Adsorptive removal of Fe(III) using gallic acid anchored iron magnetic nano-adsorbents synthesized via two different routes under microwave irradiation

Abstract

Under microwave solvent free conditions, bare iron magnetic nanoparticles (Fe₃O₄-MNPs) were silica coated, amine functionalized and gallic acid grafted, in presence and absence of tetraethylorthosilicate (TEOS).  The synthesized adsorbents in both cases were followed up by Fourier transform infrared (FT-IR), scan electron microscopy (SEM) and transmission electron microscopy (TEM) analyses to verify and compare the progress of surface modification.  The results of medium stability as criteria for potential coating and values of metal uptake capacity support the possibility of the direct use of alkoxysilanes as alternative to TEOS not only for coating but also for amine functionalization.  This is strengthened by almost equal capability of gallic acid anchored adsorbents for extraction of trace concentrations of Fe(III) spiked natural water samples.