Synthesis of Iron-Carbon (Fe⁰-C) Nanocomposite and its Use for the Removal of Rhodamine-B and Hexavalent Chromium from Aqueous Solutions

Abstract

Contamination of water resources by industrial effluents consisting of organic (e.g., dyes) and inorganic (e.g., heavy metals) pollutants is a significant environmental challenge. Treatment techniques that can efficiently target multiple co-contaminants are critically needed to achieve both performance and cost efficiency. In this study we employed a novel approach to synthesize a nanocomposite material consisting of a zerovalent iron (Fe0) core and a carbon shell (C), and investigated its ability to simultaneously remove toxic hexavalent chromium (Cr (VI)) and rhodamine B dye (RhB) in batch aqueous solutions. Advanced characterization techniques revealed the uniform distribution of carbon on Fe0 particles in the size range of 60-85 nm. The batch removal experiments showed a Cr (VI) removal of 50% and RhB removal reached 93% in mixed matrix systems. The removal capacity increased from 16 to 33 mg/g for Cr (VI) and from 2.4 to 5.5 mg/g for RhB when the particles were tested in a mixed matrix compared to those in individual contaminant systems. Removal of contaminants was achieved most likely due to the combined adsorptive and reductive properties of the nanocomposite. Overall, the study demonstrated the strong potential of Fe0-C nanocomposite particles in targeting and treating both organic and inorganic contaminants. Results from this study may be useful in developing and optimizing nanocomposite materials for the removal of multiple contaminants in complex aqueous matrices.