Green synthesized metal hexacyanoferrate based nanostructures for environmental applications

Metal hexacyanoferrates (MHCFs) are attracting much scientific interest due to their intense properties, which include variable energy band structures, unique redox properties, stability, availability, low cost, and eco-friendly catalysts compared with traditional photocatalysts. Transition metal oxides, metal sulfides, carbon derivatives, and polymers could extend electron-hole creation, improving photocatalytic efficiency and adsorption properties of MHCFs. The band gaps of MHCF are usually between 1.31 and 2.52 eV, generating e⁻ and h⁺ pairs that degrade pollutants. The surface area, charge, and functional groups of MHCFs impact the adsorption and degradation of contaminants. The shift towards green synthesis is necessary for environmental sustainability, health, and safety. This article concludes that the green synthesis of MHCFs and various applications of MHCFs, like adsorbing and degrading pollutants and selective removal of heavy metals and radioactive ions, make them efficient candidates for water treatment. These are effective for water treatment over a long period due to their stability under various environmental conditions. A handful of reviews on MHCFs individually discuss one of their applications, but this review provides all the information about their green synthesis and environmental applications. A comprehensive study of MHCFs has been conducted for five years. The investigation analyzed sustainable MHCFs, production, challenges, and potential future.