A fluorophore grafted 2D-hexagonal mesoporous organosilica: Excellent ion-exchanger for the removal of heavy metal ions from wastewater

Highly ordered 2D-hexagonal luminescent organic–inorganic hybrid mesoporous silica (LHMS-2) containing a fluorophore inside the pore walls has been synthesized hydrothermally by using a non-ionic triblock co-polymer surfactant F127 as template under strongly acidic synthesis condition. XRD and HR TEM image analyses suggest the formation of highly ordered 2D-hexagonal mesophase from a mixture of diimine organosilica and tetraethyl orthosilicate (TEOS) precursors. 13C CP MAS, 29Si MAS NMR, UV–visible absorption and PL spectroscopic data suggests the incorporation of bridging organic diimine fluorophore in the solid mesoporous material. N2 sorption data indicates high BET surface area together with type IV isotherm, characteristics of well-defined mesopores for this material. This fluorophore grafted mesoporous material shows very strong affinity for metal cations like Fe3+, Zn2+, Cd2+ and Hg2+, and thus can be very efficiently utilized for the removal of these heavy metal ions from wastewater.