New nanoadsorbent based on magnetic iron oxide containing 1,4,7,10-tetraazacyclododecane in outer chain (Fe3O4@SiO2-cyclen) for adsorption and removal of selected heavy metal ions Cd2+, Pb2+, Cu2+

Abstract

Magnetic Fe3O4@SiO2-cyclen nanoparticles were prepared and used as adsorbent for Cd2+, Pb2+ and Cu2+ from aqueous solution removal process controlled with differential pulse anodic stripping voltammetry (DPASV) and hanging mercury drop electrode (HDME). Nanomaterial was synthesised in three-step process co-precipitation of Fe3O4 core, coating with silane and N-(3-(triethoxysilyl)propyl)-1,4,7,10-tetraazacyclododecane-1-carboxamide silane functionalisation. The effectiveness of each step of the synthesis was confirmed using scanning electron microscopy (SEM), high-resolution X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (pXRD) and fourier-transform infrared spectroscopy (FT-IR) techniques. The Fe3O4@SiO2-cyclen nanoparticles were employed for Cd2+, Pb2+ and Cu2+ ions elimination from individual and mixed solutions by carrying out titration with a suspension of nanocomposites. The binding level for all ions both in the individual solutions and in the mixture was very similar at high levels. For Cd2+ and Cu2+ ions sorption efficiency level was from 83% to 89%, while for Pb2+ ions it was slightly lower at the level over 73%. In all cases, the equilibrium adsorption capacity parameter was over 1 mg/g and reached definitely higher values for individual ions solutions. The research results revealed that Fe3O4@SiO2- cyclen nanoparticles can be a promising adsorbent for magnetic heavy metal ions water treatment agents.