Synthesis of nanosilica from agricultural wastes and its multifaceted applications: A review

Agricultural wastes management is one of the biggest burdens in the 21st century. To reduce pollution from agricultural waste, different types of research have been conducted to convert agricultural wastes into value-added products. In recent decades, agricultural wastes are utilized as source material for nanoparticle synthesis. Nanoparticles with large surface area, small size, biocompatibility, and adjustable functionalization are now booming in different areas of science and technology. Among different types of nanoparticles, the silica nanoparticles (SiNPs) were favored to synthesize from agro-wastes as the major agricultural crop residues are silica enriched, especially the cereal crops. Moreover, the bound silica in the agricultural wastes is conventionally extracted by thermal, chemical, and biological treatment. Owing to the structural flexibility, tuneable pore size, and less toxicity made the SiNPs are more attractive to use in various fields than other metallic nanoparticles. SiNPs are now extensively used in biomedical, agricultural, and environmental remediation purposes. This review paper is an assemblage of different approaches aimed to synthesize nanosilica from agro-wastes along with its potential application areas. [Display omitted] •The potential agrowastes for synthesis of silica nanoparticles have been evaluated.•Detailed methodology for extracting silica nanoparticles from agricultural wastes has been presented.•The use of silica nanoparticles in a variety of applications was also investigated.