their sources, and a few examples. Then we outline the synthesis of different metal and metal oxide nanoparticles from these agricultural wastes. Additionally, we also review general applications and future perspectives of such metal and metal oxide nanoparticles, which are extracted from agricultural wastes. Some concerns linked with usage of these nanoparticles are also outlined.