Synthesis and Structural Characterization of G-SBA-IDA, G-SBA-EDTA and G-SBA-DTPA Modified Mesoporous SBA-15 Silica and Their Application for Removal of Toxic Metal Ions Pollutants

Abstract

Modified mesoporous SBA-15 silica materials (G-SBA-IDA, G-SBA-EDTA and G-SBA-DTPA) (where IDA, EDTA and DTPA represent iminodiacetic acid, ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid, respectively) were prepared by treatment of grafted monoamine or diamine or triamine mesoporous SBA-15 silica (G-SBA-N, G-SBA-NN , G-SBA-NNN) nanomaterials with ethylchloroacetate, followed by acid hydrolysis of ester groups. These materials were characterized by several techniques including transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), small angle X-ray scattering (SAXS), thermal analysis (TGA) and X-ray photoelectron spectroscopy (XPS). TEM and BET analysis revealed that the IDA functionalized amine mesoporous SBA-15 silica materials have maintained their mesostructure after modification of the amine mesoporous silica with ethylchloroacetate. Thermal analysis (TGA-DTA) and FTIR confirmed that ethylchloroacetate groups are covalently bound to the amine groups. The acid forms of IDA functionalized materials showed high potential for extraction and removal of heavy pollutant metal ions (Co2+, Ni2+, Cu2+and Pb2+) from aqueous solutions.