Sustainable synthesis of silica nanoparticles from agricultural waste and its utilization in modern technology: A review

Abstract

ABSTRACT Nanotechnology is widely used in a variety of technologies, including agriculture, biosensors, fertilizers, food packaging, electronics, semiconductor technology, and energy storage. Silica nanoparticles (SiNPs) have shown a broad array of applications in a variety of disciplines due to their distinctive properties such as stability, biocompatibility, surface reactivity, tunable pore size, and high surface area. SiNPs are widely used in biomedicine and target drug delivery due to their ease of surface functionalization. SiNPs have traditionally been synthesized using chemical methods that require advanced equipment, high costs, and hazardous materials, resulting in a long-term negative impact on the environment. Global challenges such as climate change and environmental concerns have compelled scientists to develop effective, economical, and environmentally friendly methods of synthesizing SiNPs. As a result, the focus has shifted to bioinspired protocols that employ industrial waste, agricultural waste, plants, fungi, worms, bacteria, yeast, and microorganisms in compliance with the green chemistry principle and sustainability. This review focuses on the green, economical, and sustainable methods for synthesizing SiNPs from agricultural waste and their utilization in different fields. Among many agricultural wastes, rice husk (RH) and wheat husk (WH) stands out due to the high percentage of silica in their chemical composition, making them an easier and more effective source of synthesizing SiNPs. This study provides an in-depth look at catalytic and biomedical applications of SiNPs, as well as their greener synthetic methods, which will be useful for future work on green principles and sustainable development.