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. C-13 CP MAS, Si-29 MAS NMR, UV-visible absorption and PL spectroscopic data suggests the incorporation of bridging organic diimine fluorophore in the solid mesoporous material. N-2 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. (C) 2009 Elsevier Inc. All rights reserved.