Silica centered aerogels as advanced functional material and their applications: A review

Silica aerogels have piqued the interest of researchers because of their distinct nanoporous networks, composed of interconnected silica nanoparticles and high-volume nanosized pores. They are produced using the "sol-gel" process, which involves precursor preparation, gelation, aging, and drying and is a reliable process for making silica aerogels. The hydrophobicity or hydrophilicity of silica aerogels can be attributed to either the synthesis process or the surface silanol groups. Silica aerogels used in marketable and high-tech engineering applications such thermal insulation, separation, coatings, sensing, and catalysis due to their unique features. This article highlights silica aerogels' intrinsic properties, potential applications, and recent scientific advances. Moreover, it provides an overview of the synthesis, processing, and recent applications of aerogels in air purification, such as CO2 capture and VOC removal, and in water treatment, including the removal of oil and toxic organic com-pounds and heavy metal ions. Significant features of the science behind these applications are described, and when relevant, critical issues affecting aerogel application are noted.