In this study, magnetic cobalt(II/III)oxide@iron (II/III)oxide (Co₃O₄@Fe₃O₄) nanoflowers were grown by hydrothermal synthesis technique to use them for the removal of Cr⁶⁺ ion in real samples. X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) were used to characterize the morphology and chemical composition of Co₃O₄@Fe₃O₄ nanoflowers. Flame atomic absorption spectrometry (FAAS) was used for Cr⁶⁺ analysis in the adsorption study. The optimum conditions (eluent concentration and type, pH of the solution, adsorbent material amount, solution volume and sonication period) were determined for the removal of metals. Co₃O₄@Fe₃O₄ nanoflower provided 53.3-fold enrichment of the plant samples. Co₃O₄@Fe₃O₄ nanoflowers managed to achieve 99.3% Cr⁶⁺ recovery rate in 10 mL eluent volume, for optimum condition. As a result, it is predicted that Co₃O₄@Fe₃O₄ nanoflowers have a high adsorption capacity and can be used as an efficient adsorbent material for waste removal.