Rice Husk-Derived Nanomaterials for Potential Applications

Abstract

Agricultural waste reuse has been gained much interest in various environmental and industrial aspects. The agricultural waste is a rich source of various nanomaterials such as nanosilica (NS), nanocarbon (NC), and nanozeolite (NZ). Through the rice planting to the final product, 20% husk was left as a by-product from the total weight, so-called rice husk (RH). The economic consideration of RH refers to the rich source of NS, NC, and NZ, where RH contents are 70–85% organic matter and inorganic residues (20–25%). Also, rice husk ash (RHA) contents are 60% silica and 10–40% carbon as well as another mineral’s composition. Therefore, there are many approached for producing and extracting NS and NC from RH and RHA using different effective physical and chemical recycling methodologies. The extracted NS from RH and RHA was successfully used for the development and production of NZ. The production of NS, NC, and NZ from RH and RHA is a potential approach for reducing the environmental effect and raising the economic values with highly effective materials in various applications. The valuable usage of NS, NC, and NZ is very high, which can be used in various industrial and environmental aspects such as electronics, ceramic, catalyst support, adsorbents, ion exchangers, water treatment, antimicrobial products, biosensing, and biomedical applications. In this chapter, the various extraction and synthesis methodologies for the controlled formation of NS, NC, and NZ from RH and RHA were reported. Besides, the potential usage and sustainable applications of these materials were successfully presented.