Aerogel, xerogel, and cryogel: Synthesis, surface chemistry, and properties—Practical environmental applications and the future developments

Aerogels, xerogels, and cryogels are sol-gel derived mesoporous materials with many extraordinary properties such as low density, high porosity and tunable surface chemistry and they have an ongoing interest especially in environmental remediation applications. This chapter gives an overview of both the synthesis and uses of these materials for environmental applications. First, the production procedures, affecting synthesis parameters and the strategies about altering the surface chemistry of the aerogels, cryogels, and xerogels for an efficient treatment will be described. Then, the recent studies covering the applications of aerogel-based materials in adsorption applications for CO 2 and volatile organic compounds removal from air and heavy metals ions, oils and organic pollutants removal from water is summarized. The catalytic applications of them for the decomposition of inorganic and organic pollutants from terrestrial and aquatic environments are also reported. Lastly, the main drawbacks of practical applications and future developments are highlighted.