Functionalization of nZVI nanoparticles with dipicolinic acid by one-pot synthesis and testing of PDCA-nZVI material properties in cadmium removal from water

The low-cost method of functionalization of zero-valent iron nanoparticles (nZVI) by dipicolinic acid (PDCA) by one-pot synthesis was studied in this work. The chemical reduction of iron salt with concurrent addition of ligand was performed using different molar ratio of starting reagents. Functionalization of nZVI was confirmed by FT-IR spectroscopy. The formation of oxide layers on the core of iron particles that consists of magnetite and feroxyhyte was confirmed by the XRD method. Morphology of obtained material was examined by SEM study and it revealed the formation of short-chains of spherical particles by use of equimolar ratio of reactants. The appearance of ellipsoidal aggregates was observed by use of reagents molar ratio of 1/2. The performance characteristics of obtained materials were tested in cadmium removal from water solutions. Concentrations of cadmium in solutions were determined by ICP-OES measurements. The efficiency of removal of cadmium was tested on bare nZVI particles, one-pot synthetized PDCA-nZVI particles, and particles obtained by subsequent incubation of PDCA onto nZVI. The results of the measured hydrodynamic diameter and zeta-potential in solutions were correlated with adsorption characteristics of prepared functionalized materials. The most efficient adsorption of cadmium was observed by exploiting PDCA-nZVI nanomaterial that was obtained from one-pot synthesis.