Removal of Toxic Chromium Ions in Aqueous Medium Using a New Sorbent Based on rGO@CNT@Fe 2 O 3

A facile hydrothermal route is investigated to prepare a new sorbent based on rGO@CNT@Fe 2 O 3 . The synthesis is easy and does not involve complex chemistry. The as prepared sorbent are characterized by scanning electron microscopy (SEM), X-ray diffraction, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). Chromium ions adsorption capacity of sorbent reaches 91.7 mg/g at contact time of 240 min at 298 K, and the data is fitted to Freundlich adsorption isotherm model, with second-order kinetics. Further analysis of the mechanism proved that the binding of Cr (VI) to sorbent was mainly a synergistic effect of electrostatic attraction, and ion exchange reduction. Overall, these results shed new light on the search for new composites and revealed the potential practical application of rGO@CNT@Fe 2 O 3 in the removal of heavy metals in solution. Graphical Abstract