Terpyridine-based smart organic–inorganic hybrid gel as potential dye-adsorbing agent for water purification

A terpyridine-based organic–inorganic hybrid gelator possessing triethoxylsilane moiety was synthesized and its adsorption capacity for aromatic dyes in the absence and the presence of metal ions such as Zn2+ and Cu2+ was measured by UV–vis spectroscopy. From aqueous solutions of dyes, the hybrid gel, in the absence of metal ions, adsorbed 97.4% for basic blue 41, 94.2% for crystal violet, and 41.5% for bromocresol green. When metal ion was present, the adsorption capacity of dried hybrid gel 1 for the anionic dye bromocresol green significantly increased due to the enhanced electrostatic interaction between cationic gel and anionic dye. Thus, this hybrid gel can efficiently adsorb various toxic dyes in water.