“…27,28 Different materials can be used as adsorbents, such as amino-functionalized silica gel, 29 chitosan/graphene oxide nanocomposite aerogel, 30 supramolecular ionogels, 31 metallogels, 32 supramolecular gels, 27,28,33 polymer gels, 20 fly ash, 34 and metal complexes. 35,36 Dye adsorption via reliable, non-toxic, eco-friendly, and low-cost materials is more important. Further, the implementation of hybrid gels for the removal of toxic dyes was also reported.…”